Finetuning

[Corv1-Micke]

Hi everyone,
I´m a Corvette owner from Sweden.
I will try to finetune my Corvette -91, 6-speed, with a 434CUI Lingenfelter small block. Running the stock ECM with chip from LPE.
Doing some changes on the engine right now, and will try to tune a new chip with APU1 kit from Moates. The biggest change is from 32lb @ 50psi to 42lb @ 43,5psi injectors.
Have also a wideband lambda that I will try to connect to the Autoprom for logging.

I will look around in the forum, and try to learn some. Will start up the engine later this spring.
But if you guys have tuning suggestions for me right away, please post them

/ Micke

[dave w]

I have used the attached "8D VE Correction Log File Analyzer" to tune a Corvette like yours.

dave w

[Corv1-Micke]

Thanks Dave.
I see what you have done there (I think), and that I already have to learn a little more of the TunerPro RT software. So far I have only "offline" read the original -91 chip and the chip from LPE to bin-files, just to try to learn where to start..

The engine ran to lean before. The result was piston rings running to hot and broke.
I will install new rings and a new fuel system (bigger fuel pump and injectors).
Injectors will be Lucas 42lb. The old Bosch 32lb was running at 50PSI, but I will try to work at standard 3bar (43,5PSI) with the new ones.
Fuel pump will be a Bosch -044. (yes, I think I will have to do new electrical wiring to this big pump. Will need about 13-15 amps...)

Does the "Injector Flow Rate" and "Cylinder Volume" Scalars-parameters in TunerPro affect something on the actual fuel/air mix? (does the ECM read and use this information at all?)
Hmm, guess i will start a thread at the correct place at this forum when I´m ready to start up the engine and do some logging and tuning.. :)

/ Micke

[dave w]

Does the "Injector Flow Rate" and "Cylinder Volume" Scalars-parameters in TunerPro affect something on the actual fuel/air mix? (does the ECM read and use this information at all?/ Micke

Yes.

I have used the "1227727 Corvette" computer to operate a 1998 Vortec 454 fuel injected engine. I am curious, there might be a limit on how "big" the injector flow rate can be? I personally have not tuned a "1227727 Corvette" computer with "big" injectors like you are going to use. The Vortec 454 I set up with the "1227727 Corvette" computer has the original factory 19lb injectors, which leads me to the conclusion the "Cylinder Volume" will affect what the computer does with fuel / air mix. I don't know if there is design limit of "Injector Flow Rate" scalar, maybe there is a maximum injector flow scalar, I don't honestly know. Maybe at the time the 1227727 was designed, the designers where thinking the biggest engine in production at was 7.4 liters and the biggest flowing injectors was 24lb / 28lb / ???, which might limit the maximum injector pulse width?

A new thread when you get ready to start the engine is a good idea.

dave w