Here's the situation. I have TunerCat and a '95 T/A (mods listed below) I finished up a swap from an A4 to an M6 and re-programmed the PCM using a stock M6 bin file I found. However,
I have no clue as to what to do with TunerCat first. Anybody have any suggestions? Is there a website that explains what does what in TunerCat? I'd REALLY like to get into programing my PCM but I'm completely lost right now. I still need to do my LT4 head/cam kit swap too (that's why I got TunerCat ) Any advice or suggestions would be greatly appreciated!
Thanks!

'95 T/A M6, 3.42's, Moroso CAI, 52mmtb, !CAT, Ported/Polished MAF, !Air Pump, TPIS headers, Flowmaster exhaust

 

Start by adding 2 degrees of timing across the board. Then fix your Air Fuel ratio to about 13.2:1, if you look in Tunercats calibration help file it will explain the Foumula. Look at %change Air/Fuel Ratio Vs RPM at WOT, that is the table to make changes in to fix the A/F ratio at WOT. See how that works and go from there.

 

Unless you have a reliable method of testing changes you make, I wouldn't bother trying to tune the pcm at this point. A dyno would be best, or the track, if you can run consistently. There is really no point in tuning AFR without a wideband O2 sensor. And in many cases the stock timing is spot-on.

Since your maf has been ported, your car is already running leaner because more air is passing by for the same maf reading.

Please note that any AFR in the pcm is a calculated value and most likely does not represent reality. In your case since your maf is ported your car will be running leaner than the calculated afr. And once you change the heads/cam, all bets are off.

'Bout the only thing I did when my car had minor bolt-ons was lower the fan temps for my 160 stat.

 

You have to correct for the Ported MAF, add 20% to the MAF tables and then you have to correct the Checksum(use Tunercat Checksum tool) But you can not just leave the old Maf values and hope that leans the car out. If you want to tune your car the right way you have to make all corrections for things you change. Also correct the Air/Fuel ratio, If you make the proper correction when you change stuff (Injectors, MAF, ext..) the ECM will be close to the targeted Air/Fuel ratio that you put in it. In the 3 cars that I had on the Dyno, the Air/Fuel ratio was within + or - .2 of the targeted(13.3:1 Targeted- 13.1:1 WideBand O2 sensor Reading) If you do the calculations in your tables, you will see that the Factory settings are VERY RICH. Also the timing can be advanced. The Factory has to tune the car for a varity of varyibles, and that means you can taylor(Get more POWER) They have to tune for 89 octane fuel and if you only use 93 or higher you can turn up the timing. The factory has to be VERY conservitive whit there tune- You do not!! To sum up this long story you Can get gains without DynoTuning your car- I have done it!!! Just my 2 cents.

 

Hmmm...I'd love to know how you figured the A/F ratio using something in TunerCat that was pretty much right on with a wideband? Were you just changing the PE stuff?
Also, every A4 car I've done the stock timing curve has been pretty good.
On M6's, I've had to take quite a bit of timing out as they haven't been able to handle as much.

 

It's easy, Use Tables "%change To Air/Fuel Ratio Vs. RPM at WOT" combined with "%Change To Air/Fuel Ratio Vs. Cool Temp At WOT" These table along with the formula [WOT AFR = 14.7 / (1 + %Change vs Cool/100 + %Change vs RPM/100)]

This will tell you what the computer is Targeting for A/F ratio at certain tempatures. It will be pretty close (ussally within + or - .2-.3) The ECM uses this calulation along with ohter tables to get the targeted A/F Ratio. *Note- I have not changed the fuel Tables" I do not know if this will work if you messed with the fuel tables.*

You ask, how did he figure this out? I read the calibration help file that can with Tunercat. Than I tested it, by fixing the .bins and putting the car on a Dyno to check it.

I did this so I could pass the knowlage on to others!!!!

Hope this helped!!!

Almost forgot- If your timing was almost right on the money, it may have to do with the gas you are useing"Not that good" I was able to give my car a few degrees without any "Ping" I live in NJ and use 93 octain gas.

That is why our carsa get detuned at the factory- someplases "93 octain" will ping and some it won't. I got an extra Peak 20RWHP and up to 35RWHP in some parts of the RPM range.

 

Hmm.....so would it be better to just go back to a stock MAF? Can I go into the MAF sensor calibration tables and select all of them then use 'scale with value' and enter .2? (told ya I was new to this! ) I'm startin to think I should sell my car b/c this seems WAY over my head! You guys though

 

I know how to use the PE tables. I've made up a spreadsheet that does all the math for me.
What other tables do you think the computer uses to obtain this desired a/f ratio?
And what is this "other fuel table" you speak of?

So you have dyno proof that this formula does work? I've never really trusted it. But if you're saying that we don't need to use a wideband, we can just use this formula...I'm all for it.

WOW!! Just by adding a couple of degrees of timing? Or was this changing PE stuff too?
I put 93 in my car and the most timing I can run is about 34-35 degrees per datamaster. So that's like 31-32 in the actual table...since the computer is adding a mysterious 3-4 degrees. And that is quite a bit lower than what my stock timing map had. I think stock was close to 35-36 degrees. Lots of knock retard there!

 

Other Fuel I speak of= "Volumetric Efficiency Vs. RPM Vs. Map", "Volumetric Efficiency Vs. RPM Vs. Map (Ext.)", "AFR x 10, Open Loop Vs Coolant Temp. Vs. MAP" and if I am correct in thinking your Spreadsheet does not apply to the "Change To Fuel/Air Ratio Vs. RPM at WOT" or does it?

Not Saying you should not DynoTune, But I am saying you should tune EVEN if you can 1) Not afford Dyno Time to tune on, or 2) Be happy with a little better gains Vs. No gains from not Tuning.

My gains where by fixing the A/F ratio in the " % Change To Fuel/Air Ratio Vs. RPM at WOT" and adding 2 degrees timing in the "Main Spark Advance Vs RPM Vs Load" & "Main Spark Advance Vs RPM Vs Load (Ext.)" on MAP(Kpa) 90, 95, 100 between 3000RPM-6000RPM. THAT IS ALL I DID!!!! to get those gains!!!!

The car has a LT4 KM and does not get any knock retard. Cars are MILDLY TUNED FROM THE FACTORY because of the differences in the gas at different parts of the country and other variables.

You act like if you can't get something done the very best way, you shouldn't do it at all. Some people are happy with smaller gains that they can afford. I am not saying take my word for it, I am saying try it!!!

These Smaller gains are the same gains you get when you buy a mail order Tune. Not The best that DynoTuning can get you, but not to bad either.

Not all cars came with the same Tune in it from the factory. I have pulled a few "Stock" files out of LT1's and they have varied from car to car. Maybe you got lucky and you had one of the better files in your car. Other people may not have been that fortunate- like me.

I AM NOT HERE TO ARGUE WITH YOU, but to share my experiences with other board members- "Like the board is meant for"

You can take my examples or leave them- In the end I am happy with my gains, and happy learning more about programing the car to make it better. I like to Share what I learn with others, so hopefully they can get some benifits too.

One last note, I made these changes after talking to someone who tunes mail order cars and reading the Tuner calibration File. Read the Calibration Help file, it will tell you all about these "other Fuel tables"

Semper Fi

 

I thought the consensus was that the VE tables weren't used in a mass air car with a functional mass air meter?

I thought this table was only used when an open loop only program was utilized?

Sure does. I think there was a thread in here a couple of months ago where I was told that the 2 PE tables were the only tables used to alter WOT fueling. So those were the only 2 tables that I incoporated into my spreadsheet by using the formulas you gave above.

I definitely don't think that.
I've been screwing with 4 different LT1's for the last 3 months. One is a 93 w/ a 396 that we're having a hell of a time with, another is a heads, cam, header car that runs pretty well for what it has, and the other 2 are pretty much "stock".
So I definitely think that fiddling on the street can help quite a bit.
And not one of these cars has been on the dyno in the last 3 months

Me neither.

I have. See above.

 

[QUOTE]Originally posted by Dan K
[B]I thought the consensus was that the VE tables weren't used in a mass air car with a functional mass air meter?[B][Ouote]

When I messed with the VE tables the Wideband O2 readings Changed- That's why I put them back to stock.

I believe they are used in "open loop" The car needs some thing to base its calculations on , because it is not useing the O2 sensors in open loop.

Any ideas on how it does this?

Also I believe that if you run a log through VE master it will help with Part Throttle tuniing(have not dune that yet)

The only speadshet that I have seen is the "Virtual_AFR_WB_Calc" Whitch I have no idea how to use. Do you know what it does? Or how to use it, please explain how to use it.

Also the cars that you have been tuning, are not almost stock, they have big changes- so they should be DynoTuned. But a near stock car is preety easy to tune.

 

Really? Anyone else noticed this? Joe Georger...do you know anything about this?

It should be using the AFRx10, open loop vs coolant temp vs MAP table here.

That's the whole point of VEMaster...tuning the part throttle stuff to get your blm's in check. I've never used it on a mass air car, heard it's use is debatable. But I do plan on trying it on my car and seeing what happens. Can't hurt anything.

Never heard of it.

 

Here is what I know:
I ran VEMaster on my car, and it had no statistically significant effect on my blms. So their use in closed-loop with functioning maf is debateable. I never tried it on the dyno with a WB. However, I don't trust the up-the-tailpipe models, especially at low rpm.

Ed Wright claims the VE tables are closed loop only. He has some internal GM documents labelling them as such, and claims (via hardware testing) the pcm looks at them only in closed loop. I believe him. However, while the pcm may look at them, it may not necessarily use them. Perhaps it performs two parallel fueling calculations - one based upon the maf and another on speed density. If for whatever reason it thinks the maf value is suspect, perhaps it uses the speed density value, or some combination thereof.

Fueling in open loop would then be based upon the maf and the open loop table.

As a test, people on the lt1-edit list have zeroed out their ve tables to no obvious effect on the car.

 

When I changed my VE tables(only changed them a little) my tailpipe A/F ratio changed by .1 I assumed that it was because I messed with the ve table, but from what your telling me, I would have to believe that the different O2 reading was a result of something else.

On another note- How accurate is a tailpipe wideband O2? I was reading that The O2 must be close to the exhaust manifold to be accurate.

All in AllI have had good luck (SO FAR) with my A/F target ratio being close to the Wideband in the tailpipe.

 

When I went to the dyno last, my AFR at 2500 - 3000 was wicked lean, like 16:1. I don't believe it. It then went much richer at the top, which I do believe. This was with factory PE tables and a 95 calibration maf table - my car is a ram air and I found out later the maf tables are lower, which means the car will run leaner. I am going back to the dyno Sat, but not to tune. I might have a head gasket leak and I plan on going blown next spring, so I'm not sure what the point is right now.

I have heard of other people not even getting repeatable results with the tailpipe WB without making any other changes. Or people leaning out the pe tables and the resulting afr became richer.... However, these may be the exception rather than the rule, but irregardless I sure would like to have a wb o2 in a bung up near the engine.

The other thing I don't understand is that I have been told having cats does not affect the tailpipe WB O2. However, the factory uses front and rear O2's on 96 and newer cars to test the functionality of the cats. So the cats must have some measureable effect on oxygen content.

One of my winter projects is to get the DIY-WBO2 kit going and to compare it with the tailpipe WB at the dyno next spring.

Joe