E40 pointers for a newby

[Dan66]

Hi All,

I've been scanning through posts and reading as much as possible on the E40 ecu. I am looking to work through the tuning of a VXR (UK spec of HSV coupe/GTO). The 6.0 LS2 has a full exhaust, Trickflow 550hp kit (heads and cam), FAST 102 intake, otrcai mafless induction and higher flow injectors. Gearbox is T56 manual, diff is 3.91.

Looks like Gelf VXR produced some extensive material and guides on this engine/ecu however, the links do not look to be working any longer.

If anyone has any copies of this work or any other details that will assist in working through this process, please post links or email me on daniel@cinetech.ie.

Thanks,

[joecar]

Have a read of post #1 here: Calc.VET thread

[Dan66]

Hi Joe,
Have read through the full thread, while very useful, I'm not fully clear on how to translate this info to building a mafless tune on an E40. Do you have or know of any available 'pre-built' files to do the scan - filter - calc, process that will jump start me into building the VE table. I understand the concepts and what is being done and an amount of the math behind it, I'm just getting stuck on some of the setup terminology to allow the process to be done. I'm sure once I see some of these it will make sense.

Any other pointers greatly appreciated.
Daniel

[joecar]

Since you will be correcting the VE table, then you want the Calc.MAFT procedure (not Calc.VET) and you will be ignoring the MAF calculation part of it.:
Calc-MAFT-correcting-VE-and-calculating-MAF-(in-single-log)-gt-reverse-of-Calc-VET


First you have to find which other equivalent pids the E40 has.

Then you will do the Calc.MAFT procedure to correct the VE table (if you have NBO2 and WB, use CALC.SELBEN), and you will ignore the calculated MAF table part of the procedure;

if your NBO2 are disabled (i.e. you run OL always), then use CALC.WO2BEN instead of CALC.SELBEN to correct the VE table.

Note: CALC.SELBEN uses both NBO2 and WB; CALC.WO2BEN uses WB only.

[rpmauto]

Joe,
we were going to do this a few different times. Never really got around to it. Life has gotten in the way and have not done much tuning the past year or two. (well been doing a bunch of diesel, but not much gas stuff). I still have never cleaned up the wifes tune on her GTO. I would like to keep tabs on the original posters progress and see what he comes up with. If it works I may have to give it a go when time allows.

[joecar]

No worries.

[Dan66]

Did a couple of runs on the dyno tonight and still on the steep learning curve. Anyway, am I correct in understanding that the VE table is referenced againgst the AFR sample (WBO2)? You keep tweaking until it is within the +/- 1% range, so rather than a true measure of the VE it’s a reference VE for fuel:air that matches injector deliver to cylinder fill at that cell? If you did in fact know exactly one or other value precisely, say injector flow curve, then you would in fact have the true VE.

If that is the case, what determines the AFR the VE table is calibrated to? I would have thought you would tune the VE to an AFR that delivered most power/torque, tune the timing to max power and minimal knock, then add PE to calm the knock rather than pulling timing. What sets the reference AFR prior to setting VE and can you then lean that setting out to chase the best power curve?

So to do that you could prepare say 10 tune files, flash, do a datalog, flash the next, etc, etc, compare all the curves for the 'theoretical' best pull, blend the sections of each tune that would have produced that result and you should be optimised. Ditto for spark.

obviously lots of other factors to trim as well like timing the injector to valve opening, etc etc. None of which you can do until you have an accurate VE and AFR.

If you see an overall rich WBO2 signal, do you adjust the VE table to lean it out or do you alter an injector parameter?

[joecar]

No... the concept is even simpler than what you said...

VE is used to compute cylinder airmass... (with trims disabled) the wideband measured AFR is compared to the commanded AFR, and the ratio is the correction to multiply the VE by

i.e. with all trimming disabled, the ratio of commanded and measured AFR's is an true measure of how far the VE table is from actual.


Same principle when correcting the MAF.

[joecar]

The AFR is stated in the OL fueling table B3605 (or B3647 for COS).

[joecar]

You correct the VE table... the AFR you use is not important (other than it be sane).

Then once your VE table is correct, you do additional pulls to find the best AFR and timing (this time leaving the VE table alone)...

also note you try to find the least timing that produces the most torque or power without knock.