What is everyone using for their engine management and what is your setup?

How versatile is the factory computer for forced induction applications? I would rather program the fuel in the computer than use a fuel management unit like Procharger has. I haven't noticed a lot of discussion about this, so I'm curious to see what everyone is using and how successful they are.

 

Sorta depends on how wild the engine set up. For most street applications where boost is on the mild side to even 14 PSI. I have used the OE ECMs such as what comes in a 94/96 GM PCM. A few here has even made them a speed density only strategy with a 2 bar MAP sensor scenario. Some has even converted to a 7749 ECM from a SY/TY truck, this allows GM factory Boost control via a native boost strategy from GM. This has been done with good success on F and Y bodies.

Many have coverted to the aftermarket FAST, and Accel DFI systems for aftermarket standalone fuel management. While these are robust controllers, one must realize that one just can't cut out the factory PCM or ECM without any consequences. For instance the digital dashes communicate with the in car CCM which talks to the PCM or ECM depending on what model year your car is. When the brain stem is removed the CCM has no one to talk to, then the MPG display stop working, and in some cases other displays as well, such as speedometer and HVAC functions. These problems can be avoided with a piggy back harness allowing the GM PCM to remain in place and talking to the CCM. The standalone systems offer flexibility in that they can use low Z injectors which are necessary for large capacity fuel needs when high boost levels are encountered. Plus they are fairly easy to tune with live tuning tools via a laptop.

I recently tuned a 2005 GM Truck with a 8.1L big block with a rear mount STS turbocharger system. It made about 8 PSI of boost and the engine made 425 RWHP with 560 Ft/Lbs of torq. At one point before the boost was under control it made 500 RWHP and 615 FT/Lbs of torq But that was at 14 PSI, where the old 8.1L would not live. All of the fueling was done via larger injectors and the factory PCM.

 

I would say anything 1990 and newer is really OK with good amounts of power and boost.

I have a 93 and its running a good amount of boost at the moment and drives absoulutely wonderfully with 65lbs injectors.

 

Actually, the Procharger FMU, for what it does, works pretty well. If you are running one now and your car is making good power and your AFRs are where they should be, I would fix what's not broken!

In the above post, I took it that he's running 65# injectors on a stock ECU. You can get custom high-z injectors in that size (kind of pricey) or you can get a low-z converter (if you do a search you can find them)--I'm not aware of any off the shelf 65# high-z injectors.

I run an upgrade MAP sensor, Gen VII, WBO2, and 84# injectors...my only advice is, don't buy what you don't need. Most C4 folks trying to make high boost have more tuning issues related to belt slip than to ECU problems.

Good luck!
CT

 

ps: 60/65# High-z FIs... http://www.racetronix.com/L107FM.html

 

Well, what I'm working towards is a twin turbo setup which makes the integration of the factory MAF almost impossible from what I can tell. I was planning to run 14 psi with a relatively mild engine (built bottom end, but mild cam etc).

 

I would prefer to stay with the factory ECM and work with it if at all possible. If it is not something that will work effectively, I'll save the turbo's for another project.

 

Not true mr dave, I force feed my maf (after the turbo), like alot of people do. Works fine. You place it inches from the throttle body, just make sure that you BOV is BEFORE the maf. Otherwise it stalls all the damn time in between shifts and after you back out of it.

 

Interesting. I thought the MAF would have to be prior to the turbo so that it would yield an accurate reading because of the higher pressure. If the MAF can remain in place, that would simplify my plans even more. Thanks for the info.

 

If you're looking at running the stock ECU and need to convert over to low-impedence injectors you can also use an Accel VIC (variable injector controller). I mention this because I have one for sale... But it will work with the factory ECU and allow low-impedence or high-impedence injectors and also give you individual cylinder control +/- 25%. I used it in conjunction with an old Gen 6 DFI in my blown/BBC boat.
-Jeb