2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)

Download working 2Bar files here: 01-30-2009, 10:46 PM Post #238. http://www.mediafire.com/file/zo3zwgnwzm2/Dan_156_OpenLoop.lt1

10-18-08: IT WORKS! (all summer) 2 BAR ON STOCK LT1 PCM - Everything you need is in this original post. Specific questions/answers are in the following posts (there's alot of them).

3-11-08: MAJOR UPDATE/SOLUTION IF YOU RUN 2 BAR MAP on STOCK PCM YOU NEED TO DISABLE BARO RESET ON YOUR TUNE OR YOU COULD POTENTIALLY BLOW UP YOUR MOTOR BY ENTERING WOT AT THE "WRONG" TIME. New TUNERCAT definition file avail. Not sure about update for LT1_Edit.

I discovered the BARO resets (matches MAP PRESSURE) all the way up to 3600rpms under WOT (or more than 37%TPS). This is OK if you run WOT starting under 3600rpms everytime BUT if you start your car and lightly rev to say 4000rpm you could then enter WOT and the BARO will stay at the KEY ON MAP value (usually 52kpa on a 2bar setup). This makes fueling VERY LEAN running WOT at 52kpa BARO compared to WOT at 65kpa BARO. THis also means once you lower the BARO RESET to something like 1000rpms or lower your WOT fueling will now be based off of ~52KPA everytime (consistency) and you will need to increase fueling accordingly (I see about ~10%more VE needed to come even close - I lowered my injector flow rating to lower the amounts of VE needed for the same AFR since VE are limited to 99%).

3-13-08 Minor Update - Fixed a prob with my 83lb injectors having slightly rich idle + rich decel (just above the limit of Decel Fuel Cut Off)...Plus there was this surge upon injector re-light since injectors were over fueling.. I compensated with reduced timing upon re-lite but now the problem is gone... the right way. Tunercat shows stock min PW set at 1.4ms, slight decel and idle mine was 1-1.3... changed to 1.0 and all fixed... hold 14.7 on decel and 14.7 on idle. Amazing control for stock PCM I think.


Information is below... My setup is in the signature...


Original Thread “Speed Density tune, easy?” started by VK, with a lot of input from engineermike and STSturboLT1 located here: http://www.camaroz28.com/forums/showthread.php?t=500809

Brings me to my point… (bolded points below are the main points I picked up on by reading everybodys posts about SD tuning…

I have a 7 psi forged 383 getting ready to run 15psi on the stock PCM with 83lb injectors and my question is:
1) Whats the SAFEST way to get there other an running a FMU or PE mode (which after the MAP maxes out at 2000rpm and the MAF maxes out at 4500RPM I’m left with only RPM/PE enrichment/100kpa timing…

Main Points by author:
1) “VK”: I usually get my base tune done by Madz28, but if at all possible i'd like to do this myself. I'm completely maxing out my MAF by 5K rpm (471g) so i need to switch to speed density or get a new maf. Sounds like Speed Density mode is a given if you run over ~5-6psi boost.

2) Sweetred95ta: From what I understand, it's not that easy to switch to a 2-bar MAP. I honestly haven't heard of anyone that has successfully done it. Tuning in SD is pretty easy. Instead of making fuel corrections in your MAF calibration tables, you'll make them in the VE tables. Add to the numbers and it'll feed it more fuel; lower the number and it'll take fuel away. Just log the car and find out where it's wanting to run lean or rich, then make the appropriate changes. “Add to the VE tables to add fuel, subtract from the VE tables to take away fuel” This is better than the single lined PE % line…

3) Engineermike: Alvin at PCMForLess did a '93 one time, but said it was a real pain and doesn't recommend anyone else try it. I'm going to give it a try eventually and if it doesn't work, switch to MS2 for fuel-only.

Sounds like it is possible but is a lot of work…?? A lot more work trying to get something else to work is what I understand…

4) LSxManiac: First of all, you can't use a 2-bar map sensor without A LOT of calculations because the PCM is designed to operate with a 1-bar sensor. Second point, depending on the amount of air the engine is using, you may not need to convert to speed density. If MAP goes to 100 kPa and the MAF is maxed out, you can just crank up the PE table values to add more fuel. At this point, the system is functionally in speed density mode because the MAF (being maxed out) is no longer supplying relevant information. This may not work at high boost pressures, or if you're marginal on injector size, but I've tuned a bunch of supercharged cars (including some 86-89 models) using this method.
a. This works fine with the lower boost guys (including me up until now when I think about boost beyond 6psi)

And finally… the reason for this post…
STSturboLT1” This is a pretty old thread, but I just thought I'd share that I recently got my car running a 1.5 bar tune in SD mode with the stock LT1 PCM. Here's what I did to modify the tune by dividing the VE tables, moved the columns accordingly. I realized that 100% is the limit for the VE cells, and when in boost the values needed could be higher than 100%. So I divided all VE cells and the injector constant by the factor of the MAP sensor (STSturboLT1 used a 1.5 bar setup to divide by 1.5) . I (STSTurboLT1) the same basic approach for the spark advance tables, except they were easier since there was no scaling involved, just moving columns around.

Once all the tables were adjusted, I started the car up. It fired up right away and ran ok…

I ((STSTurboLT1) went to a speed density tune because the car has better throttle response compared to using the MAF. Plus I'm sick of always having to clean the MAF, and the fact that it's just a restriction, albeit small, on the intake. I just thought some of you might be interested.

Problem = stock PCM never recognized boost, The new MAP sensor fools the PCM to recognize boost being within the 100 kPa limit. More trickery is needed by scaling the injector constant, to make the PCM add more fuel than it intends. I originally planned to tune WOT strictly with the VE table, and set the PE values to 0, but I worried hitting the 100% limit in the VE tables…. THIS IS WHERE I CONTINUED to realize a 2 BAR MAP on a Stock PCM WORKS (proper scaling results in a stock LT1 PCM Boost referenced Speed Density Closed Loop Tune)

Long story short…

My 7psi 383 (soon to be 15psi) using the stock LT1 PCM references boost (0psi = 51kpa, 7psi = 75kpa, 14psi = 100kpa) I did the following based on everybody’s previous experience

1) Since STSTurboLT1 is the first guy that I read that actually converted it to a 1.5 bar setup and transferred the tables to re-calibrate the PCM into 1.5bar mode… I did the same thing but using a 2 bar sensor and scaling everything by 2 (scaling the VE tables, timing, open loop AFR vs Load, etc by 2) then once it ran I took it one step further according to his statement about the “additional trickery by scaling the injector constants…”
a) divided my injector flow size by 2, (83lb original changed to 40lb)
b) Dividing all the VE% by 2
c) TO FIX LEAN TIP IN STUMBLE I lowered my injector flow rating a considerable amount after I divided by 2 - 83lb/2 = 41lb.. this still had lean tip in like the 1 Bar tune so I lowered it to 30lb and lean tip in DISAPEARED! (all other fueling needs to be leaned out obviously


This resulted in a base tune to run (actually would only idle leanly and stall once throttle was applied…) then I ran in closed loop and used VE Master to adjust the VE tables…

The result for me + others
1) Same (actually better) idle and cruise driveabilty – probably because I was in MAF mode prior to this Speed Density/2bar conversion and MAF just isn’t as good as Speed Density (assuming Speed Density is tuned properly)
2) Better startup – only because before all settings were what I thought “looked correct so I did not want to drift to far from the “correct settings” (now everything scaled by ½ so I have no problem reducing/adding settings beyond what should be normal
3) Tuning AFR based on manifold pressure and RPM (not just RPM alone using PE vs RPM – I set that to 0 across the board and dialed in a consistent 11.8-12.2AFR @ WOT based off Wideband O2 readings) with 0% in the PE AFR vs RPM column… This results in infinite AFR adjustment regardless of what manifold pressure is… READ MAJOR UPDATE AT TOP OF THIS PAGE
4) Better overall timing resolution (with the 1 bar tune timing is locked to 100kpa across the board regardless of actual throttle/manifold pressure

I will be trying this on my setup as soon as we get some better weather around here, I think I can make it work!

Another person tried this with GREAT success (sounds like he also experienced better results with the 2 bar SD tune than with the 1 bar MAF tune)

Details here:
http://www.camaroz28.com/forums/showthread.php?t=500809&page=3

My story with a 1.5 bar SD tune is at the link you provided. Although the car ran ok with the MAF, I always battled surging and bogging under acceleration during normal driving, even after the fuel trims were dialed in. The throttle is more responsive in SD mode, making it more enjoyable to drive. I'm an engineer, so it was a fun side project. It was actually much simpler than I thought it would be to get it running correctly.

Another person tried this with GREAT success (sounds like he also experienced better results with the 2 bar SD tune than with the 1 bar MAF tune)

"GREAT" is an understatement. The only thing I'm upset about is the fact I didn't do this sooner. I was waiting for moates to develop the real-time tuning for the LT1 so it would be easier to tune, but it turns out it's pretty easy to tune by scanning and flashing. It only took me about 4 flashes to get it dang close.

All this and I'm tuning in Open Loop, so there is no O2 corrections that would mask an imperfect base map. I imagine once I get the base map close enough, I'll enable Closed Loop and it'll get even better. On the current tune, it's staying between 13 and 15 A/F at idle, accel, and cruise (all in vacuum - much richer in boost). I could probably put it in Closed Loop now and it would compensate, but I'd rather get it closer to perfect before doing that.

Mike

You should try putting in closed loop then run the Datamaster logs through VE Master... try try that 2-3 times see what it does. I left my VE cells slightly on the rich side to the PCM is pulling fuel slightly most of the time, rather than adding fuel.

If you have a problem with closed loop it's probably because the BLM/MAP boundries need to be adjusted... again VE Master makes it easy to see what cells are getting hits and how often. YOu want the most wide spread BLM cell hit to make the most of closed loop tune.

There's a site around somewhere from the guy who invented the Versafueler... so a search his site goes through everything in detail.

I think we should setup a test bed, get a small tank attach the 2 bar map and the 3 bar map along with a pressure fitting to either put a vac pump or a compressor. first test for the most vac a motor will develop 20-30 psi vac or so. attach each sensor to the car and using freescan note down which kpa cell the computer is in. then test for 10 psi vac, atm, and different levels of pos pressure etc etc etc. this way we have a very definitive way of scaling the tables can even make a nice excel sheet too :D

Well I just sent the tune to you, let me know when you get that testing done!

dookie would you mind shooting me a copy to compare to mine? shankels1@yahoo.com i've written and tested one of my own but the car just ate the accel opti so im just bench racing for a week or so...

should be in it's way. I got a MSD pro billet and ate that in 2 weeks... looks like they forgot to add locktite to one of the rotor screws.. got a replacement and took it apart and see they forgot locktite again so I locktite myself and so far no more problems.

I've been steadily driving and tuning this thing. It's getting better all the time. I probably could have called it good a few iterations ago and never looked back, but I guess I'm a perfectionist.

I've had to polish a bit on the 25-30 kpa at 1600 - 2600 ranges. It seems as though there's a lean spot at about 27 kpa in that range, you can't change the values there so I guess I'll have to live with it. That's the sacrifice I suppose with 2 bar on the stock ECM. BTW, the lean spot is about 16/1 and it's not even noticeable when driving. I wouldn't know it was there if it wasn't for the WBO2. Roll on the throttle to 30 kpa and it runs 14.5 and back off to 25 kpa and it's 14.5 there too.

I've also had to add a whole bunch of fuel in the 45 - 55 kpa and 600 - 2200 rpm range to cure the lean tip-in problem. It's almost totally gone now. You really have to snap the throttle open quick to see a spike on the A/F gauge.

I made a full throttle pull tonight and it was scary fast, but it always is in the cold. A/F started out around 12.5 and richened up to 10.5 by the top. I'm running Methanol injection, which skews the tune results. I plan to phase that out over time as I get the fuel map straight.

Mike

Nice to hear Mike, I can't wait to give this a try on my car!

I have a 6 speed and the 2 bar is smooth, the only "problem" if you call it that is because of the cam (cam surge) but it's very small and not due to AFR or the tune... I wouldnt be able to detect it with an automatic but with my aluminum flywheel and springless twin disk clutch it sometimes shows it's ugly face, sometimes when cruising at 30-40mph, or when idling along in 1st gear in a parking lot.

In the video below it didnt even show up while on the dyno... you can hear the responsiveness after the pulls I kinda blip it a little.

I am really interested in how this is working out for you guys. I have a couple of questions:
1. Would this also work on OBD2 cars?

2. Do you think it would be a good idea try this tune unboosted first in order to get the drivability sorted out and then add boost?

Thanks,
Subscribing

Where do you get a 2 bar map sensor? I think this is going to be my tuning option right here b/c I dont have the money for an aftermarket system right now.

This should work exactly the same for OBDII.

2 Bar MAP from the older Sunbird Turbo from mid 1985-90 is what I have.

Running unboosted shouldnt matter, just get on the boost slowly/limit rpm as you tune it.

Is there an easy way to identify a 2 bar map sensor? I got a sensor here that was sent with an old T-trim set up I bought a while back. I believe its a 2 bar. The sensor is made by wells and has a orange/red insert at the wiring connection. I tried looking up the number printed on the sensor on wells site, but it comes up with nothing.

Thanks,

Eric :D

This should work exactly the same for OBDII.

2 Bar MAP from the older Sunbird Turbo from mid 1985-90 is what I have.

Running unboosted shouldnt matter, just get on the boost slowly/limit rpm as you tune it.
I see you have 83lb injectors, who makes them, and what converter box are you running?

I see you have 83lb injectors, who makes them, and what converter box are you running?

fyi, I believe racetronics nw sells 83 lb injectors that u dont need a converter box for. The Grand National guys are starting to run them with good results

fyi, I believe racetronics nw sells 83 lb injectors that u dont need a converter box for. The Grand National guys are starting to run them with good results
They are 79lb and I'm seriously considering them, but dont see anyone running them yet.

I run the AEM box, it was the cheapest I could find. Seems to work perfect so far.

Found this a while ago:
2 Bar:
GM part # 16009886
Wells part # SU-129
standard part # AS-4
91-93 GMC Syclone & Typhoon 4.3 turbo
87-90 Pontiac Sunbird Turbo 2.0
84-86 Sunbird (actually any J-car) turbo 1.8
886, 012, 539, 609, 701

Just came up with another question, what happens if you want to run more than 15psi, should you get a 3bar sensor?

Just came up with another question, what happens if you want to run more than 15psi, should you get a 3bar sensor?

I'm finding that the lost resolution with a 2 bar does in fact slightly hurt the tuning ability. With a 3 bar, I think too much resolution will be lost.

You have to consider that most of you cruising is done in 3 columns normally (I think 50, 55, and 60 kPa). With a 2 bar, it becomes only 2 columns (25 and 30 kPa). With a 3 bar, it would probably become 20 only and there are no columns below 20.

Mike

I guess.. that being in stock form the best computer would be the ls1 computer with the added tables....

I had always assumed the stock ECM uses linear interpolation for values between cells. Based on some stuff I've seen, I'm starting to think it just rounds the value up or down to the nearest cell.

Mike

They have always said interpolation... and it might be true. I guess the problem lies in the MAPS own accuracy. Remember that they still use 0-5v range... so the more "maps" you ahve to fit in 5v the less resolution you get via the sensor ONLY. Add to that, the interpolation and you can have a huge discrepancy...

Even still.. i have tuned a few boosted engines with the ls1 computer having 0 issues at all.

One way to find out if its the computer or the sensor is to use an older type 2bar sensor like the ls1. (there is a 2 bar with the shape of the regular ls1 map sensor)...

In the end, I am sure its the lt1 pcm.. why? simple.. its too slow, proof??? do a speed density tuning with an ls1 computer vs an lt1 computer and you'll be amazed at the differences in both...

What i will do is use a Pro-M maf with yet another converter to patch up the stock pcm....

I wish the bs3 controlled the cluster well...

In the end, I am sure its the lt1 pcm.. why? simple.. its too slow, proof??? do a speed density tuning with an ls1 computer vs an lt1 computer and you'll be amazed at the differences in both...


Once again Im not seeing one issue at all with the 2 bar on the LT1 PCM (no issues = no problems = nothing worth improving). Specifically what would I be amazed at when comparing to LS1 pcm? I have instant crisp throttle response at any rpm/load level (even with 83lb injectors), no lean/rich spots and no timing problems, even running closed loop.

Dont know how switching to LS1 PCM would fix improve on that. I guess a better example would be good here (I dont understand how the LT1 PCM being slower than LS1 could affect anything??). If your running a larger cam than myself maybe that could uncover something with the reduced resolution however I wouldnt benefit from more resolution at this point.

I did hear the LS1 PCM could be modified to allow 2-3 bar tunes, that's nice for obvious reasons however has nothing to do with speed of the PCM.

I think it comes down to proper tuning/cam profile since my 2 bar LT1 PCM is better than my 1 bar tune ever was and couldnt expect it to be any better since there's nothing I would improve on (unless I switch to 3 bar sensor then I'd have to do something).

BTW, im not trying to act like im puposely ignoring something just trying to figure all this out... so far I havent found a problem and trying to figure out where all the bad rap originally came from. From what I was reading alot of the negative experiences were from people who never tried it or put much time into tuning it. I do think there's less room for error with this setup.

I overcame the lost resolution with my setup (not that it would have likely been a problem anyway) by adding an op-amp circuit to the MAP sensor to scale the output voltage to maximize the use of the 0-5V range. I'm only running 7 pounds of boost but using a 3 bar sensor + circuit makes it effectively 1.5 bar. So if you were running something like 18 psi, you could add a similar circuit to scale a 3 bar sensor to ~2.5 bar to get some resolution back.

I overcame the lost resolution with my setup (not that it would have likely been a problem anyway) by adding an op-amp circuit to the MAP sensor to scale the output voltage to maximize the use of the 0-5V range. I'm only running 7 pounds of boost but using a 3 bar sensor + circuit makes it effectively 1.5 bar. So if you were running something like 18 psi, you could add a similar circuit to scale a 3 bar sensor to ~2.5 bar to get some resolution back.

It's a good idea, but I want a 3 bar but am having some minor resolution problems at 2 bar.

I would need a circuit that adds resolution in the 0 - 1 bar range, but reduces it in the 1 - 3 bar range. My 0 - 1 bar output would need to be 0 - 3 volts, while 3 - 4 volts would be 1 - 2 bar, and 4 - 5 volts would be 2 - 3 bar. I think that would work. Too bad we can't reformulate the lookup function in the ECM. . .

Seems to me that the VE changes very rapidly around 50 - 60 kPa in the 1500 - 3000 rpm range. But, once you get over about 80 kPa on up toe 300 kPa, the changes aren't much, so you dont' need much resolution there. I could probably just stick one number in the table from 100 kPa on up and it run just fine.

Mike

It's a good idea, but I want a 3 bar but am having some minor resolution problems at 2 bar.

I would need a circuit that adds resolution in the 0 - 1 bar range, but reduces it in the 1 - 3 bar range. My 0 - 1 bar output would need to be 0 - 3 volts, while 3 - 4 volts would be 1 - 2 bar, and 4 - 5 volts would be 2 - 3 bar. I think that would work. Too bad we can't reformulate the lookup function in the ECM. . .

Seems to me that the VE changes very rapidly around 50 - 60 kPa in the 1500 - 3000 rpm range. But, once you get over about 80 kPa on up toe 300 kPa, the changes aren't much, so you dont' need much resolution there. I could probably just stick one number in the table from 100 kPa on up and it run just fine.

Mike

It should be possible to come up with a non-linear amp circuit that works similar to what you're describing. I'll let you know if I come up with a way to do that. Like you said, it would be nice if the PCM functions could be modified instead, it would be a lot easier.

If the pcm could be changed it would be a lot easier for everything... You could extend the tables and a few other things... Some guy did it... but he never released the code.. He is Ken from hp tuners.

I have an update to how the Stock PCM reacts to 2 Bar tune...

While I still dont see any real negative side affects from using the 2 bar setup on the LT1 PCM (still looking but I dont see any problems yet) I would like to better understand how the Baro affects the tune (more specifically if it affects timing or overall rich/lean).

What I discovered today from stating at my datalogs was this:
1) The baro value is logged at key on (this was allready known)
2) The baro on LT1 is also reset at WOT, each and every time - what this does is take a new baro reading when WOT is acheived, but so far only under 3700rpm on mine... if your using a 2 bar tune and key on gives you ~50kpa, when you go WOT under boost I notice under certain conditions the baro will climb with the manifold MAP reading for a short period... on mine the Baro stops at about 3700rpm which is about 65kpa, however the MAP reading climbs to ~75kpa at redline as it's reading boost/manifold pressure which is approx 7psi on my setup.

This 65KPA Baro will stay there until the next WOT, which if Im under 2-3000rpm it will read whatever manifold pressure is, usually around 50-60kpa, and if kept WOT again the reading will again climb to about 65kpa and stop climing around 3700rpm.

My fueling doesnt seem to be affected, obviously this was my first concern but everything appears to be consistent from run to run. I was thinking the only problem this could/would affect would be cruise fueling since that's the only time the baro readings might vary depending what manifold pressure was the last time WOT was entered.

I do see consistend Baro increase from run to run up to 3700rpm where it stops climbing, which Im assuming if I were to run up to 100kpa the baro would still stay at 65kpa or whatever it was reading at 3700rpm.

Things I still need to prove out:
1) What affect a changing baro has on fueling - mainly for cruise since the boost/WOT area is consistent from run to run
2) How exactly the Baro system works... if in fact it stops at 3700rpm each time regardless of anything else... my thought on this is they did that on purpose to allow accurate Baro readings since below 3700rpm and WOT gives you low relative manifold airflow, which gives you near actual Baro readings since higher RPM (redline) on stock LT1 usually begins to build slight manifold vacuum due to the restrictions caused by the TB, MAF, intake air filter, etc.
3) What affect would running 15psi have on this since at 3700 the Baro may reach 75kpa by 3700rpm, which then could affect cruise fueling (probably making it a little richer? not sure) until the next low RPM WOT reset the Baro to near actual.

I havent seen any weirdness but I'm also only at 7psi. Anybody using this on higher boost please update!! mainly What effect having artifically high Baro during cruise AFTER a WOT run, compared to normal cruise after Key On but before WOT. To reset the Baro after a WOT run simply put in high gear (low RPM) and go WOT... the Baro should reset. I would expect a change in the fueling corrections but If that's the only side affect and it doesnt affect cruise driveability then I still think it's a valid solution to spending $3500 on FAST.

paging engineermike, he's running more than 7lbs. :)

I'm here. However, I don't have anything to add yet.

As I was leaning out the cruise and idle AFR's, I noticed that my initial startup AFR (<2 minutes) was going too lean and started affecting driveability. I then starting looking closer at the tune and noticed that there were some odd values in the "Initial Startup AFR enrichment Vs. Coolant Temp" table that had it actually adding fuel once the engine came up to temperature. That explains the problem I was having.

I decided that I'm going to put in the correct 42 lb injector constant instead of the 30 that dookie liked for 84 lb injectors. That will require starting over on the VE and start up fuel tables. I guess I'm OCD like that, but I had to start over on the VE table anyway since I fixed the startup enrichment table.

Mike

bump, i love this thread

Yes, this is a good thread. Keep the info coming.

Well I've been driving with the tune and still havent seen any problems... I still have to compare KEY ON BARO of ~52kpa then entering WOT above 3700rpms and see if the BARO resets to manifold vacuum (previously discussed the BARO resetting at WOT only below 3700rpm I saw recently)... but so far no problems with 7psi and under.

Im curious what will happen with a 14psi setup - this may increase the BARO so much that afterwards idle fueling will be noticably rich for cruise.. but this needs to be proved out.
More importantly if KEY ON gives 52KPA and anything over 3700 doesnt reset the BARO then if you enter WOT above 3700 will the BARO stay at 52kpa vs entering WOT at 2000rpm which for me is showing resetting the BARO up to 3700rpm (matching the manifold pressure)... if you generate considerable boost below 3700rpm then what affect would these two "ENTERING WOT MODES" do to actual AFR at WOT (if one WOT run the baro shows 52kpa vs the second WOT run shows ~65+kpa).

Really, what affect on fueling does BARO have? I think it's safe to say SO FAR 7psi and under works very good.

Someone posted a question about needing a 3bar for 15psi, I dont think so since you should be able to use the PE vs RPM tables for VE MAP ranges above 100kpa.

I do fully plan on running the 2 bar map setup and will tune it myself. I'm going to start with engineermike's tune probably(Hi Mike, I need to get an email to you) though just to make the initial startup tune good. I'll be datalogging and tuning to 15lbs for the street, and then hoping to run 18-20lbs at the shootout.

subscribing

Hey if possible could you send me a copy of your 2 bar tune?
I thought about taking advantage of the OBD2 PCM's T side 28f010 flash chip.
It's 128K but only 96K is used so you still have a blank 32K area.
Why not patch a file and create new tables in the unused area.
I got this idea from looking at Motorola AN432 that describes 128K addressing for the HC11.

Sure, send me an email address to send to.

This is a little off topic.. but "Why not patch a file and create new tables in the unused area." Im a bit confused though, if you can do all that patching and what not, why do you need my tune? If you can patch and create new tables then there's no need for my tune since it's for a mucked up 2 bar on stock 1bar PCM.

Let us know, thanks

I can't but I'm trying to learn. I've had some free time recently and have been doing some reading.
I was thinking that it would be easier to tell the pcm to jump to some extened table in an unused spot instead of trying to move too many things around in the file.
There is plenty that I don't understand. I'll keep playing with things and maybe I'll get somewhere.
My email is cbeerman@optonline.net

Could I also get a copy of your tune? In the next month or so I'll be ready to try this out and I think with the E85 I'll be running this might be a good way to take advantage of the ability to tune the timing while in boost.
Thanks,
Dave
Guitarman03@Charter.net

I've been thinking about another "trick" to try on the stock PCM when referencing boost. This is complicated but this may just be the trick for the one "problem" I've noticed with a 2 bar on a LT1 PCM. (the BARO reading). Also, I will test all this soon as snow/salt is off the roads.

This is a slighly different thought I had related to the BARO reading that I havent thought of before which I've been thinking about alot lately... Earlier in this discussion I posted results from one of my datamaster logs because I noticed the BARO resets at WOT under 3700rpm each time (not just at key on like the older TBI PCMs and others). For 6-7psi I dont see a problem so far.. however at 15psi Im wondering what will happen. I'd like to get this straightened out before switching pullies for 15psi.

Recap.. I start the car with my 2-bar and the Baro will stay at ~50kpa until I go WOT under 3700rpm.. now with boost in the intake I see the Baro increase to ~63kpa at 3700rpm then it stops there, doesnt increase anymore as RPM and MAP reading climbs to ~75kpa. This happens time after time when WOT entered below 3700rpm (BARO stops climbing at 3700rpm each time).

Now, this leaves the big question in my mind... if I setup fueling for BARO of 63kpa all the way to redline like I would do on a dyno or rolling from 30-50mph (starting WOT below 3700rpm) I get consistent AFR's. My questions is what would happen if I start the car, let it warm up, then lay into WOT for the first time at 90mph starting from 5000rpm (like when that new Z06 pulls up next to you and you have to start pulling where the powers's at)... well if the BARO stops climbing at 3700rpm at WOT, what if I enter WOT above 3700 without previously running WOT below and thru 3700rpms Im thinking the BARO could possibly stay at 50kpa during this 5000+RPM WOT run... and this could mean fueling could be :alert: LEAN :alert: (since less atmosphere pressure means less airflow into cyl, meaning less fuel is needed). This could potentially be bad.

Now if the above BARO info is true which I think it is I could simply:
1) Make sure I make one WOT pull thru 3700rpm to reset BARO to ~63kpa and problem solved.. or
2) never make a WOT pull below 3700rpm (this is what I need to verify - see if the BARO stays at 50kpa if I enter WOT above 3700rpm after starting the car)
3) Setup fueling so the car wont be lean if I enter WOT above 3700rpm for first time (making 50kpa Baro) meaning if I do enter WOT below 3700rpm the fueling will be on the rich side until I enter WOT at like 1500rpms to reset BARO back to ~50kpa - but I really need to measure how much AFR is affected by this and if the BARO will in fact stay at 50kpa if I enter WOT above 3700rpms. At 6-7psi I havent noticed a a problem so far but I also have not compared Wideband readings between a WOT run with 50kpa BARO and WOT with 63kpa baro.

If this is all true then I would expect siginificant AFR changes especially at 15psi (because at 3700rpms the BARO could freeze much higher like 70-75kpa) then this could make a considerable amount of difference with fueling between 50kpa and 75kpa BARO (or method of entering WOT)... in the worst case it could be lean (if entering WOT for the first time above 3700rpms unless fueling was setup for it then it would be rich as worse case if entering WOT below 3700rpm).

Anyway.... with all that said.. my thought on how to avoid any of this from happening (different BARO readings above 3700rpm depending when you entered WOT) is something like this:
1) Disable Closed Loop and run purley SD in open Loop (to stop fueling correction) and allow fueling control strictly from the VE tables... BARO will still be affected without help from the next step,
2) Disable PE (WOT) mode totally somehow (%TPS for WOT = only 99%) and run purely off of the VE tables (my PE enrichement is set to 0 anyway).. since hopefully you will always be out of "PE/WOT" (assuming you could turn that off completely) the BARO should never reset until the next Key On which is perfect. The alternative would be entering 0% TPS for WOT but then the BARO will constantly reset and hold whatever MAP was seen at 3700rpm.

Anybody with serious thoughts on this please chim in! Anybody running 0% PE mode at WOT please chim in since you could say how to do that?

And yes, if we could modify the PCM or add any one of these controls to LT1_Edit OR Tunercats this could really fix all the problems
1) Lock BARO to reset only at Key On and not at WOT (like older PCMs)
2) Completely disable entering PE/WOT MODE (99% TPS is all I see)
3) Enable 2 bar MAP (obviously) (this would automatically mean the Baro would be locked to Key On only OR a seperate sensor would be used for Baro readings)

I'll be running only in open loop so I don't think this will affect me, hopefully you can figure something out.

two stage boost controller and a window switch ? :shrug: :p

side note: i know nitrous shouldnt be engaged until over 3k rpm since the cyl pressures would get too high etc etc etc. does that still hold true for boost? Im gonna be boosting a stock motor, would it be safer to run it at 5-6 lbs up until say 4500 then let a window switch and two stage controller stab it to 8-9 psi for the 4500-redline?

does that still hold true for boost?

No, in fact the stock Turbo Regals would hit peak boost and torque at 2400 rpm.

Mike

2) Completely disable entering PE/WOT MODE (99% TPS is all I see)


I think that's our best bet. Have you tried it to see if it works?

Mike

no I havent tried this yet, next week the weather looks like ~40+ so I'll start driving again then.

First thing I plan to do is run WOT above 4000rpm and see if the BARO increases then I'll go from there.

Are you saying that if the MAP sees 100KPA at key on it will reset below 3700 rpm at WOT anyway? Because we can easily get the Baro to read 100KPA at key on and since it's the highest number maybe it will choose to see that as the max. simply wire in another MAP sensor inline 1 bar map with a switch or relay it at start up so that for a split moment the PCM reads the 1 bar map and than back to 2 bar, you can have it so that as soon as key is on it reads 1 bar map, than when fuel is primed/car turned on, it reads 2 bar map.

Bunker, yes, Im saying the LT1 pcm resets BARO anytime WOT occurs under 3700rpm. You have a very good point with making key on 100kpa I didnt think about that, but keeping that # will be the tricky part since next time you go WOT under 3700 it will reset - this part is proven in my datalogs... the baro resets each time WOT is seen under 3700..
for example:
1) If you start car and drive normal the Baro = ~51kpa
2) If you rev to 2000rpm then floor it and hold to redline then baro climbs as the MAP climbs to about 3700rpm then the BARO holds the MAP value (which I think is around 62kpa)... and the MAP value keeps climbing to about ~75
3) Once you let off and drive normal again you see the BARO still at 62kpa under the same driving conditions as it just was before the WOT run of ~51kpa.
4) If you enter WOT again at 2000rpm then you see the BARO resets and starts climbing again with MAP to 3700 then holds... same as the run before it.
What I want to see is what happens if you start the car then rev lightly to 4000rpm, then enter WOT for the first time... will the BARO stay at ~52kpa? I think it will this will be my only concern with the 2bar tune... how this affects fueling.. .if it's not that big of change then I can simply tune for it.. but if you run 15psi then it might have a large affect on fueling.

Most other GM PCM's at least older than the LT1 simply log the BARO at key on and that's it... resetting the BARO under 3700 and WOT makes sense simply because you wont have much if any "vacuum" in the intake so it's a good time to get an atmospheric pressure reading for those who are regularly entering WOT/PE. Once you pass 3700rpm you have potential to build manifold vacuum and makes sense why the BARO reset would be limited to 3700rpm. Good for them.. not for us... Im sure LT1_Edit or Tunercats could easily enable changes to this parameter but im sure they never thought to invest the time... I would pay pretty good change for this one single option (disable BARO reset), and pay even more for full 2 bar support (obviosly not as easy to enable). I am sending an email to each company right now... at least possibility to disable BARO reset... I suggest anyone reading this do the same... if they get requests from a few people they might actually look into it.

... Im sure LT1_Edit or Tunercats could easily enable changes to this parameter but im sure they never thought to invest the time... I would pay pretty good change for this one single option (disable BARO reset), and pay even more for full 2 bar support (obviosly not as easy to enable). I am sending an email to each company right now... at least possibility to disable BARO reset... I suggest anyone reading this do the same... if they get requests from a few people they might actually look into it.

Good idea. :thumb:

Thanks for the info, with 15lb of boost it may also help though since by 3700rpm the boost will may be very close to 15psi though :) dunno exactly haven't floored it like that yet. However, with regards to having the option with Tunercar, I can tell you right now that LT1_Edit will probably not release anything, but Tunercat will, my friend has sent them many things in the past and they worked with him to put a lot of the features on. One feature is the Closed Loop Timer control recently added by Tunercat, that was a request, he sent them two files, one where he noticed closed loop happened earlier and the other later, and within a few days they sent him a definition file :)

So I'll send them an email aswell, they may be able to find it and give it to us as Tunercat still constantly updates their definition files for tunercat.

Just sent them an email.

IT WORKS!! BARO resetting is stopped. LT1_Edit did it for me as a test, then TunerCat investigated it and sent me a new definition file. LT1 Edit also changed the Throttle threshhold to 100% whereas Tunercat is only adding the RPM threshold...

"Hi Dan,

Thank you for your e-mail. We've added the 'Baro Update RPM Threshold' constant to the $EE ECM Definition File. I took a quick look at the code for the $EE and it appears that if the RPM is greater than the RPM value specified by this parameter the baro update is skipped so this parameter to 0 to should disable the baro update at WOT."

I tested it and it works... the one thing this means is fueling has to be increased ALOT... Im getting some knock from it due to leanness but I've been increasing the VE and the PEvsRPM some and it's getting better. It's very worth it because this means consistency each time. With baro reset enabled you could possibly blow up your motor under the worse case imaginable.


A major step forward here!! This should be 100% reliable now.

One other thing Im talking to LT1 Edit is something about re-scaling the MAP tables so 100kpa = 100kpa using a 2bar tune... not sure exactly what he meant but sounded like a partial 2-bar support.. anything helps!

This is good news. I'd be willing to pay for the LT1_edit update if they can get it worked out.

Yup I also got the email just today with the updated EE, told ya Tunercat will come through right away :)

So now we just set it to 0 and way we go :) Sooo happy.

Can I get the updated tunercat file! :)

skinniesvideos at gmail.com

Yea this is good news! The BARO reset has been the only problem all this time.

In related news, I decided to lower my injector flow rating even more (27lb/hr from 30lb/hr) to help richen up boosted fuel since I'm getting near 100% in the VE's... (~84% in the ~75kpa load range or ~7psi).. Did this to give me some room when I go to 15psi. I only have about "2" in the PE vs RPM as well. THis seems to work good but I wont have real results until I get my Wideband sensor working again (timing error).

Can i nominate this thread for a sticky. Ive learned a ton about tuning and scaling.

Nice.

So this constant only stops the re-calibration at 3500 (~WOT) conditions right?

there still needs to be a way to fix the start-up calibration? or are you just planning on scaling the PE tables or injector constants to compensate?... hense the talk above about re-mapping (excuse the pun ;)) the tables beyond 100kpa.

Also, anyone have a link to the new C.A.T.S. definition file? I just checked their site and didn't see a new update on there (is this a email-only update?).

Kudo's to TunerCAT for finding the constant... turbo's are sounding more and more friendly.

No you set the Baro reset to 0 meaning it only logs at start up which is perfectly fine because it will not change while driving and atmospheric changes are insignificant at key start up to make any impact on our tuning, once logged at start up at 54KPA (2bar) it will always stay there, I confirmed this as well, that was the happiest email when I emailed them the night before and got one back the next day with the update :) They've done this for me and a friend in the past, my friend emailed them a few month back to find the closed loop timer table, within a few days they found it and it's now in tunercat as well.

Have you heard anything from the LT1_edit guys at carputing?

If possible I would hold off emailing Tunercat or LT1_Edit since today they are looking into re-scaling the MAP tables from 25-100 with resolution of 5 to 50-200 with resolution of 10. This DOES NOT mean full 2-bar support this just means 7psu should be about 150kpa in the editor instead of ~75kpa the way it is done right now. I dont know how it will show up in Datamaster.

"So this constant only stops the re-calibration at 3500 (~WOT) conditions right? " Yes and no, stock the PCM resets BARO all the way from 0-3600rpm at WOT (or over about 36%TPS (or close). Changing it to say 500rpm completly stops BARO reset at any rpm/load/boost other than intial Key On and below 500rpm (like older GM's used to do). You could enable 1000rpm limit that way if you lug it and WOT you get a baro reset - this would be helpful when driving low to high altitude in the mountains - RPM is low enough were boost shouldnt be affecting the actual BARO reading.

They are quick and very helpful Im suprised of the amount of support on this one.. I think I may have helped them nail down one of the problems with running 2bar MAPs on LT1's and that is why they are helping? I dunno. Ever since I emailed them with detailed description of the problem they seemed to say they searched the code and found what I was talking about and have found ways to make it work better.

Right now LT1_Edit is modifying my file for me, sending it back and I test it. Tunercat sent me updated definition file to test. Both work.
Now waiting to see if they can rescale the MAP columns and what affect it has in Datamaster or on fueling. Sounds like it wont affect anything other than labeling... would be worth it if Datamaster reports the same scale, if not it would be very confusing.

I fully expect to pay for updated LT1_Edit and Tunercat if the features become available, should be very cheap and give these guys the motivation to keep helping!
Tunercat did say adding tables for complete full bar support would be difficult (didnt say impossible).

For sure, all I know it's so much better now with this definition file, as soon as I got it I tested it out and it was a big relief :)

If possible I would hold off emailing Tunercat or LT1_Edit since today they are looking into re-scaling the MAP tables from 25-100 with resolution of 5 to 50-200 with resolution of 10. This DOES NOT mean full 2-bar support this just means 7psu should be about 150kpa in the editor instead of ~75kpa the way it is done right now. I dont know how it will show up in Datamaster.
is that really doing anything but making it look correct? is the computer actually going to know what those numbers are... is it going to see 100kpa as 0 vacume or 200?
just not sure if your still going to have to scale the rest of the tables up to compensate.



thats really cool that they are working with you on this. hopefully this will make it easier for the rest of us down the road :bow:

Heck after eight years we have it!

Fixed another problem with my huge injectors having rich idle and very rich decel (just above the limit of Decel Fuel Cut Off)...Plus there was this nasty surge upon injector re-light since injectors were over fueling.. I compensated with reduced timing upon re-lite but now the problem is gone... the right way. In Tunercats the stocker shows minimum pulsewidth set at 1.4mS, On slight decel and idle mine was 1-1.3 depending... changed it to just below what I saw requested in Datamaster and all fixed... hold 14.7 on decel and 14.7 on idle. Pretty amazing control that stock PCM has I think.

Sent you a pm with a few questions, so far my car doesn't like the 2 bar setup yet.

Sent you a pm with a few questions, so far my car doesn't like the 2 bar setup yet.

Yea, I would expect that. There's so much stuff I've changed as the result of my 83lb injectors not reacting like they should.. or not reacting like some people say they did for them. I dont know if it's the AEM injector driver or the brand of Injector but I had such bad lean tip in stumble with the "correct" settings I was about ready to sell the 83's and go back to 42's and attempt a FMU and huge pumps.

I've got my Injector Flow entered as 27lb/hr now and it is SO perfect I almost cant believe it. My LTerms are only 1# apart and my idle so far is also 0-1# apart. I really cant believe it. Time will tell on this one seems too good to be true.

Basically Before with the resettig BARO your BLMS were always moving around depenging how long after startup you floored it for the first time... damn that was really a messed up tune looking back. ha... problaby why my BLMs are so good cause I triple sealed the exhaust.. built an extention pipe in the TB to INTAKE IAC passages... etc.

Glad that's over.

Just received moments ago from Tunercat:

"I've set up this version of the Definition File for the 2 bar MAP sensor. You'll find that all the MAP parameters have doubled and the MAP scales on MAP indexed tables have been modified accordingly. I've modified the cylinder volume parameter scaling to adjust the speed density fuel calculation to adjust for the 2 bar MAP sensor so you'll have to reset this value to the correct value. After resetting the cylinder volume you should be able to reset the injector flow rate to the correct value for your injectors.

I'm a bit confused though why you previously had to halve the injector flow rate and the VE values as these changes would counteract each other. Try out the modified Definition File and let me know how it works out."

Just received moments ago from Tunercat:

"I've set up this version of the Definition File for the 2 bar MAP sensor. You'll find that all the MAP parameters have doubled and the MAP scales on MAP indexed tables have been modified accordingly. I've modified the cylinder volume parameter scaling to adjust the speed density fuel calculation to adjust for the 2 bar MAP sensor so you'll have to reset this value to the correct value. After resetting the cylinder volume you should be able to reset the injector flow rate to the correct value for your injectors.

I'm a bit confused though why you previously had to halve the injector flow rate and the VE values as these changes would counteract each other. Try out the modified Definition File and let me know how it works out."

So does this mean the VE tables won't only be 17 columns wide anymore, but now 34? :eek: Please tell me so and I need that definition file asap from tunercat if so. :bow:

This is getting better by the day!!!!! woot

So does this mean the VE tables won't only be 17 columns wide anymore, but now 34? :eek: Please tell me so and I need that definition file asap from tunercat if so. :bow:

No, same resolution just changed the labeling. He also made other changes so all MAP values should be right but these changes are only in the definition file... not the PCM file (at least I dont think so).

Because of this I dont think logging software will display the updated values so really it would make tuning harder since the logging software will report 1/2 the value as the TUnercat menus.

I would be excited for the BARO reset since that's the only problem holding us back all this time and it's been fixed.. there's enough resolution for a 2bar.. probably not enough for a 3bar.

Once I have time to confirm the logging vs the Tunercat updated I'll post but Im pretty sure that's the case.

I'm looking at it as well, it definitely won't change what the PCM reports, it can't do that, its for our eyes only which is fine, it helps in some ways, now we just need a VE master that tunes only up to 50 kpa, that would be ultimate :)

Since the 2bar definition file doesnt report the same scale as the logging program I decided not to even use it since (in my opinion) there's no point reading two different scales when you can read the same scale.

I'm stickingn with the BARO RESET and that's it. My AFR's are consistent from run to run and no other problems to mention.

Thanks to Tunercat and LT1_Edit we have a reliable tuning option using the stock PCM.

Since the 2bar definition file doesnt report the same scale as the logging program I decided not to even use it since (in my opinion) there's no point reading two different scales when you can read the same scale.

I'm stickingn with the BARO RESET and that's it. My AFR's are consistent from run to run and no other problems to mention.

Thanks to Tunercat and LT1_Edit we have a reliable tuning option using the stock PCM.
I was thinking that exact same thing, if they just changed the numbers at the top of the table, then I wouldn't want to use that either.

I'm looking at it as well, it definitely won't change what the PCM reports, it can't do that, its for our eyes only which is fine, it helps in some ways, now we just need a VE master that tunes only up to 50 kpa, that would be ultimate :)

I run VE Master then I copy all the original tables over 55kpa from the pre-VEMastered file... whoala!

Since we're on a roll lets see if we can get Datamaster AND VEMaster to change the MAP scales to match the 2Bar Def file? Just kidding... Im plenty happy as it is and there's no real improvement from attempting that so screw it.

Ahh yes very good idea to just copy 50kpa+ from pre-ve master :)

I got the 2 bar setup running now, still tuning on it, but it runs and drives. I'm having the same issue engineer mike has where it leans out at 27kpa at light throttle, even though when it hits 25kpa or 30kpa it gets rich again. Anybody else having this issue or have a fix to it? It's VERY annoying, that is the only spot it will lean out like crazy.(from 12.5 to 17.5)

wow, i havent checked on this thread in like a month, good work guys.

Im going to get ahol of tunercat and get the updated definition files both pre and post 2bar.

Dookie, I may need to get a copy of your tune to get started. Unlike you guys, We've had snow on the ground for the past 6 months, so tuning hasnt been happening

I got the 2 bar setup running now, still tuning on it, but it runs and drives. I'm having the same issue engineer mike has where it leans out at 27kpa at light throttle, even though when it hits 25kpa or 30kpa it gets rich again. Anybody else having this issue or have a fix to it? It's VERY annoying, that is the only spot it will lean out like crazy.(from 12.5 to 17.5)


Possible could be a resolution thing... I mean if BLMs in one cell are rich then it could be subtracting, then a little more throttle MAP changes but BLMs could be in same cell... then it starts doing just the oppposite... adding fuel.. so the overall average comes out the same.

I have not noticed that problem yet. One thing I just did recently was (again in Tunercat) lower (half) the BLM update hystresis.. or someting like that. That value went from 2 to 1. Something I should have done in the beginning.

One other thing I was playing with was minimum injector PW... was set at 1.4ms, with bigger injectors this needs to be modified... lowered it to 0.4 and no more richness on decel which could severly throw off BLM's...(BLM picking up rich decel so keeps leaning out LTerms... then once throttle is applied the same cell is severly lean..). Seen that a few times.

Dookie, I may need to get a copy of your tune to get started. Unlike you guys, We've had snow on the ground for the past 6 months, so tuning hasnt been happening

Hmm, far as I know Motor City is SOUTH of Auburn Hills...

I'm still in open loop like Mike, so BLM's don't matter at all. Here is how it is on my car right this second...

25kpa from 1000 to say 2500....12.0-12.5 afr
30kpa from 1000 to say 2500....12.0-12.5 afr
27kpa from 1000 to say 2500....17.5-19.0 afr

So anytime I'm cruising and hit that 27kpa(which is A LOT) then it leans it out badly, causes it to cut out and make the car sound like a big cam car.

I'm going to try going in the AFR coolant temp vs map table and adding 10 percent to that table in the 25 and 30 kpa cells, then pull the 10% back out in the VE table to see if that changes anything.

Anybody have any other ideas?

I should mention the entire rest of the tune is fine, doesn't lean out except in that one spot.

So anytime I'm cruising and hit that 27kpa(which is A LOT) then it leans it out badly, causes it to cut out and make the car sound like a big cam car.
[/QUOTE]

Is it always between those RPM? The entire 1000-2500 RPM band? As long as MAP is 27kpa regardless of TPS? Is Injector PW consistent though the lean? How about timing? If either are not then could be transition effects. Is something like EGR opening there?

I would be interested in seeing datamaster log of the problem area.

25kpa from 1000 to say 2500....12.0-12.5 afr
30kpa from 1000 to say 2500....12.0-12.5 afr
27kpa from 1000 to say 2500....17.5-19.0 afr

I'm having the exact same problem. O2's are disabled and I have no emissions control stuff on my car.

I believe its simply a resolution thing. I also think the stock ECM rounds the MAP reading up or down to the nearest cell in the VE table, rather than using linear interpolation. I have no idea what to do about it other than bandaid by richening up the 25 and 30 kpa cells.

Mike

So anytime I'm cruising and hit that 27kpa(which is A LOT) then it leans it out badly, causes it to cut out and make the car sound like a big cam car.


Is it always between those RPM? The entire 1000-2500 RPM band? As long as MAP is 27kpa regardless of TPS? Is Injector PW consistent though the lean? How about timing? If either are not then could be transition effects. Is something like EGR opening there?

I would be interested in seeing datamaster log of the problem area.
I'd have to look at the logs, obviously above 2500rpm I'm pulling more kpa than 27 so I don't know if it affects the higher rpm. I haven't got to do much datalogging yet, I have a few things to try though. Injector PW goes lower, the computer IS commanding leaner. Timing isn't changing or freaking out drastically at all. I don't have EGR or any emissions on my car at all.

If the open loop AFR trick doens't work, I'm going to try to band aid fix it via PE, set it to go into PE at 25kpa(or maybe 27kpa), then add fuel in my VE tables. I'll add around 12% fuel in PE up to 2500rpm. I hope I don't have to fix it this way, but if I do, it will have to be done. I'd rather it run high 14's in that lean spot(27kpa), then hit high 11's in the cells around it...vs...doing like it is now where it goes 17-18 afr in the lean spot.

Hmm, far as I know Motor City is SOUTH of Auburn Hills...You live in Auburn Hills? I am in Royal Oak! We should go cruisin sometime. I live right near woodward, and shame on you for driving a nice fbody on these crappy salty roads

is it doing that when your in the throttle or off?
might want to check the deceleration fuel cut off map settings


http://www.mofbody.com/blkchevyz/map.jpg

is it doing that when your in the throttle or off?
might want to check the deceleration fuel cut off map settings


http://www.mofbody.com/blkchevyz/map.jpg
I actually changed that in this tune also, because it is at 27kpa, but it happens on the gas not off the gas so I doubt this will make much difference.

maybe it doesnt reference the tps sensor since that would be a decent amount of vacume and just assumes your not in the throttle... thats probably just wishfull thinking though.

maybe it doesnt reference the tps sensor since that would be a decent amount of vacume and just assumes your not in the throttle... thats probably just wishfull thinking though.
I'm hoping it is a miracle and fixes it, but not holding my breath. I won't know until Thursday or Friday, the transmission is out of my car right now.:(

You live in Auburn Hills? I am in Royal Oak! We should go cruisin sometime. I live right near woodward, and shame on you for driving a nice fbody on these crappy salty roads

Well I only drive it when the roads are dry and the salt is worn off... which is not very much. Tomorrow it's suppose to rain all day.. that means clean roads unless it gets cold again.

maybe it doesnt reference the tps sensor since that would be a decent amount of vacume and just assumes your not in the throttle... thats probably just wishfull thinking though.

I see a correlation between no 02's and a tuning problem. There's also a whole lot of guessing a Datamaster log could straigten out.
Looking at my logs.. I see 27kpa rarely. My log shows my having 27kpa cruising at 74mph with 2% Throttle and 1625rpm, and maybe the next lower gear while slightly accelling... 10%tps. I dont see a problem yet.

What was the reason for going completely open loop again? Possible to re-connect 02's? Tunercat has a setting to disable Closed Loop under a certain MPH as well.

If you've seen pics of my engine by and how clean it is, you'll undestand why I don't want to add o2 sensors back to it. All the wiring is gone for them, no way they can go back on my car. I prefer to commant what AFR I want, not let the computer do it.

I should know by the end of weekend a fix for this issue for those who want to keep the open loop tuning.

With my stall, gear, tires, etc, anytime I'm cruising around 35-50mph I hit the 27kpa cell a lot. I also it it when I come off a stop light about 5 feet out.

can you even use the o2 if your halfing the injector flow rate? i think the computer would just be over compensating.
or did you get away from that?

If you've seen pics of my engine by and how clean it is, you'll undestand why I don't want to add o2 sensors back to it. All the wiring is gone for them, no way they can go back on my car. I prefer to commant what AFR I want, not let the computer do it.

I should know by the end of weekend a fix for this issue for those who want to keep the open loop tuning.

With my stall, gear, tires, etc, anytime I'm cruising around 35-50mph I hit the 27kpa cell a lot. I also it it when I come off a stop light about 5 feet out.

Eek. Mind sharing your setup so I can avoid it? haha j/k =p

Still works good down the strip im sure. Please keep us updated if you find a fix.

can you even use the o2 if your halfing the injector flow rate? i think the computer would just be over compensating.
or did you get away from that?

Well obviously you can becouse dookie is doing just that. MORE than just halfing the rate.

can you even use the o2 if your halfing the injector flow rate? i think the computer would just be over compensating.
or did you get away from that?


Yea I have closed loop with a decent cam 230/234 and it seems to work pretty good... no different from when I ran the 1 bar. When I ran the 1bar at one point I disabled idle closed loop (using speedo in TUnercar instead of anything else) and that worked good for whatever I was doing... now with the 2bar I re-enabled idle closed loop and it still seems to be ok.

I do have my injector flow way down (partly to fix lean tip in stumble using 83lb injectors) from what I understand the other way to compensate using the 2bar would be using the Cylinder volume? Not positive though.. either way the same result is achieved.

"1982z28with18s" - I see you have the stock cam.. that will make all the tables shift compared to what I see... that explains the difference.
I think the reason I didnt loose any driveability was because for whatever reason (and may be due to the cam) the values in my range of idle-cruise-mild load were maybe less curvy than what the stock cam needs... I know this is true with the timing curves but not sure about the VE tables... (I increased timing alot compared to stock in low rpm/load which essentially smoothed out the graph.. eliminating the need for extra tables there since some cells are so close to adjacent cells).

If you've seen pics of my engine by and how clean it is, you'll undestand why I don't want to add o2 sensors back to it. All the wiring is gone for them, no way they can go back on my car. I prefer to commant what AFR I want, not let the computer do it.
.

Do you have a Wideband like LM1? Now might be a good time to test the "simulate narrow band 02" output function.. I've been wanting to try this forever... I posted about it a while back.. I think it could potentially be a perfect solution for those with big cams and split BLMs.. as long as the computer accepts the signals and allow's closed loop.. you woud have to wire in both sides from the same signal but it might just work.. plus you might be able to log the AFR using the stock 02 pcm inputs in datamaster. Tunercat has some settings for 02's I dont know what they mean.. something about ranges. Might be do-able.

I don't have the stock heads/cam anymore, they came off this winter. It's a small xfi cam now with some Lloyd Elliot heads.

I have the lc1, not lm1, and I already have it wired into my pcm so it shows up in datamaster via the ac pressure like others have done in the past.

I'll know more in a few days when I get the car back on the ground with the transmission. The ONLY driveability problem I have is the 27kpa spot, all other spots are fine.

I have the lc1, not lm1, and I already have it wired into my pcm so it shows up in datamaster via the ac pressure like others have done in the past.


I did some homework for you...
http://www.turbododge.com/forums/f4/f21/159996-lc-1-xd-16-analog-signal.html
"My LC-1 has two analog (narrow band) outputs. It says that one can be hooked up to simulate the stock narrow band O2 sensor. It also goes on to say that some computers need the stock O2 sensors heating element hooked up and working or it will give the computer bad signals. It says to just hook it up and secure it somewhere."

I know all about that AC pressure input that's not what I was referring too... if you could.. hook it up to your O2 sensor PCM inputs and see what happens. It's ok having AC pressure input.. but would real "data capture", " or even better... "averaged bank to bank 02 circut/logging/fuel adjustment be better? Since your not using the 02 input's there really no reason not to try it.

Havent read about anybody doing it yet.. I posted about it just never tried it. Had a bunch of people theorize about how it wouldnt work but that was opposite of the point of trying it (those guys never tried it).
Bunch of guys said 2Bar reference wouldnt work for unknown reasons... those reasons were discovered to be BARO RESET.. we overcame that pretty quick once discovered now didnt we. Again, Tunercat has settings for O2's.. (specific voltage references...). I can only imagine that's for "non stock" 02 action.

My setup:

383 15lb boost, 226/236 cam on 114lsa, 9:1 compression or so, me and Dookie454 were playing around the same time with ours, I have no problems at all, no lean spots with 02 sensors in 27map range.

Like said, make sure you lower your MIN injector PW to around .5 or so which is what I did, you'll also notice that if you ever hit lower than 1.4ms which is stock MIN, your BLM will flatten at 128blm, when I first noticed it thats when I changed the MIN PW to .9 than to .5.

Also look at all map tables, update hyst to 1 instead of 2 ofcoarse, and make sure to bring your RPM/BLM map ranges to a usable area, keep 2 bar in mind when doing that as well, you want to look at your logs and see what rpm you spend most the driving at and MAP ranges, than dial it in, remember there are 16 cells total to use.

I also had to bring the injector constant to lower than half to take care of the lean tip in which was fixed after that was done plus lots more VE tunning with VE master.

But basically no problems what so ever here running 15lb boost, good through all RPM range, you can also change your low PW injector adder vs.Base pulse width, look at your logs, as you play with throttle you'll notice that when you tip in, your PW shoots up, but higher RPM free idle = less BPW, so you might want to actually do the opposite of stock, at lower BPW have less adder than at higher BPW, that helps in cleaning up your throttle response and also how well your BLMs settle down when coming to idle.


Also set my PE to come on earlier since with 15lb you hit boost very fast, so 66% TPS b4 PE at lower rpm is too high, by than I'm already at 5lb boost, set that to 50%.

Just takes lots of tweaking around, I spent maybe 20 hours in tunning, but I think everything is pretty much dead on.

Also my setup I just passed the IM 240 emissions test with flying colors :) So guess it runs clean too, just used the FLP stock cats, nothing special, and idle timing at 18*, the rest left it as is cuz I felt thats what the car liked.

I remembered I do notice a little roughness the first time I drive the car after a PCM flash while in open loop. within about 5 minutes of closed loop operation everyting smoothes out.

I think the o2s smooth this right out.. may fill in the gaps between cells so to speak.

My setup:

383 15lb boost, 226/236 cam on 114lsa, 9:1 compression or so, me and Dookie454 were playing around the same time with ours, I have no problems at all, no lean spots with 02 sensors in 27map range.


Thanks for the info bunker! You are running with no Baro Reset right?

...With my stall, gear, tires, etc, anytime I'm cruising around 35-50mph I hit the 27kpa cell a lot. ..

This is exactly my problem. 25 kpa is throttle on but slightly decelerating, while 30 kpa is throttle on and slightly accelerating. To hold constant speed in the 35 - 55 mph range required 27 kpa and it runs 17/1 A/F ratio.

Mike

This is exactly my problem. 25 kpa is throttle on but slightly decelerating, while 30 kpa is throttle on and slightly accelerating. To hold constant speed in the 35 - 55 mph range required 27 kpa and it runs 17/1 A/F ratio.

Mike

And you are also running no 02's? If you can enable them or connect the WB to the stock pcm that may fix it, you can try disabling closed loop under 20mph see if that helps whatever 02 problems you were having.

No probs Dookie454, right I'm running 0 for baro reset.

Also as for Closed loop idle enable mph that is I believe to enable cell 16, so if ou set it to 20mph, that means that anything under 20mph 0% TPS you'll be in cell 16 which is the idle cell, right now I believe you can be in 17 or 18 until you come to a complete stop.

No probs Dookie454, right I'm running 0 for baro reset.

Also as for Closed loop idle enable mph that is I believe to enable cell 16, so if ou set it to 20mph, that means that anything under 20mph 0% TPS you'll be in cell 16 which is the idle cell, right now I believe you can be in 17 or 18 until you come to a complete stop.


Thanks Bunker, I guess that explains why it's set to ~0.7mph stock!

Could I get a copy of the definitions file please? rtracy@stny.rr.com Thanks

I did some homework for you...
http://www.turbododge.com/forums/f4/f21/159996-lc-1-xd-16-analog-signal.html
"My LC-1 has two analog (narrow band) outputs. It says that one can be hooked up to simulate the stock narrow band O2 sensor. It also goes on to say that some computers need the stock O2 sensors heating element hooked up and working or it will give the computer bad signals. It says to just hook it up and secure it somewhere."

I know all about that AC pressure input that's not what I was referring too... if you could.. hook it up to your O2 sensor PCM inputs and see what happens. It's ok having AC pressure input.. but would real "data capture", " or even better... "averaged bank to bank 02 circut/logging/fuel adjustment be better? Since your not using the 02 input's there really no reason not to try it.

Havent read about anybody doing it yet.. I posted about it just never tried it. Had a bunch of people theorize about how it wouldnt work but that was opposite of the point of trying it (those guys never tried it).
Bunch of guys said 2Bar reference wouldnt work for unknown reasons... those reasons were discovered to be BARO RESET.. we overcame that pretty quick once discovered now didnt we. Again, Tunercat has settings for O2's.. (specific voltage references...). I can only imagine that's for "non stock" 02 action.
I might try this when I get more time on my hands.

I got my part throttle tune dialed in fairly well tonight, it does have the lean spot at 27kpa still though, but doesn't surge nearly as bad. I found it likes less timing at idle though with this cam, around 23 degrees seems to be perfect, more and it will want to surge, even if its rich or lean.

I haven't got to test my other ideas on how to fix the issue yet, but honestly right now the car is very driveable, probably has less "surge" than most cammed 6 speed cars ever see.

WOT is nailed in pretty good up to 11lbs, then a lil rich up to 14lbs. I need to get some more better gas in it and will finish tuning it up to 15lbs next weekend and try to hit the track. :)

1982Z28, I think I've figured something out, but my scanner is broke so I can't verify. What do you have your minimum pulse width set to?

Mike

I'll have to check the tune when I get to work, but I believe it was down to 1.09.

I'll have to check the tune when I get to work, but I believe it was down to 1.09.

Make that number about .8 and see if everything at low load doesn't go lean. Then, correct the VE tables to make up for it. I think that will solve our 27 kPa issues.

You see, today, I put in a .8 and test drove my car. I really didn't expect to see any difference except for a slightly leaner idle since my idle PW should be around 1.0, but the minimum was 1.4. What I got was everything lean at light load and terrible surging because of it. I believe the VE tables are not correct (lean) and the minimum PW of 1.4 was masking that by artificially adding fuel. So, 27 kPa is right in the range where the VE table was making it go lean, but drop down to 25 kPa and the PW went to 1.4 and it richened back up.

Its just a theory, as I need to get my scanner and WBO2 back on line before I can test it.

Mike

Make that number about .8 and see if everything at low load doesn't go lean. Then, correct the VE tables to make up for it. I think that will solve our 27 kPa issues.

You see, today, I put in a .8 and test drove my car. I really didn't expect to see any difference except for a slightly leaner idle since my idle PW should be around 1.0, but the minimum was 1.4. What I got was everything lean at light load and terrible surging because of it. I believe the VE tables are not correct (lean) and the minimum PW of 1.4 was masking that by artificially adding fuel. So, 27 kPa is right in the range where the VE table was making it go lean, but drop down to 25 kPa and the PW went to 1.4 and it richened back up.

Mike

I agree with Mike on this, when I had my min pulsewidth too low (0.5) I was getting very lean surge in the transition from decel to very very slight throttle. With the same tune I also had some pretty bad idle surge that would ususally smooth out the longer it idled but tap the throttle and it would start surging again. I increased my min pulsewidth to 1.1 (0.94 was still too low) and it all went away. Tuning the VE's should help, but not sure it will help with the idle surge I was having.
I did lean out the VE's alot in that area trying to get decel leaner and finally realized it was because of the min puslewidth being so high (1.4) and I still havent changed/increased the low VE's because it's running real good. My decel (before fuel cut off) is around 13:1 so Im not too concerned, originally was about 10.5:1... I think this was also messing up BLM's since it was trying to lean it out so much but really had no effect due to the min pulsewidth setting.

Make that number about .8 and see if everything at low load doesn't go lean. Then, correct the VE tables to make up for it. I think that will solve our 27 kPa issues.

You see, today, I put in a .8 and test drove my car. I really didn't expect to see any difference except for a slightly leaner idle since my idle PW should be around 1.0, but the minimum was 1.4. What I got was everything lean at light load and terrible surging because of it. I believe the VE tables are not correct (lean) and the minimum PW of 1.4 was masking that by artificially adding fuel. So, 27 kPa is right in the range where the VE table was making it go lean, but drop down to 25 kPa and the PW went to 1.4 and it richened back up.

Its just a theory, as I need to get my scanner and WBO2 back on line before I can test it.

Mike
I'll give this a try this week, if it doesn't work I still want to try the AFR open loop table and if that doesn't work, use the PE table to try to make it work. Really right now the lean spot isn't bad in my car, MUCH better than before, but it is still noticeable.

You ever figure out the high timing at WOT? Mine won't go any lower than 26 degrees, still can't figure this out. :( My 1 bar map tune was perfect, 16-18 degrees, but this 2 bar tune won't go below 26 degrees no matter what I try to command. I believe you had this problem before with the 1 bar map tune also thus why you pulled timing via the igntion box.

I just wanted to add, and although this might not be too important but to be on the 100% safe side since we're tunning VE and want to improve each time with VE Master I did the following:

1. At operating temp, I make sure I drive the car atleast 4 mins.
2. than pull over on the side and start logging with data master
3. drive as normal for several minutes on HWY/street etc..
4. Pull over, and stop data logging
5. Turn car off
6. Run VE master on the log against your tune

Than repeat steps, make sure after uploading the tune, drive again for 4 mins to get operating temp in and if there are any other after start variables we don't want to have VE master accomodate for, so after 4 mins of uploading tune and driving, pull over, start logging a new file, than when done, pull over, stop logging, than turn off car and run new LOG against newer tune.

Also and I repeat, everytime you run these steps, to be 100% certain, try not to DECEL, when going down a hill just put her in neutral, don't hit PE mode or Decel while making the logs for VE master.

I realize it switches to a different cell but who knows, just don't hit those areas and maybe that will take care of a lot of lean/rich spots which sometimes happen after VE master is done.

...maybe that will take care of a lot of lean/rich spots

The lean problem we are having is at 27 kPa, which is between cells. Mine runs fine at 25 and 30 kPa, but lean between them.

Mike

what kpa are you guys having vemaster modify through?

what kpa are you guys having vemaster modify through?

I use my own hand-built logger that captures A/F ratios and puts them into a table with the same cell limits as the stock VE tables.

Like mentioned it might not be the issue for the lean spike but just a suggestion to a clean log for ve master.

Hey Engineermike, could you share a copy of your hand built logger :)? Thanks if you could just send it to my email bunker@telus.net

Thanks so much.

...Hey Engineermike, could you share a copy of your hand built logger :)?

Actually, it can't be e-mailed. It's a hand-held logger that captures everything in the ECM, plus input from a 3 bar MAP sensor, plus input from a WBO2. Then, it will download into MS Excel so you can graph it. Pretty nifty device, but it was a PITA to build.

Mike

what kpa are you guys having vemaster modify through?

I tune 50kpa and below, non-PE mode rpm/MAP.. anything over ~55kpa is boost and should be in PE mode. Some keep it out of PE mode with slight boost that's probably ok too, in other words VE Master works for you, usually anywhere you want closed loop corrections being made.

You also have to copy the pre-VEmastered 50-100kpa tables from the original file since VEMaster seems to add or subtract the cells it doesnt have data for (50-100kpa) depending on the last MAP cell for each RPM range it had data for (Example - my highest MAP of ~50 at 2400rpm had decreased by original*0.934, so it decreased the rest of the 50-100kpa range as well (blindly)... you dont want that so copy the original non-VE Mastered tables in this area.

Example: Last MAP data at 2400rpm was cell 55kpa, which it calculated 0.934
CELL RPM/MAP----Orig VE--Mult Factor--New Value
cell[2400][50]---- 60.5---- 0.958-------58.2
cell[2400][55]---- 65.6---- 0.934------ 61.3
cell[2400][60]---- 68.4---- 0.934------ 63.7 (this is carry over)
cell[2400][65]---- 71.5---- 0.934------ 66.8 (this is carry over)
cell[2400][70]---- 72.6---- 0.934------ 68 (this is carry over)
cell[2400][75]---- 71.9---- 0.934------ 67.2 (this is carry over)
cell[2400][80]---- 73.8---- 0.934------ 68.7 (this is carry over)
cell[2400][85]---- 76.2---- 0.934------ 71.1 (this is carry over)
cell[2400][90]---- 76.9---- 0.934------ 71.9 (this is carry over)
cell[2400][95]---- 78.9---- 0.934------ 73.8 (this is carry over)
cell[2400][100]--- 82.8---- 0.934------ 77.3 (this is carry over)

Actually, it can't be e-mailed. It's a hand-held logger that captures everything in the ECM, plus input from a 3 bar MAP sensor, plus input from a WBO2. Then, it will download into MS Excel so you can graph it. Pretty nifty device, but it was a PITA to build.

Mike

Mike, dont be difficult. Please email your logger. Thanks

ha, just kidding, but would you mind giving out the schematic? Just curious.. sounds like a pretty handy tool.. much like VEMaster makes closed loop VE tuning easy, your gadget could easysize PE/boost tuning.

Please? Pretty please?

Im still waiting for someone to try the WB02 (LM1) narrow band simulation output... wondering if that will "accurately" output the AFR.. It should be possible since the WB itself knows the actual AFR.. they could have built the software so 450mv = 14.7afr, 950mv = 12.0AFR, 975mv = 11.5afr.. ect... I havent read anyone proving or disproving this...

Im just to lazy to do it myself. I do have two old hacked up 02 sensor harnesses... I should be the one to try it. Maybe when the weather gets little warmer.

I have a nifty device too, hooks up to your AC line, and Wideband, so when i log with Datamaster I can see the AirFuel ratio as well under the AC pressure, so 147psi equals 14.7AFR, 120psi is 12.0 :) pretty nice as I can actually log, had a good friend build it.

Now lets not get carried away and all start comparing our nifty Devices LOL :)

I tune 50kpa and below, non-PE mode rpm/MAP.. anything over ~55kpa is boost and should be in PE mode.
Why in the world would you use PE at all? I found out on the 1 bar tune PE was very bad, because if you lift to pedal it for traction, it leans out. You have full 2 bar capabillity, PE shouldn't be used at all.

Hehe turn off PE mode and get VE master to tune your upper RPM in boost as well, for example:

drive car around and do a few WOT runs here and there, run VE master and set target BLM to 99 instead of 128, 99 is 78% of 128 and 78% of 14.7 AFR is 11.5 AFR for example, than open the bin, take all the tables say 55map and below or 60 whatever and copy/paste from previous tune, leave the uppers the way VE master set them with BLM target at 99blm.

I haven't tried that but should work to a certain extent, o2's aren't wideband but they would be pretty accurate hehe, than the rest you can smooth out with wideband.

I want to try this out, the idea just popped into my head.

Why in the world would you use PE at all? I found out on the 1 bar tune PE was very bad, because if you lift to pedal it for traction, it leans out. You have full 2 bar capabillity, PE shouldn't be used at all.

You have to use PE under load when you run closed loop.. PE refers to Power Enrichment mode... meaning it kicks it out of closed loop fuel trimming (ignores BLMS). All my PE Enrichment values are 0 however I still use PE mode to stop the 02's from pulling fuel under load/boost.. I have too, everybody does unless you dont run closed loop then your basically in PE mode all the time. There's no reason not too... if you dont use PE mode under load you'll be running closed loop BLM referencing.. and the PCM will try to hit 14.7AFR all the time even under boost and that could be bad. All the problems with PE Enrichment Fueling is what drove me to make a 2bar sensor work... I cant imagine running 15psi on a 1bar sensor using PE Enrichment without serious help from an FMU.

Hehe turn off PE mode and get VE master to tune your upper RPM in boost as well, for example:

drive car around and do a few WOT runs here and there, run VE master and set target BLM to 99 instead of 128, 99 is 78% of 128 and 78% of 14.7 AFR is 11.5 AFR for example, than open the bin, take all the tables say 55map and below or 60 whatever and copy/paste from previous tune, leave the uppers the way VE master set them with BLM target at 99blm.

I haven't tried that but should work to a certain extent, o2's aren't wideband but they would be pretty accurate hehe, than the rest you can smooth out with wideband.

I want to try this out, the idea just popped into my head.

I thought about this too but the only thing that scares me is the PCM jumps back and forth with fuel.. constantly crossing the 14.7AFR border so it could lean spike a few times in the process and you'd have to have it floored a while for the PCM/Datamaster file to fill up with enough useful data (lterm fuel trims take a while to shift).

I think it's worth a try.. I just dont want to be the one to try it :D

I have a nifty device too, hooks up to your AC line, and Wideband, so when i log with Datamaster I can see the AirFuel ratio as well under the AC pressure, so 147psi equals 14.7AFR, 120psi is 12.0 :) pretty nice as I can actually log, had a good friend build it.

Now lets not get carried away and all start comparing our nifty Devices LOL :)

I read you can do this by setting the "Custom Engine Data" info in Datamaster 3.5.1 in the following way and hooking up a wire from your WB output to the pressure plug without any additional hardware:
Byte #: 30
Information: Air / Fuel Ratio
Variable Name: Wideband 02
Units: AFR
Gain: .05896
Offset: 7.35
Data Type: INT
Display Format: 0.00

Once the above is entered, all you have to do to see it is open the "Custom Engine Data" window and scroll through your log as usual. I think you can view logs created with 3.4.1 with 3.5.1 with no problems as well.. same data shows up. As far as I can tell 3.4.1 doesnt have the "Custom Engine Data" Window.

I set it up just never ran the wire from my wideband so I cant confirm it's accuracy, if it's not accurate then adjust the Gain and Offset.

Ah ok, I thought you were actually adding fuel via PE still

Thats super cool I never tried that portion

Can someone hook me up with the $EE definition file that has the BARO RESET MAX RPM constant setting but does not have the table headings renumbered? jhuegen AT gmail.com

Thanks in advance!

I got my 2 bar map from GM parts direct today, and my pigtail will not plug into it. What did you guys have to do to get this to work?

GM #12569241

Grind or cut at the connector until it fits. There's an extra slot in the housing around one of the pins on the connector.. you can see it by looking in the new sensor.

Grind or cut at the connector until it fits. There's an extra slot in the housing around one of the pins on the connector.. you can see it by looking in the new sensor.

Empty your PM box:)

Can someone hook me up with the $EE definition file that has the BARO RESET MAX RPM constant setting but does not have the table headings renumbered? jhuegen@gmail.com

Thanks in advance!

Anyone? I have the latest $EE from TC (dated 2008/02/21) and it doesn't exist in there.

Anybody have some data to post?

I've been hitting this tune pretty hard... meaning random mph vs rpm vs gear while dropping 100%TPS at random... new Z06 pulls up about 80mph... suddenly the TA drops into 3rd gear...then 100%TPS thru 140mph.. Z06 owner all pissed off im sure...

PCM's responding with 0 problems... no knock.. still repeatable WOT AFR's. Before the baro reset mod fueling was a mess in this situation.

Empty your PM box:)

exactly why I dont empty the box.. I hate "READING" what people send to PM boxes.

Forums are here for people to refer too. Any idea how long it takes to resolve a problem when you finally find something your talking about only to find out it ends in.. PM SENT??

AKA - MY PM IS FULL ON PURPOSE.

Post if you dare. Thank you.

exactly why I dont empty the box.. I hate "READING" what people send to PM boxes.

Forums are here for people to refer too. Any idea how long it takes to resolve a problem when you finally find something your talking about only to find out it ends in.. PM SENT??

AKA - MY PM IS FULL ON PURPOSE.

Post if you dare. Thank you.

you responded to my email so :p

Thanks again!!!!

Anyone? I have the latest $EE from TC (dated 2008/02/21) and it doesn't exist in there.

My file from TC was received 3-10-08, file is dated 3-10-08. Send TC some money and you'll get the updated file Im pretty sure.

This is simply the single most important update for 2bar MAP users to date and TC should get all credit for it. LT1_Edit can do it however they dont update software very often or make it easy.

I'm OBDII and TC sent me an updated vdf_08 version X and it Includes the Baro Update RPM Threshold.

\Send TC some money and you'll get the updated file Im pretty sure.

I figured since it was something only a few people had and since it wasn't included in the standard $EE file, you guys had something custom.

My $EE is paid for. All you had to say was email TC for it...

Is there any chance that JET will update there stuff with this new Baro update???????? Or could I get someones tune for OBD2 that has this set so I have a place to start?
Any help would be appreciated.
Thanks

I recently tried this tune in my 396 LT1 w/ 42# injectors. I changed the constant for my 42# to 22#'s. Am I correct in doing this? I also changed the cylinder volume size for my application. After doing this, I installed the 2 bar map sensor, unplugged my maf, and installed the 2 bar tune (although w/o the new defintion file. Just received it today via email) my car will start but immediately die. Wont stay started. This is the 2 bar tune, engineermike sent me. Dont know if or what Im doing wrong. Im confused. :( Can anyone help a brother out... Dookie, Mike, bueller........ :)

Thanks,

Eric

Could be any number of things. Try giving it some gas to see if you can keep it running and get a sense of whether it's rich or lean. It may be that the injector constant isn't low enough. Mine is 30 for 84's. Also, the minimum pulsewidth may be messing it up. I think that would make yours way too lean at idle.

Cool, thanks. I did give it some gas, but it persisted to die. I didnt wanna try and mess with it anymore, so I disconnected everything and put everything back to the the way I had it for now.

Yeah, I dont have as big an injector. I plan on getting either Mototron 60#'s or the Racetronix 79#'s.

Do you think I should hold off on this tune, until I get me a little larger injector. Or, maybe change my minimum pulsewidth to what I had in my orginal tune and going from there? Im really, really "green" at all this stuff. Im sorry.......

How do you figure what value to use for your minimum pulsewidth? Is there a certain formula I could use?

Man, this is some scary sh#t! :)

Eric

I recently tried this tune in my 396 LT1 w/ 42# injectors. I changed the constant for my 42# to 22#'s. Am I correct in doing this? I also changed the cylinder volume size for my application. After doing this, I installed the 2 bar map sensor, unplugged my maf, and installed the 2 bar tune (although w/o the new defintion file. Just received it today via email) my car will start but immediately die. Wont stay started. This is the 2 bar tune, engineermike sent me. Dont know if or what Im doing wrong. Im confused. :( Can anyone help a brother out... Dookie, Mike, bueller........ :)

Thanks,

Eric

I had the same problem. My car ended up being to lean to run. My injector constant is at 15 and I have 60 lb injectors.

I wonder if there is a point to where you can set the constant to low?

...Do you think I should hold off on this tune, until I get me a little larger injector. Or, maybe change my minimum pulsewidth to what I had in my orginal tune and going from there? Im really, really "green" at all this stuff. Im sorry.......

How do you figure what value to use for your minimum pulsewidth? Is there a certain formula I could use?...

The problem is this. . .

When I sent you the tune, it had a minimum PW of 1.4 ms. Mine ran rich from 25 kpa and down, so I kept lowering the VE and it stayed rich. Later, I lowered the minimum PW down to 1.0 ms and everything at low load went way lean. Before, the 1.4 ms PW was "propping up" the low load end of the VE table. When I got rid of the "prop", it went lean because my VE values had evolved into numbers way too low.

With your 42's, the minimum PW of 1.4 is probably fine. So, the low end of your table is probably very lean. As a test, you can raise the minimum PW to 2.8 and it runs ok, then that's the problem. Put it back to 1.4 then start richening up the low load VE.

Mike

I recently tried this tune in my 396 LT1 w/ 42# injectors. I changed the constant for my 42# to 22#'s.
Eric

I agree with what the Engineer has to say,

Im also thinking you might not want to bother with this tune until you get larger injectors only because the amount of work involved getting your base tune right then one day probably soon you will change injectors and it will be all messed up again.

I think I was maxing my 42lb's with 6-7psi if I remember correctly?

In the meantime you could lower your injector constant some more... maybe to 15-20? Sounds like it's lean since it fires right up then stalls, that's what mine did when lean. Usually too rich wont fire back up right away since it's basically flooded and you went too low.

If you look at your injector size vs entered number you'll see it's much more than 1/2 off, my 82lb = ~30, EngineerMike's 84's = 30, Jchevy's are 60's = 15, you might even need lower to less than 15 for 42's. Some of the "extra" taken off was to cure lean tip in, but you could try and see what happens. If you lower it too much and it only fires once then stalls and never re-lights, then it's flooded.

I would simpy lower the injector constant more and if that doesnt work perfect then wait for some larger injectors and save yourself some hassle unless you enjoy constantly programming your PCM... I think Im at ~220 loads or so? I started numbering around the 100th or so file, and started the sequence at 1, now I'm at about 131 or so... I might be done for awhile until I hook up my widewand simulated 02's...

Man, you guys are great! Thanks for all the help and information. Im not really looking forward to keep loading tunes, so it'll stay 1 bar for a while longer. I think I will wait and order some larger injectors.

Im leaning towards the racetronix 79#'s.

Once again, thank you all for your help. :)

Eric Bazan

I also changed the cylinder volume size for my application. Eric

Did you by chance half the cylinder volume?

Did you by chance half the cylinder volume?

No, am I supposed to half my cylinder volume, also? :eek:

Eric

No, am I supposed to half my cylinder volume, also? :eek:

Eric

Dont halve the cylinder volume!! DO NOT!

I think by doing that your cancelling out the injector size halving? or something like that.

I basically just downloaded the tune that engineer had into my computer, but changed what pertained to my vehicle. I dont remember if engineer's car is an A4 or an M6, but my car is an M6. Would this cause the issues Im having? Also, I didnt change the VIN. Another, possible reason? Like I said, Im really "green" at this tuning stuff so I hope Im not coming off as an idiot. Maybe should start another thread, that way Im not putting information that is not pertinent (SP?) to this thread. If so, lemme know.

Thanks

Eric

I basically just downloaded the tune that engineer had into my computer, but changed what pertained to my vehicle. I dont remember if engineer's car is an A4 or an M6, but my car is an M6. Would this cause the issues Im having? Also, I didnt change the VIN. Another, possible reason? Like I said, Im really "green" at this tuning stuff so I hope Im not coming off as an idiot. Maybe should start another thread, that way Im not putting information that is not pertinent (SP?) to this thread. If so, lemme know.

Thanks

Eric


Mine is a M6

When dealing with 1/2 resolutions things have to be closer, and your the first to use this tune with such small injectors.

If you can tell if it's rich or lean (sounds to me reading words is lean) then you need to richen it up.

It took a lot of modifications to engineer mikes tune to get mine to even idle. With the lean spot(27kpa), it would show it was lean on my wideband just after startup so I would add fuel. Then it wouldn't run because it was rich. I also had to change my startup VE to get it to start smoothly.

engineermike or 1982z28with18s, did you guys ever figure out your lean spot at 27 kpa?

Thanks,

Eric

engineermike or 1982z28with18s, did you guys ever figure out your lean spot at 27 kpa?

Yep, it was the minimum PW. I changed that to 1.0 and everything below 30 kpa went really lean. I had been reducing the VE in the <25 range trying to get it to stoichiometric, not realizing the injectors weren't allowed below 1.4 ms PW. Once I changed it to 1.0 and started adding VE down there, the problem went away. Apparently, I've been rich at low load ever since I put in the 83# injectors.

Mike

Changing the minimum PW helped mine a lot, I just spent one night on driveability and it drove great after that. It would still hit that lean spot though, but wouldn't lean out as bad(15.7-15.8) so I wouldn't even notice it when driving really.

Just giving an update... I've been running Closed loop forever with a somewhat larger cam and finally decided to turn off the 02's and realized 75% of the cam surge was due to the 02's. Now, I think one reason why it always seemed to run very good was I was loading new files almost every time I drove it (sometime every day) and the 02' s didnt have time to mess the Lterms up but just the other day I loaded a new file and I noticed the difference immediately.

After turning them off I was suprised how well it actually ran with no other modification... it actually ran rich (~12.0-14.0) according to the WB02 (anything above 900mv on the NB02 = lower than 14.0AFR) the thing is I am now able to cruise at 10mph in first gear without clutching it (Alum Flywheel, Mcleod twin - no springs). Impressive to say the least.

Back to the 2 Bar Tune... the reduced resolution is again not causing any problem for me even with the 02's not feeding input.. I made only a couple changes to some light load cruise AFR and idle AFR.. both changes (+ or -1 to each value in the SD tables gave me ~0.25-0.5 AFR).

I do notice a wall - Major increase in AFR at anythign less than 0.99 Msec for the injector pulsewidth (think the unit is Msec anyway) but that's because of the 83lb injectors and that low flow rate is only used when I'm actually decelling from 2000rpm and the "decel fuel cutoff" hasnt kicked in (Datamaster cells turn Yellow or Red I dont remember) and I think that's the PCM limit.. not 1 or 2 bar limit.

The weather was cool here this afternoon and I did a lot of tunning for my 2 bar map. Ive got drivability pretty good. Still a lean and rich spot here and there but for the most part I could drive the car everyday and not worry about it. Its a SD, open loop tune.

I guess you can add me to the list of people running a 2 bar map tune with a stock pcm! Couldnt have done it without this thread!!!

That's sweet Jchevy... this site really does RULE!! All the progress on this tune in such short time pretty amazing. The tune really runs good for me.. I can jam the throttle at any RPM or LOAD and it's smooth and ready to go.. after playing around in open loop Im an idiot for trying to make closed loop work and think I could change anything since it all reverts back to the same readings anyway... Open loop is far easier to change than I ever imagined... only 2 or 3 changes and Im good... I made probably 20 changes in closed loop only to find the flat spots keep coming back... annoying!


Hey Engineer, I tried to PM you but your full like I was.,, the 2bar setup still working good for you? What max boost are you running and how's it handling it? Im still at 7psi.

I just went Open Loop and it's better than Closed loop with my cam, everything else is perfect.

Im thinking it runs smoother in the cam surge area if AFR's are closer to 13.5 - 14.0 rather than 14.5... thinking this could be because the WB02 is reading incorrectly?

Wondering what will happen with weather changes or winter time, do you know if that throws off the AFR?

Next time you see a Prius pass them with tires smoking.. they apprieciate it.

Are you guys using TunerCat? In mine, you can select a number lower than 1.0ms for the min. PW. It looks like the scroll bar stops at the left at 1.0ms, but if you use the up/down arrows or manually enter a lower number, you can get it lower than 1.0ms. Maybe that will help you guys?

This is definitely a great option for people running big boost on LT1s!

I do notice a wall - Major increase in AFR at anythign less than 0.99 Msec for the injector pulsewidth

What's your minimum pw set at?

.. after playing around in open loop Im an idiot for trying to make closed loop work

I've never even attempted to tune it in closed loop. I've been open loop the whole time. The computer correction either masks or creates problems. In open loop, you get what you get, if that makes any sense.

Hey Engineer, I tried to PM you but your full like I was.,, the 2bar setup still working good for you? What max boost are you running and how's it handling it? Im still at 7psi.

Mine is working great. I do have a strange re-start problem I have to work out, though. It starts fine the first time, but if you kill it soon after it doesn't want to start. Also, if it doesn't start immediately when you hit the key it will be stubborn after that.

I'm running 17 psi boost with it right now. However, I do have Meth injection taking care of some of the high boost enrichment. I love this setup because the A/F ratio is 14-15 at cruise and, as you put your foot down, it richens up to 11-12 instantly. With the old MAF and closed loop tune, it had a lean tip-in pop, then pig rich, then it would lean out to around 11/1.

Wondering what will happen with weather changes or winter time, do you know if that throws off the AFR?

The Speed Density calculations take into account the IAT reading when calculating the fuel. It should work fine.

I became much more comfortable with tuning a car this way when I started checking out my jet ski's ECU. It's supercharged (converted to a turbo now) from the factory and runs 2.5 bar speed density with no MAF and no O2 sensors at all. Those things run great. I'm making ~280 hp from a 1.5 liter engine at 14 psi boost and all is well.

Mike

Its really exciting seeing you guys get this far with this.

I had a issue in my 93 LT1 calibrations with the airflow modes not matching at all with the o2 threasholds. The result was the car was constantly trying to trim itself way to lean. I eventually plotted O2 sensor voltage with WBAFR and manipulated the threashold tables to tune for the desired closed loop AFR>

I do have a strange re-start problem I have to work out, though. It starts fine the first time, but if you kill it soon after it doesn't want to start. Also, if it doesn't start immediately when you hit the key it will be stubborn after that.
Mike


If your using some or part of my original file I wonder If I may be partially responsible for the re-start problem since Im having the same symptoms and I do remember messing with some of those settings... there's a bunch of settings for this in Tunercat which I messed with in the beginning.
If your not using it then these settings need to be adjusted, either way Tunercat has settings for these.

If you'll notice when you shut the car off then soon try to re-start sometimes it tends to fire just a bit, usually at this point I let the key go then it stumbles then stalls then I have to hold the key for 3-4 seconds and it will start fine. During the 3-4 seconds of crank if I tap the gas it will fire right up and run fine with no recovery... if it were flooded or cranking too rich then there would be some rough running for a few seconds to clean out the extra fuel, in my case once it's running it's good which makes me think it's leaning out upon re-start.

Now, in tunercat there are settings which I think hold the key to fixing this problem (comparing hot coolant temps to colder ones which seem to startup fine)
1) Crank AFR vs DIst Reference... (jumps from 9AFR to 12AFR from 68 to 80c...)
2) Extended Crank AFR vs DRP... (jumps from 6.3AFR to 12AFR from 32 to 40c)
3) Prime Pulse Width vs Coolant Temp... I think this is what gives you the very first blast of fuel... or the very first fire up.. I notice the actual initlal fire force uppn startup is weaker in warm temp than cold.. cold temps are actually pretty fierce on the initial crank fire up... somethign like when cold (below 70F) the first 1/2 second of cranking it revs to 1200-1300 instantly like it skipped all the lower RPMs :) sounds cool like it really wants to start then RPM's come down instantly to whatever else controls it.. maybe Initial Startup AFR Enrichment vs Coolant temp? (#5 below)
4) Added Prime Pulse Width Enable vs coolant - I thin this is "Extra" and not used unless engine does not start in allowed time according to #5 (liike a person deciding to start pumping the gas faster or getting out and closing the choke on a carburated car)
5) Added Prime Pulse Enable - I think this enables the above calculation (#4)
6) Initial Startup AFR Enrichment vs Coolant....

I think since the intial fire actually happens under all temps then 1-3 are ok, but #4 and 5 might need some adjustment? Seems like the settings for cold (0F-~150F) are ok or good enough since it seems to start fine unless coolant temp is still up near normal operating temp. I think #4 has something to do with this since if you keep cranking I can see a steady increase in it's ability to start on it's own like it's slowy increasing fuel until it starts.

And I am also suprised how easy full SD mode is to tune once you use VEMASTER to at least get them close to where you need them - I cant imagine initially manually writing (guessing) at all those cells.. wow

Good to hear about the high psi.. all i need is a pulley and fuel pressure.. and a little more tuning :)

Its really exciting seeing you guys get this far with this.

I had a issue in my 93 LT1 calibrations with the airflow modes not matching at all with the o2 threasholds. The result was the car was constantly trying to trim itself way to lean. I eventually plotted O2 sensor voltage with WBAFR and manipulated the threashold tables to tune for the desired closed loop AFR>

This is also what I concluded from my setup running closed loop.. the 02's are making the engine run lean, not rich but likely only during low idle/low load situations. Because of this I think manipulating the tables using a WB might make all other off idle/med+ load conditions overly rich? Just one more reason I feel like gutting my 02 harness.. but the 02's really did help during the initial setup of my tune so I have to say they are useful for something.

Could someone check over my first crack at a 2 bar tune. It was done using dans tune as a base. And i would like someone to check it over before i change to a 2 bar map/tune etc...

stock lt1

5-9 psi of boost

meth

want to hold 14 degrees of timing in boost (used cant get wot timing below 26 deg for help)

added alot of extra fuel at 55 kpa and above to hopefully keep it safe the first time i hit boost, will lean out as necessary.

60# mototrons, injector constant set to 15 #

baro reset = 0 rpm

open loop

I have 1 o2 sensor in the downpipe right now wired to both banks of the pcm. Running on a 1 bar tune, two different o2 sensors keep reading lean for me. Tried running ve master on the 1 bar tune since i just recently switched to sd and the car starts reaking of fuel and drives worse then before. And the o2 still reads lean. I cannot detect any exhaust leaks. I would like to be able to use ve master to bring the drivability into check but i have been unsuccesful with the 1 bar tune so far. Any suggestions or should i just do this all open loop with a wideband and datamaster?

I can email to anyone who is willing to check it over for me. Thanks alot guys.

stock lt1 <--- Does that mean stock cam too? Then you should 1/2 the stock file's MAP values and paste them in there or did you allready do that?5-9 psi of boost
meth
want to hold 14 degrees of timing in boost (used cant get wot timing below 26 deg for help) <---- WHAT DOES THAT MEAN?

added alot of extra fuel at 55 kpa and above to hopefully keep it safe the first time i hit boost, will lean out as necessary. I just creep up on it slowly.. I also added alot only to take it right back out..

60# mototrons, injector constant set to 15 # <---- If it starts then your good. If it doesnt start keep playing with this setting until it starts but make sure your not flooded cause then it will mask your good settings (might want to hold to floor once in awhile to see if it is flooded)
baro reset = 0 rpm

open loop

I have 1 o2 sensor in the downpipe right now wired to both banks of the pcm (yea I tried this with the WB02 in the left side header and the one bank that was under control made the other bank that was not in control go crazy.. well not really crazy but I did notice the BLMS were decreasing? to the point the SES light came on since the right side thought it was rich and kept pulling fuel.... people told me it wouldnt work for exactly this reason but I tried it anyway ;) Now moving it to after the Y may work I dont know :D... . Running on a 1 bar tune, two different o2 sensors keep reading lean for me. Tried running ve master on the 1 bar tune since i just recently switched to sd and the car starts reaking of fuel and drives worse then before. <---- This may actually be because you only have one 02 in there and the PCM is adding fuel? In my setup it was pulling fuel so I dont know... And the o2 still reads lean. I cannot detect any exhaust leaks. I would like to be able to use ve master to bring the drivability into check but i have been unsuccesful with the 1 bar tune so far. Any suggestions or should i just do this all open loop with a wideband and datamaster? <--- YOu cant use VE Master unless you have two 02's hooked up for the reasons I posted earlier becuase the side with the 02 missing (or not in the correct side will be receiving false feedback) I have a whole post somewhere about the one 02.. pretty much I look like an idoit for trying it.. haha :) One day I'll post results with one 02 after the Y... who knows...I can email to anyone who is willing to check it over for me. Thanks alot guys. If you want to send to codytherott at hotmail dot you know what then feel free but I cant promise anything

Thanks for the reply dookie. Im gonna play with it some more this weekend.

Im trying to adapt the stock timing and ve tables over to a 2 bar tune and I just want to make sure I got things straightened out here. Im having some trouble setting up the 20-50kpa tables.
My car normally pulls about 36 kpa at idle. Is it safe to say that I can use the 30 or 35kpa column from the one bar tune as my 20 kpa column in the 2 bar tune?

Values in the 20kpa column “2 bar tune”= (Values in the 30-35 kpa column “1 bar tune”)/2
then
Values in the 25kpa column “2 bar tune”= (Values in the 50 kpa column “1 bar tune”)/2
Values in the 30kpa column “2 bar tune”= (Values in the 60 kpa column “1 bar tune”)/2
Etc etc etc
Am I correct?
Now if I understand this correctly you DO NOT divide by 2 when doing the timing? So it would be
Values in the 20kpa column “2 bar tune”= (Values in the 30-35 kpa column “1 bar tune”)
Then
Values in the 25kpa column “2 bar tune”= (Values in the 50 kpa column “1 bar tune”)
Values in the 30kpa column “2 bar tune”= (Values in the 60 kpa column “1 bar tune”)
Etc etc etc
Then the 55-100 kpa “2 bar tune” is all the tuning done in boost

Ok, Ive got my obd2 car running with the 2 bar map and only 5lbs boost and am already having some problems with the Baro reset issue. I'me tuning with Jet Dynamic Spectrum Tuner (only software I could find for my car at the time) and I have not found a way around this yet. Here are a couple questions.

1) Has anyone turned off the Baro Reset on an OBD2 program yet?
2) How can I get mine turned off when my software doesnt have the variable?
3) Could I send my tune to someone and have it turned off then I can just reload it in my software and tune this thing the rest of the way?

So far I really like the Way this 2 Bar setup is working but It's hard to nail this tune down when my datalog's will show the AFR at 12.9 on one pull with 53.86 Baro reading and then another pull with the exact same RPM and map and it will go 11.80 AFR with a 55.86 Baro......

Ok, Ive got my obd2 car running with the 2 bar map and only 5lbs boost and am already having some problems with the Baro reset issue. I'me tuning with Jet Dynamic Spectrum Tuner (only software I could find for my car at the time) and I have not found a way around this yet. Here are a couple questions.

1) Has anyone turned off the Baro Reset on an OBD2 program yet? Doubt it simply because this problem/feature was just discovered
2) How can I get mine turned off when my software doesnt have the variable? You cant unless you can talk one of the OBD2 companies/software into enableing the parameter in thier software and setting it for you then sending you the updated file.. Tunercat and LT1_Edit both offered up a modified file once I convinced them and they found and enabled the parameter.. I would think any tuning software company would appreciate this type of feedback and enable it for you at no cost
3) Could I send my tune to someone and have it turned off then I can just reload it in my software and tune this thing the rest of the way? Yes but you have to use that tune they sent back to you... because you cant see the parameter with your software just means it's there but it isnt looking at it, so if it's changed it will stay changed - this applies to Tunercat and LT1_Edit im not sure about other software

So far I really like the Way this 2 Bar setup is working but It's hard to nail this tune down when my datalog's will show the AFR at 12.9 on one pull with 53.86 Baro reading and then another pull with the exact same RPM and map and it will go 11.80 AFR with a 55.86 Baro...... This is what was driving me nuts for along time... so happy when the software was changed and the BARO stopped changing.. huge step forward

[QUOTE=cause4panic;5469734]Im trying to adapt the stock timing and ve tables over to a 2 bar tune and I just want to make sure I got things straightened out here. Im having some trouble setting up the 20-50kpa tables.
My car normally pulls about 36 kpa at idle. Is it safe to say that I can use the 30 or 35kpa column from the one bar tune as my 20 kpa column in the 2 bar tune? This should get you close but best thing to do is see where it idles on the 2 bar tune, compare that to the 1 bar tune, then use approximately 50-55kpa on the two bar tune compared to 100kpa on the 1 bar tune and make your divisions.. it'll be more accurate that way... simply halving them might get it close enough to start then you can use closed loop and VE master to get the rest.. just make sure you copy the 50+KPA from the non-vemaster file to the new 2bar file since VEMaster assumes/makes up numbers for increasing load even when it doesnt get values for them... if you dont copy the old 50+kpa values eventually it will be very rich under boost

Ok, Ive got my obd2 car running with the 2 bar map and only 5lbs boost and am already having some problems with the Baro reset issue. I'me tuning with Jet Dynamic Spectrum Tuner (only software I could find for my car at the time) and I have not found a way around this yet. Here are a couple questions.

1) Has anyone turned off the Baro Reset on an OBD2 program yet?
2) How can I get mine turned off when my software doesnt have the variable?
3) Could I send my tune to someone and have it turned off then I can just reload it in my software and tune this thing the rest of the way?

So far I really like the Way this 2 Bar setup is working but It's hard to nail this tune down when my datalog's will show the AFR at 12.9 on one pull with 53.86 Baro reading and then another pull with the exact same RPM and map and it will go 11.80 AFR with a 55.86 Baro......

I have Tunercat for OBD2. Bought it before TC sold it to Jet. Tunercat sent me the update for baro reset about 3 months ago. I changed the baro reset to 500 rpm and it works like a charm on my MAF tune.

I don't think TC supports the Jet OBD2 software anymore though.

I have Tunercat for OBD2. Bought it before TC sold it to Jet. Tunercat sent me the update for baro reset about 3 months ago. I changed the baro reset to 500 rpm and it works like a charm on my MAF tune.

I don't think TC supports the Jet OBD2 software anymore though.

yea.. can you tell I didnt know TC makes OBDII stuff? haha.

I have Tunercat for OBD2. Bought it before TC sold it to Jet. Tunercat sent me the update for baro reset about 3 months ago. I changed the baro reset to 500 rpm and it works like a charm on my MAF tune.

I don't think TC supports the Jet OBD2 software anymore though.

I just downloaded the new verson of DST (1.48) and it has the Baro reset in the Fuel Paramaters constant which I reset to 500 rpm. I'll test it later this weekend and see if it works!

yea.. can you tell I didnt know TC makes OBDII stuff? haha.

I changed the min pulse width to 1.0 in my tune and it helped my car to obtain stoich on decel and light throttle. Thanks Dookie!!!:)

I just downloaded the new verson of DST (1.48) and it has the Baro reset in the Fuel Paramaters constant which I reset to 500 rpm. I'll test it later this weekend and see if it works!

Hey Guitarman what is DST? I've never heard of it. (I havent heard of much). If it says "BARO RESET" that is definetly it, you can double check but the stock setting should be 3600rpm, if it's not around 3600rpm it's probably allready been modified.

I changed the min pulse width to 1.0 in my tune and it helped my car to obtain stoich on decel and light throttle. Thanks Dookie!!!:)

Cool!! I've been noticing if I change that value to anything below 1.0 I hit what seems like a wall with my 83lb'ers... pretty much on decel once the pcm starts calcuating pulswidth below 1.0ms it seems like it just shuts the injectors off completely since AFR's start increasing beyond 40-50+, must be the PCM minimum limiit huh?

I read somewhere (I think the megasquirt website) that it takes injectors 1 ms to open. So, with a commanded PW of <1 ms, they are getting the signal to close before they even reach full open. I'm not sure what the result would be, but it could explain that.

Mike

Hey Guitarman what is DST? I've never heard of it. (I havent heard of much). If it says "BARO RESET" that is definetly it, you can double check but the stock setting should be 3600rpm, if it's not around 3600rpm it's probably allready been modified.

DST is Jet's version of Tuner Cats called Dynamic Spectrum Tuner. Yup it was set at 3600 and dropping it to 500 rpm fixed my problem. I worked a bit more on it yesterday and it seems to be working perfectly. I'm working with E85 in Open Loop and 5lbs of boost so far and while the tune is still not great (lack of time to actually work on it) it's pretty darn good and seems to be pretty responsive to my changes. Only problem I'm having is with my data logger which is called MXScan and it really sucks because it doesnt have a graph function so I have to put my .csv files in Excel and try to graph that way....it's ugly. Oh well, still works and I will get this thing dialed in soon so I can up the boost.

I read somewhere (I think the megasquirt website) that it takes injectors 1 ms to open. So, with a commanded PW of <1 ms, they are getting the signal to close before they even reach full open. I'm not sure what the result would be, but it could explain that.

Mike

Mike - makes sense since I guess at some point this would have to happen. So is it safe to say basically any ECU or programming that goes below 1.0ms using this size injector may have the same result? I just keep it at 1.0ms and everythings fine I wonder if that's what everybody does.

Got it running/driving on the two bar last night. Car idles at 22-23 kpa.

Took the values from where the car previously idled (35 kpa), stuck them in the 25 kpa cells. Then took all the other values and divided by/2 (70kpa into the 35 kpa cells etc etc).

Car started up smoothly on the first try. Little rich at idle but after a few minor tweeks it was completly driveable and smoother then my 1 bar tune.

Im gonna run my ve's and timing tables through an excel sheet to smooth out the transitions and start logging my wideband. After that!!!! BOOOST!!!!

You guys rock!!!! Thank you for all the help until now.

What tunercat heading is this under? I'm looking at the available "Tables" and I don't see a heading of "Min Injector Pulsewidth". Is it a sub table under another heading?
THanks!

My setup:

Like said, make sure you lower your MIN injector PW to around .5 or so which is what I did, you'll also notice that if you ever hit lower than 1.4ms which is stock MIN, your BLM will flatten at 128blm, when I first noticed it thats when I changed the MIN PW to .9 than to .5.

Im having a slight issue with surge while in park. What should i be looking at to resolve this?


dave, min injector pw is under ecm constants.

What tunercat heading is this under? I'm looking at the available "Tables" and I don't see a heading of "Min Injector Pulsewidth". Is it a sub table under another heading?
THanks!

What tunercat heading is this under? I'm looking at the available "Tables" and I don't see a heading of "Min Injector Pulsewidth". Is it a sub table under another heading?
THanks!

Constants>Fuel Parameters... If you have the latest version which is X for Tunercat for OBD2

When I was running H/C I found setting the idle spark advance to 30 degrees seemed to fix that surging.

Im having a slight issue with surge while in park. What should i be looking at to resolve this?


dave, min injector pw is under ecm constants.

Im having a slight issue with surge while in park. What should i be looking at to resolve this?

.

I had the surging problem when I lowered below 1.0 or 0.9ms... I think what was happening was the fuel injectors were totally shutting down with any Pulsewidth below about 1.0ms, so it would basically die out any time the PCM calculated less than 1.0ms... I raised it slightly to 1.0 and the problem is totally gone.
EngineerMike explained the injectors may not be able to open or squirt fuel with less than 1.0ms.. makes sense to me since any time I see pusle width's under 1.0 the box turns yellow and the AFR goes WAY up (20-30:1 AFR), the 1.0 setting keeps the injectors firing at 1.0 even if the PCM says 0.8.

I just cant seem to get this thing to idle correctly in park. When in drive it tries to achieve 600 rpm idle. But when i put the car in park it does not try to achieve the 700 rpm that is commanded. But i should be able to get this thing to idle at 600 rpm. I DONT GET IT!!!!

You can drive around all day with no issues, timing seems good, wb02 readings seem on the money. Place it in park and it WILL idle for maybe 15 seconds without issue. Then you start noticing the surge, it keeps getting worse until the car finally stalls out.

min pw is set to 1.1
closed tps advance 28 deg

Could someone look at my file? Just let me know which emails to include.

Thanks guys.

P.S. havent hit boost yet but after tuning the around town stuff by hand i can say that it shouldnt be a problem.

I had the idle surging problem after I changed a few things.... those things were:

1) Messed around with the MAF tables.. I returned to stock and it went away, now I run SD mode
2) Messed with the min pulse width and set too low
3) Your Idle AFR may be off causing strange problems

At what point did the thing start to have this problem? Whatever you changed is probably what needs to be adjusted.

When I originally loaded the 2 bar file it was doing it. What should my idle afr be? Right now it hovers right around 14.7

Could someone please PM me the latest 2-bar file? Im working on this and would like something to compare to.
Gary

Anybody? hope this thread wasnt given up on. Im having a few problems with my VE table, someone post a file?

ill send you a few I had played with when I get home from work

Let me see if I can find it.
Found it..
http://www.taekwondoplus.org/z28/Turbo/Dan_141_OpenLoopSD.lt1

Thanks, ill try that out tomorrow
Gary

Let me see if I can find it.
Found it..
http://www.taekwondoplus.org/z28/Turbo/Dan_141_OpenLoopSD.lt1

Are you running a 2 bar SD tune now? I thought you had a BH mail order tune? The last time I talked to BH he was still doing MAF tunes up to about 600 RWHP.

I am still (Happily) running BH Maf tune. I was investigating running the SD tune because my NB O2 sensors are not happy in their current configurations. The passenger side is fine but because of design restrictions, the drivers side is in the downpipe and as such is essentially measuring not only the drivers side but the passenger side again. As a result, my wide band was all over the place at cruise. With the NB O2 sensors disengaged, it's much smoother now. Essentially, it's an Open Loop all the time MAF tune now. The plugs reading is a bit puzzling now though. All four drivers side plugs look perfect while all four of the passenger side plugs look a little cruddy. The engine isn't smoking, nor losing coolant and runs great.

My car is running pretty good. Just got it back up and runninmg with the new motor so Im still tweaking.

Ive also adapted this to E85!


On the lean side here though, i was pretty low on gas, I think it might have been sloshing around a bit.
http://home.comcast.net/~jared111481/boost1.jpg

My car is running pretty good. Just got it back up and runninmg with the new motor so Im still tweaking

Ive also adapted this to E85!
.

What a cool pod setup! <jealous>
I like that boost controller in the 3rd pod(or is that considered the 1st pod?)
Very cool picture.

What a cool pod setup! <jealous>
I like that boost controller in the 3rd pod(or is that considered the 1st pod?)
Very cool picture.

Thanks... Im anxious and nervous to give it another 5 PSI. I still have some more tunnign to do where its at.

BTW You gave me Brett Baurers contact info a while ago...I got a hold of him and he did a cam for me:)

Sweet :)
I'm real happy with my setup. The best of both worlds. The civility of a stocker and the lethal bite of a Rottweiler Lol...
Keep us posted on your findings as you bump up the boost! I'm heading home to Upstate New York for a month, then I'll be back to Houston to start bumping mine up as well.


Thanks... Im anxious and nervous to give it another 5 PSI. I still have some more tunnign to do where its at.

BTW You gave me Brett Baurers contact info a while ago...I got a hold of him and he did a cam for me:)

so i got this going last night with your VE map, and it was pretty accurate. I have my injector constant at 18.5lb/hr, and i think i need to go to an even 18. im still around 135blm at the moment. pretty impressed as the cruise and tip in is alot smoother as i expected. I think with this huge blower im still getting some pressure pulses over the MAF and it was washing it out some.
Gary

Im trying to mess around with warm startup settings now, seems like they got a little messed up after all the injector scaling.. best I can describe it is when the motor is near normal operating temp when I go to start it (minutes after shutting off) I have to crank longer than normal.. if I tap the gas it fires right up and everything is normal after that. There are settings in Tunercat just have to figure out what ones to adjust.

When motor is anywher near cool I crank it and it starts up very very strong and fast (1/10th of a second), once warm most of the time it takes 3-5seconds of continuous cranking to start.. even then it starts weakly then is normal. If I tap the gas while cranking it starts right up.. I think it's lean becuase there is no initial fire up like there should be if it's too rich.

Anybody have any ideas as to what setting this is? Theres things like Crank AFR, Inital Crank Pulse, etc.. if anybody adjusted anything and saw an improvement let me know!

Is everyone doing these on OBD I computers? My builder/tuner is saying that he is having a hard time getting everything completely finalized with the tune on my OBD II cars ans is saying I'll need to go the OBD I route. That's not something I really want to do. My car is bad enough as it is in relation to California law.

What is the Injector Min PW set to stock. I have LT1 edit and cant see it, but I have the lean spot right at 27 KPa. I am also rich when I am coasting in neutral.

My datalogs dont show my BPW mS any less than 2.0. Does this mean my problem is elsewhere?

Can I email a file to someone and have them change the min pulsewidth for me?

Is everyone doing these on OBD I computers? My builder/tuner is saying that he is having a hard time getting everything completely finalized with the tune on my OBD II cars ans is saying I'll need to go the OBD I route. That's not something I really want to do. My car is bad enough as it is in relation to California law.

I am on OBDI only because it was cheaper (I have 1996 car). Ask him what he's having problems with and be very specific.. I thought most of all of the tables are the same but the software is different... wondering if he has software that does not include the BARO Update settings then yes he will have problems for sure.

What is the Injector Min PW set to stock. I have LT1 edit and cant see it, but I have the lean spot right at 27 KPa. I am also rich when I am coasting in neutral.

My datalogs dont show my BPW mS any less than 2.0. Does this mean my problem is elsewhere?

Can I email a file to someone and have them change the min pulsewidth for me?

I think mine were ~1.4ms.. you have to use TUnercat to see the settings. If you have big injectors 1.4ms is way too high but dont set it lower than ~1.0 or they stay closed completely without showing it.

What is the Injector Min PW set to stock. I have LT1 edit and cant see it, but I have the lean spot right at 27 KPa. I am also rich when I am coasting in neutral.

My datalogs dont show my BPW mS any less than 2.0. Does this mean my problem is elsewhere?

Can I email a file to someone and have them change the min pulsewidth for me?

you can send to me if you still need help, dookie454 --> at --> gmail

so i got this going last night with your VE map, and it was pretty accurate. I have my injector constant at 18.5lb/hr, and i think i need to go to an even 18. im still around 135blm at the moment. pretty impressed as the cruise and tip in is alot smoother as i expected. I think with this huge blower im still getting some pressure pulses over the MAF and it was washing it out some.
Gary

Gary, just curious why you still use the MAF with the big blower since surely your maxing it out? Pure SD mode is working really good for allot of people.. well those of us that put tweak it enough that is :(

Pure SD here, open loop aswell. Lovin it :D Especially if you have a boost controller. I blew the charge pipe off one night now if i were running a maf it would have left me stranded on the highway.

Cheers to the op and everyone who is making this write up worth while.

I nominate this thread as a sticky

you can send to me if you still need help, dookie454 --> at --> gmail

If my datamaster logs are not showing the BPW mS to be less than 2.0 does this mean my min PW settings are ok though?

...
I nominate this thread as a sticky

I agree. This thread covers some of the most important issues with boosted LT1s. :thumb:

I'm going to talk with my builder more today to get some clarification as to what they are having a problem with regarding my tune.

If my datamaster logs are not showing the BPW mS to be less than 2.0 does this mean my min PW settings are ok though?

Yes you are right, if your BPW is not falling below 1.4ms then there's no reason to lower it (assuming 1.4ms is where the minimum is set).

Yes you are right, if your BPW is not falling below 1.4ms then there's no reason to lower it (assuming 1.4ms is where the minimum is set).

I sent you an email with a bin file since I dont have any way to check the BPW with my LT1 edit. If you have a second take a look at it.

I sent you an email with a bin file since I dont have any way to check the BPW with my LT1 edit. If you have a second take a look at it.

I think I just sent it back to you? pulsewidth was at 1.404 I changed it to 1.1 and the BARO RESET was allready at 500rpm.

I bought the car running MAF on OL with RPM enrichment. It didnt work for **** and i have it converted to 2-bar now. Ive ran all my vehicles SD as soon as i could afford it (02WS6, 04 GTO, 76mm LS2 etc.) Its just a bit harder to do this with the old software. HPTuners made the 2-bar setup so easy its sickening, its taking some time for me to learn all this tunercats stuff. Im not going to mess with it anymore this year but i do have it running pretty decent, cold starts and idle arent very good yet, and it surges while coasting in N. There is a dead spot when smacking the throttle sometimes too, but the driveability is so much better. Highway cruising is dramatically improved, and i picked up around 3mpg. Im going to have it fully tuned in the spring after some street tuning with a new wideband and some updates over the winter to get the boost up to about 18#, looking to make closer to 650whp.
Gary

cold starts and idle arent very good yet, and it surges while coasting in N. There is a dead spot when smacking the throttle sometimes too, but the driveability is so much better.
Gary

;) sorry this made me smile.

Lower Injector constant some more to fix dead spot when you smack it to floor. I smack mine all the time just to feel the crispiness. :eek:

My warm starts are getting better but not as good as cold starts.. my cold starts are scary strong and fast.. probably lights up in 1/10th of a second cold (instant I hit the key). Im thinking cold cranking is richer than needs to be but it's not causing a problem at all.

and it surges while coasting in N.
Gary

So i finally got around to installing my converter/tranny. Now the car surges when deccel. And when sitting at a light sometimes.

Should i be looking at iat steps? or min pw?

Have you altered closed throttle spark advance or decel fuel tables?

So i finally got around to installing my converter/tranny. Now the car surges when deccel. And when sitting at a light sometimes.

Should i be looking at iat steps? or min pw?

Have you altered closed throttle spark advance or decel fuel tables?

No i have not. How should i change them?



Edit:
Are these the tables i should be adjusting?

closed tps spark advance vs rpm
ve vs rpm vs map
ve vs rpm vs map ext
dfco enable %tps vs rpm
dfco exist spark blending vs tps
throttle follower iac offset vs mph

No i have not. How should i change them?



Edit:
Are these the tables i should be adjusting?

closed tps spark advance vs rpm
ve vs rpm vs map
ve vs rpm vs map ext
dfco enable %tps vs rpm
dfco exist spark blending vs tps
throttle follower iac offset vs mph


Looks like them to me, however check a log and see if your injectors are turning off causing the surge... I had that problem and it was DFCO MAP settings, then I messed with the Min Pulswidth setting (put too low) and the problem returned. Now I have those two items just right (min pulswidth at 1.1) and no more problems.

Can i just disable DFCO? It will only affect my engine braking right?

Can i just disable DFCO? It will only affect my engine braking right?

That and you'll get 0.00001 mpg worse gas mileage.

That and you'll get 0.00001 mpg worse gas mileage.

that's funny... 0.00001 mpg, funny because it's true and it sounds stupid. Only thing that ever bothered me without DCFCU is I ended up using brakes ALOT more and that got annoying on the Highway or in trqffic when your coasting cause traffic is slowing down and your thinking man sweet I dont have to use my brakes cause my DCFCU is slowing me down.. sweet...

I put a little work into it and got it just right. I was having a somewhat strong re-light I think becuase with 83lb injectors the min puslwidth of 1.0ms was just a little too much fuel for a spikeless return to ignition but I cured that by pulling a huge amount of DCFCU blend timing.. or whatever that was called - it seemed to pull timing during re-light and made it just about unnoticable.

can one or both you guys, engineermike and/or dookie454 send me your latest file?

Now that I actually have a turbo that spools, I've noticed the 14.4:1 AFR to 10.8:1 AFR switch at partial throttle...it's like someone put a VTEC in my engine when I wasn't looking because of the instant pick up in power, but then I look in the mirror and I realize it's just a high revving deisel and I should have a stack going through the passenger t-top to direct the cloud of black smoke.

email mkent93@yahoo.com

Sure, there are LT1's making great power on stock ECM's, but it is not an optimal solution. <-- saw that in another post...

Switching from 14.5 to 10.8AFR isnt good by any means, so spending $20 to run full 2bar control sure seems optimal to me.

If you think about the LT1 PCM.. it's plently good using a $20 2bar sensor. If I were building a project from scratch I might buy an LSx PCM however if your car runs with the LTx pcm and your under 7000rpm and ~15psi your good to go.

I would think anything over ~15psi if the 2bar maxes you could add some PE Enrichment and be fine since it's such small amount to carry you safely to ~18psi.

<-- saw that in another post...

Switching from 14.5 to 10.8AFR isnt good by any means, so spending $20 to run full 2bar control sure seems optimal to me.

If you think about the LT1 PCM.. it's plently good using a $20 2bar sensor. If I were building a project from scratch I might buy an LSx PCM however if your car runs with the LTx pcm and your under 7000rpm and ~15psi your good to go.

I would think anything over ~15psi if the 2bar maxes you could add some PE Enrichment and be fine since it's such small amount to carry you safely to ~18psi.


I've just switched mine back to gasoline from E85 (would like to run gas until I go to the track anyways and now here in michigan were back to E70 for the winter). With this 2 Bar setup I just scaled my injector Flow Rate by 1.30 to remove 30% of the fuel I was using on E85 and took some timing out under boost. Car started Is running great and only needed one tweak of the VE tables to get the AFR back into shape. I'm still looking for issues and have not found any that cant be fixed....I'm still only running 9lbs of boost though because my clutch wont hold in 4th gear.

I am seriously impressed with this thread, a serious congratulations to the guys who hit the send button and began the journey!!!

I went with DFI 4 years ago on my turbo LTx project because I was scared to death of hurting my motor with the turbo from poor PE enrichment tuning.

I always wondered if the maps could be scaled. You guys are basically doing the same thing I do in DFI by rescaling the maps to suit? or when you rescale them do the axis value remain linearly interpolate from smallest to largest? meaning can you add resolution to one portion and take away from another for part throttle tuning.

so from my reading it basically takes having tunercats which i do and a $20 2 bar map sensor to get to 15psi and 7000RPM worth of tuning parameter.. simply great work guys!!!!!!


Chris

I am seriously impressed with this thread, a serious congratulations to the guys who hit the send button and began the journey!!! Thanks, it started really because Im a cheap a** and also did not want to run in PE mode... also didnt want to shell out any more money.. motor came in way over budget.
I went with DFI 4 years ago on my turbo LTx project because I was scared to death of hurting my motor with the turbo from poor PE enrichment tuning.

I always wondered if the maps could be scaled. You guys are basically doing the same thing I do in DFI by rescaling the maps to suit? or when you rescale them do the axis value remain linearly interpolate from smallest to largest? meaning can you add resolution to one portion and take away from another for part throttle tuning. No, axis cant be scaled.. at least not with the software we're using.. I dont understand how all this time passed and noone got ahold of the original GM tuning software... at this point with basically 1/2 the stock resolution I dont have a single problem.

so from my reading it basically takes having tunercats which i do and a $20 2 bar map sensor to get to 15psi and 7000RPM worth of tuning parameter.. simply great work guys!!!!!! Yup, that's really all it takes! That also means you dont need MEGA fuel system since you dont need a FMU

One thing I would love is to get the Knock Retard signal out to a light bulb on the dash.. big red light... just for fun.


Chris


Made blue comments above

the buick world has what is called scanmaster which is a little black box they put on there dash and it connects to the computer.. it reads O2 millivolts, knock retard degrees, iat's, and a sleuth of other good to have information at the push of a button in red led lettering.. it may be something to look into as I am sure a simple splice in to the correct wires in the harness is all it would require since knock sensors, IAT sensor tps voltage is all relatively still the same.. may be something to look into!

Chris

There is an LT1 version of the Scanmaster.

:)

Scanmaster is ok, either they they seem hard to find or they are too much $? Dont remember why I never got one. Seems like there'd be an easy way to output the same signal the Laptop is allready seeing.. forward it thru serial port to trigger a bright Light on the dash is all I'd like.

I have this tablet PC thing, small size of a bible... logs at 10pts/sec just wish I could get that outputting the Knock Retard signal to a light or something.

By the time you have something that will process the retard signal and control an external light you are 90% of the way to something like the Scanmaster...

sounds like its time to organize a group buy.... :)

Well we're into the warming stage of winter and Im getting many requests to get a copy of the file so Im posting a link to it here, I thought it was on here somewhere but I cant find it (thought it would be easy to find, sorry about that). I also attached the datamaster log of this LT1_Edit file. Keep in mind all my previous posts were at ~7psi @ 6200rpm and this is the first run since switching to a stock size crank pulley (from undersized) and I expect to have 10psi at 6200rpm, in the one WOT run where I actually had enough traction and held 100% TPS it shows 80kpa at 5200rpm, never made it to 6200rpm.

Anyway this is one of my latest and might be what I have installed, runs good, only been to around 7psi with my 82lb injectors, AFR was around 11.8 around 7psi @ WOT, I max around 6200 rpm.

Idles good, open loop no problems however Im trying to figure out where I picked up some injector shut off (Decel Fuel Cutoff) type symptoms if you are in neutral free-reving around 1600-1900rpm it tends to happen, dont feel it when driving so I havent needed to look into it, but I think the same thing happens at idle just slightly... you problably wont even notice it, it might be something to do with the min pulswidth being slightly too low since the AFR spikes UP when it happens.

Just have to say use at your own risk, take it easy, dont just assume it will work for you, some of my specs are as follows:
1) Siemens 83lb injectors
2) No MAF (SD), never been tested so I have no idea what would happen with one aside from maxing at 5000rpm (pointless)
3) GM 2 bar MAP from an old school 1990? Turbo Sunbird or similar! haha haha
4) decent sized cam (definatly not stock)
5) No 02's since my cam messes them up and leans out idle/low RPM cruise
6) Timing is good for me with 92 octane, 7psi cooler weather havent checked it on hot summer day since last year
7) 3.23 gears for speedo on a Stock 1998 T56 retrofitted to 1996 type bellhousing
8) No EGR, etc

LT1_Edit File:
http://www.mediafire.com/file/12j2qrmdtkz/Dan_148_OpenLoop.lt1 - This runs good but has warm start delay and "exploding to life cold start"
http://www.mediafire.com/file/zo3zwgnwzm2/Dan_156_OpenLoop.lt1 - This one has warm start delay fixed and "exploding to life start" reduced to normal (reducing fuel in Crank AFR vs.... and Prime Pulse tables)

Datamaster Log (I just changed to stock sized blower crank pulley (from undersized) and expecting ~10psi at 6200rpm, this combo is showing ~80kpa at 5200rpm that's all I tested so far: ALSO KEEP IN MIND SINCE THIS IS 2 BAR ON STOCK 100KPA TABLES, WHAT YOU SEE IN THE BARO KPa is ATMOSPHERE, so anything over that in MAP KPa is BOOST! (if BARO shows 53.9KPa that means atmosphere pressure on this new scale is 53.9, anything over 53.9 is BOOST, so 100KPA in the MAP would be approx 14psi-ish, same goes for the LT1_Edit VE tables.. same scale, same values = simple tuning).
http://www.mediafire.com/file/iiddtxd1mjd/Dan_148.uni
.

My 3 WOT runs start around REC# 12402, none are full RPM due to 40% wheelspin and 60% me keeping car safe on a 2 lane road waiting for tires to heat up, but what worries me is at REC# 12692 there is a jump in RPM but not a matching jump in MPH, then RPM comes down just a bit with MPH still climbing a bit, makes me hope it's just sensor error and not clutch slipping (McLeod street twin on an aluminum flywheel), I know RPM error varies quite a bit but also slipping clutches mimick this behavior, as they slip they heat up and grab, just like tires.
.
.

To resolve the warm start delay I asked Tunercats about the following tables since I feel the last item to iron out is weak initial "light" during crank when warm. Adjusting tables below (#1 or 2) to increase "initial fuel during first crank" should speed up warm start drastically. I actually think cold "initial light" is so fierce that I may actually lean cold initial fueling just a bit and richen it up in the warm coolant temp tables. Seriously, cold crank ignites on what appears to be under 1/2 second of cranking and it jumps to about 1300rpm then back to 1100rpm idle.. pretty strong ignite in my opinion.

Previously I only adjusted #2, which I think helps but still it has to actually crank before it adds fuel.. I think #1 is exactly what I need to adjust to speed up intial start.. I would assume this goes for all 1995 and newer PCM's including LS1's since they want to make sure the engine is cranking good before adding fuel.

Seems like as cars get newer the more actual cranking you hear before the engine starts.. it appears these settings are 100% responsible for the delay.


Hi Dan,

1. 1st Prime Pulse Width Vs. Coolant Temp. table controls the injector pulse width of the first prime fuel pulse during cranking as a function of engine coolant temperature. Similarly the 2nd Prime Pulse Width Vs. Coolant Temp. table controls the injector pulse width of the second prime fuel pulse during cranking as a function of engine coolant temperature. These tables were in the '96/97 LT1 calibrations. In the '94/95 LT1 calibrations these two tables are combined into a single table (Prime Pulse Width Vs. Coolant Temp.).

2. The 'Crank AFR Vs. Distrib. Refer. Pulse Vs. Cool. Temp.' table sets the target AFR during cranking as a function of coolant temperature and the number of distributor reference pulses.

3. If the engine is still cranking after the time specified by the 'Added Prime Pulse Enable Crank Time Vs. Cool. Temp.' table then another prime pulse is output and the pulse width of this added pulse is specified by the 'Added Prime Pulse Width Vs. Coolant Temp.' table.

4. As soon as the PCM declares that the engine is running the fuel is temporarily enriched as specified by the 'Initial Startup AFR Enrichment Vs. Coolant Temp.' table. This enrichment is then gradually removed.


Best regards,

TC

My warm start delay annoyance problem is all fixed!! Starts right up warm like it did when stock FINALLY!

To fix it I had to actually LEAN out WARM CRANK FUEL by doing this:
1) Prime Pulse Width Vs. Coolant Temp
2) Crank AFR Vs. Distrib. Refer. Pulse Vs. Cool. Temp

Initially I thought it was too lean so I was adding fuel and this only made warm start worse, so I went back to stock then removed about 1/2 the values from stock and sure enough when warm starts right up cleanly everytime! No more tapping the throttle to get it to start. Bout time :D

Cold start also seemed to "jump to life" fiercly so I leaned out a little fuel there too now cold start seems normal as well. Makes sense since I had to pull about 1/2 fuel out of all the other fuel tables at some point.

Now there's nothing left to improve I guess unless I decide to go with a smaller cam so I can turn on closed loop. NAH, it runs too good this way.

Maybe now it's time to move on and concentrate on upping boost?

ok guys i need a little help with the 2 bar setup. exactly what all tables do i scale in half for the initial base tune in tunercat?I understand about only using a few columns and scooting them under 50kpa but which ones? Do i need to do the same with the tranny tables?

ok guys i need a little help with the 2 bar setup. exactly what all tables do i scale in half for the initial base tune in tunercat?I understand about only using a few columns and scooting them under 50kpa but which ones? Do i need to do the same with the tranny tables?

I dont know about trans tables but I would think anything with MAP tables get cut in half just like the timing table.

There's too much for me to remember, easier if you download the File I posted and compare any MAP based tables you can find.

Every single MAP based table should need scaling in some way, usually by 1/2 to start.

I might update the file with my #156 since I fixed a delayed warm start problem I was having then you can compare easier.

ok is that a tunercat file or a edit file?

I tried to save the file but it said that it wasnt there anymore?!?

I tried to save the file but it said that it wasnt there anymore?!?

It's and LT1 file and if you cant download it then maybe your internet blocking programs are blocking it.

No offense, but if you cant tell if it's an LT1 or Tunercat file then you should not be using it.

jeez man gimme lil bit of credit..lol. i figured it out and will be playing with it this weekend..I will post up results..thanks again for all your hard work figuring this stuff out and sharing your file for the rest of us to reference off of.

jeez man gimme lil bit of credit..lol. i figured it out and will be playing with it this weekend..I will post up results..thanks again for all your hard work figuring this stuff out and sharing your file for the rest of us to reference off of.

Well Im serious, alot of work goes into a standard tune let alone a modified boost-a-tune.

Just dont want to hear a bunch of "well I loaded your file and blew up my motor"... and when you cant tell a differerence between a LT1 file and a Tunercat file that's the second thing I expect a person to post.

So just take it easy, make sure boost starts low and stays low, make all timing low and increase slowly, and nice rich fueling to make sure things are reading correctly, then start tweaking.

1992 supercharged corvette here, running 12lbs boost with 60# Siemens injectors and alky. Currently a 1Bar tune, very rich in boost because it isnt dialed in right. I'm planning on trying a 2Bar tune to make dialing in the boost easier.. I'm assuming all the principles in this thread are the same for a 92 SD Y-body?

The only thing I am concerned about is the min PW which in my current tune is set to 0. I guess I'll go with it for now, and look out for issues described earlier with PW less than 1.0.

As an aside, this morning I emailed TC for a Baro-reset version of $DA2; and within 5 hours I have it!

I'll probably post back here with progress. Thanks for an inspiring thread!

Andy

A possible contribution to the body of knowledge in this thread. The latest version of DataMaster has a set of comparisons of voltage vs MAP for GM Map sensors (1, 2 and 3Bar) in the help files. I loaded these into a spreadsheet.

VERY INTERESTING: when comparing the 1Bar and 2Bar sensors, for a given voltage the scaling isnt exactly 2x. For example, at 1.998volts, the 1Bar sensor will be detecting 48.1 kpa; the 2Bar sensor will be sensing 60.63 kpa, which is only a scaling of 1.3x, not 2x.

In fact (and I would like someone to check my work - see below for a link to the spreadsheet), the 2Bar sensor delivers the same voltage as the 1Bar sensor at 30kpa !!

1Bar 2Bar Comparison (http://www.scandepot.net/viewscan.php?pk=5936)


I hope this is useful - if correct it may help speed up the tuning process :)

See above; this also has interesting implications when scanning the car (I think). Using a 2x assumption, if the scan shows data at 50kpa (i.e. the sensor is sending 2.1v), we were assuming that the car was actually at 100kpa. IN fact - the car is "only" at 70kpa. I dont think it hurts tuning, because the ECU will be looking up the 50kpa column and that's where we would ajdust VE. But I wonder if it impacts decisions regarding onset of PE / etc.

All this is making my head hurt. Comments anyone?