Really converting the lt1 pcm to see boost.. INterested?

Hello guys...

I was toying with the possibility of looking for pro help to change the lt1 pcm's code to actually see bost with variables similar to the $58 ECM (syclone) and some additional tables that I think are useful for us...

I thought if
1)Removing the MAF limitation
2)rescale the tables to accept a 2 bar map sensor
--a)Timing and VE tables
3)Change the parameters as to 100kpa is to the pcm related to the map sensor
4)add a IAT vs timing table (which i believe it has)
5)add a PE enrichment vs MAP table or and a few other goodies...

I was quoted in the vecinity of $5k-$10k for this proyect... maybe it can be done.. maybe it cant...

What do you guys think about this?

If we could get enought people that use the stock pcm we could do a "group purchase" and have this job done that will benefit a LOT of people inside the community...

Let me know what you guys think about this. Worth it or not?

I have another theory we are testing...using 3 bar map and APex S-AFC. Should be alot cheaper....

Jose

How is this?

Wouldn't it be better and cheaper just to use an aftermarket system?

I don't want to let to much info out. But it will use an external 3 bar map sensor in its own case, and dedicated fuel computer. No laptop, no software...etc. It will be soley for controlling fuel. Timing we will leave up to LT1 edit, since their is no reason to re-invent the wheel.

Jose

Chad, every priced out a FAST system even without the wideband??? Its over 1500, and DFI 7 is a little more if I remember correctly...

Jose

I kind of figured they were in that price range Jose, but I guess it depends on if that $5k-$10k price quote was for the initial engineering and then what it would be per unit for a group purchase.

If a wideband could be added to that list I think it would be better.

Not to mention with a DFI or Fast you have to spend time and cost to tune it if you cant yourself - and that takes a LOT of work.

Using an S-AFC would be cool, but I dont know how much play you'd have in the variables... I love those things, but dont know how well it'd interface.

Anything about using the stock ECU, I'm all over it like white on rice on a polar bear in the middle of a snowstorm.:D

Geoff, you will like what we have then. ;) And yes it will still use the stock ECU and be under ~600.

Jose

look up megasquirt.

full independant control of the fuel delivery. 3 bar map built in. Stand alone. ~$150 bucks in parts. Program it yourself.

Originally posted by Tiago
look up megasquirt.

full independant control of the fuel delivery. 3 bar map built in. Stand alone. ~$150 bucks in parts. Program it yourself.

I know about megasquirt- A friend of mine is using a custom tablet PC case for it and all sorts of other things. But he's a programming nutjob, and I'm not, and he doesnt know much about piston engines- His car is a 4-rotor 2.6L - and he's looking at turbos :shock:

I've seen the megasquirt many times, but it has limitations, and unless your well versed in assembly, its not easy to redo maps for it.

Jose

If you can program the megasquirt you can redo the tables on the lt1...

Anyways I will keep researching this...

I would be very interested in this... hell even getting some info on the Harlen's setup and how he managed to successfully run two MAF's in parrallel would be great so you could get away without maxxing the single unit.. this should give you much more accuracy with the fuel curve fueling! but if that is the initial cost for the engineering then that is not too bad.. just have to figure out what it would cost in parts and what exactly would be needed to be able to replicate it after it has been worked out on the prototype. but yes keep me posted!

Chris

I think it's just a matter of disassembling the OS on the flash, and rewriting certain parts to make use of a 2 bar or 3 bar map sensor. Not exactly an easy task though.

Will the system have waste gate control?

The tables ARE on the syty so i guess that is not difficult to implement...

Originally posted by aboadnan
Will the system have waste gate control?

The egr vavle can be used as one if you program it to.

Originally posted by texanmutt
The egr vavle can be used as one if you program it to.

If you're saying use the EGR valve on the back of the intake manifold as a by-pass for boost, no it wont work.

You'd have the severe issue of venting air that had already been metered, and you'd run pig rich when it opened, and that would be more of a BOV and not a wastegate. Not to mention there's no way the EGR valve can flow enough volume to keep a decent turbo (or pairs) from over-flowing the manifold as they continue to spool. Also as the turbos over-spool they will drop out of efficiency range and your IAT's will rise even if the EGR valve could keep the boost at a controlled level.

Use a boost controller for a boost controller to control the wastegate by the vac. lines. That will get your boost under control the right way - dont use something that wasnt meant to do that play such a critical role in such a delicate job.

Also IMHO you dont want the ECU saying how much boost you run, unless it would have it's own kill switch (like a vac solenoid that would close before the boost controller's input and manually force the boost to a lower level (like 6 or 8psi, maybe even 4...) and then use your boost controller to make the adjustments. Your ECU cannot account for changing road conditions effecting traction, and also what you are feeling like doing with your vehicle.

I'm looking to run 12-14psi on pump gas on the street. I wouldnt run that much normally because 1)it's too much power 9 times out of 10 and I'd spin my 315's to oblivion and 2)because I just dont need that much power to murder anyone who wanted to race me.

An in car boost controller would let you adjust the boost to what you want at a moments notice. There are a lot of things I say "leave up to the ECU" but there are are some I dont.

Not to sound like an Apexi freak, but after years of using the S-AFC and the AVC-R, I am more then willing to see what they can do for us. Very good tools for moment's notice adjustment, they have a great interface, and have built in gauge functions. Not to mention they can be found on ebay for a decent price.

[/poor english skills]
It's too early in the morning for a Sunday...

Originally posted by texanmutt
The egr vavle can be used as one if you program it to.

I meant the soleniod, which is the very same soleniod used to control the wastegate on the GM 6.5 turbo diesel. In which case you can "in theory" ( case this whole thread is all speculation) program the egr output to control boost levels.

its all speculation but it can be done... i have a quote right now for 4k!!! :(

http://forums.corvetteforum.com/zerothread?id=547494

:eek: wow:eek:

Those guys in that thread seem to be talking a little over my head:confused:

I am real curious what will develop here, I have been researching how to deal with boost for when I finally have enough $$ to buy some.:D

Is this $4K for 1 computer, or is this with the capability to duplicate for a lesser price. How would one edit the tables of this new PCM, and is software available with this price to edit the new tables?

its 4k-5k to develop the bin.. after that it can be duplicated..


I would create a definition in tunercat for it.. so it would be a lot easier....