Boosted E38 Help

[jnjprfrmnc]

Hi all, this is my 1st boosted E38 and kicking my rear, it's a turbo 2010 Camaro L99, a fellow tuner told me to tune through the MAF and the MAF curve is ugly now the idle is not to smooth and light throtle is a bit jerky after that it seems to run ok WOT AFR looks ok but like I said the MAF curve is ugly and around 5500 RPM seems to loose control of the fuel can not get the AFR below 11.8 checking the fuel presure in the AM, FYI 10psi, GT500 injectors, MAF is in a blow through 4" pipe before T/B, and no resinator in the exhaust other wise stock. Thanks for any help, Justin

[jnjprfrmnc]

They are putting in a boosta pump in now for the fuel issue, but no one has an answer to the MAF tuning question.

[odd boy]

Get me the file, please.

What AFR did you get @ wot? Post the dyno sheet if you have it.

[ringram]

MAF+Boost=Shit
Max airflow = 512g/sec

Answer=Delete

[odd boy]

MAF+Boost=Shit
Max airflow = 512g/sec

Answer=Delete

I’ve different opinion; we did many cars before with and without the MAF. It would be much better if he can get us the requested answers in order to have better look.

Especially, he is saying the idle isn’t good. So, he has other issues more than the MAF tuning!!!

[eficalibrator]

MAF+Boost=Shit
Max airflow = 512g/sec

Answer=Delete

I sincerely disagree and have 600rw, daily driven reasons why.

Some thoughts for the OP:

1) Did you use all of the proper injector data for the GT500 injectors? (recalculated short pulse adjust, offsets?)
2) Did you force MAF-only mode via RPM threshold and perform calibration of the MAF transfer function down low in steady state and under a moderate load?
3) Does your new MAF have a clean airflow entry that results in a clean, consistent signal when performing steady state testing? Bigger is not always better if you're getting noise. I have seen where larger MAF housings (I tried a 103mm before settling back to my current 90mm housing) gave me a +/-300Hz fluctuation that was all but impossible to dial in consistently. My 3.5" tube setup only sees about 11kHz at 67#/min airflow, so it has plenty of room to grow.
4) You better get the MAF curve right, since trying to dial in a VVT car on the virtual VE tables will keep you busy for a good, long time.

[odd boy]

1) Did you use all of the proper injector data for the GT500 injectors? (recalculated short pulse adjust, offsets?)

is there a way to find these data for any injector, because I do trail and error untill I get best tune!!

But for GT-500, I have them because I do tune ford engines

[eficalibrator]

is there a way to find these data for any injector, because I do trail and error untill I get best tune!!

But for GT-500, I have them because I do tune ford engines

Unfortunately, it's not as simple as copying the exact Ford values into a GM controller since the two OEMs have a different definition of exactly what point on the curve is the "offset". I went through the trouble of converting all the FRPP data a while ago and published the revised GM-specific values (corrected for 4 bar operating pressure) as part of my "GM Beginner's Guide" DVD. The DVD covers both the "how" and the "why" of these changes in the context of tuning an actual car using both EFILive and brandX software. There's a link to the Summit sales site for it in my sig since I don't sell them directly.

[jnjprfrmnc]

Sorry it took so long to get back here but efi is right on track the MAF signal is crappy idle in P/N 1200-1600hzand in gear is 1800-2200hz having them make a 3.5" charge pipe and thebap gave me control of the AFR and yes all the correct injector calc are there.

[odd boy]

Sorry it took so long to get back here but efi is right on track the MAF signal is crappy idle in P/N 1200-1600hzand in gear is 1800-2200hz having them make a 3.5" charge pipe and thebap gave me control of the AFR and yes all the correct injector calc are there.

I didn't understand!!!