08 Corvette Procharged. Fueling problems

[rpmspeed]

I have a 08 corvette. p1sc procharger. Lingenfelter gt9 cam. american racing long tubes and mid pipe. has fast 50lb injectors in it and I can't get the full throttle fuel consistent. I think my fuel injector tables is set up alright. Its only making 3psi of boost(need to get smaller pulley) Full throttle it won't go below 14 air fuels and leans out. I'll add some to the maf table than it'll go pig rich and barley subtract from it and go way lean. Also likes to break up mid throttle low rpm to full throttle. I've done plenty of higher power build tunes but seem to can't figure this one out. The cynair g/sec seems odd to me as well.
Just posting to see if anyon wants to look over the tune and a log see if i've messed something up. Don't have a log of the wideband its through the dyno and used a new sensor and calibrated it twice just to make sure. but WOT is 14:1 and rises up gradually past 4k.

fuel_0009.tunLog_0016.efiLog_0015.efiLog_0014.efi

[minytrker]

The breaking up is from being lean or you have a cracked plug. I didnt see listed a bigger fuel pump or a boost pump. Your probably maxing out the stock pump.

[rpmspeed]

Ok we'll try a boost a bump I just wouldn't think on 3 psi it'd max out the stock pump. Has brand new ngk tr6 plugs in it gapped around .035. sometimes it'd richen up below 10.5:1 throughout the run than really break up. Its just not consistent.

[minytrker]

Oh 3psi total, I miss read thought it was having issues at 3psi. It should handle 3 psi fine. If its 10.5 or richer its basically dumping fuel in it, to rich is just as bad if not worse than to lean. Are you tuning the VVE or MAF only? Do you have the injector data correct?

[rpmspeed]

I attatched the tune in original post with a couple logs. I want to say the injector data is correct. I have not touched the vve

[minytrker]

I was on my mac so I couldnt open it. I switched computers and looked at the tune. IMO your injector isnt correct, which is causing part of your problem. The other thing that jumped out was your adjusting the MAF and not the VVE but its still set up to use both. Also at WOT your commanding 11.0 from 3840rpm and higher. I would first fix the injector data, then turn off the MAF and adjust the VVE. Once the VVE is good turn I would switch it to MAF only and dial the MAF in. Once thats done you should be able to turn on the VVE and MAF and make any fine adjustments if needed. Without a WB hooked into EFI Live so you can log a/f its going to be really hard to dial in your fuel just from the dyno WB. I'll look through the tune better tonight, those were some things that jumped out at me.

[swingtan]

you're pulling 6% fueling via the LTFT's.....

Well, -6% in log 14, -8% in log 15 and -7.8% in log 16.

That's not going to help.

[joecar]

What FPR are you using, is it MAP-referenced or not...?


If your FPR is not MAP-referenced, then two things:
- your IFR is wrong, at 400 kPa it should be closer to 7.3 g/s (heptane test fluid) or 7.5 g/s (octane);
- your IFR will hit the max IFR 7.999 g/s at 480 kPa;

So you will either have to run a MAP-referenced FPR or scale all the air (MAP, deltaMAP, airmass, airflow) referencing/producing tables.

[rpmspeed]

its factory fpr so not map referenced. WOT I still can't get below 13 afr, i've messed with injector data, maf, fuel pressure table, I can't get fuel. Its to lean. Smaller pulley arrived so we put that on now its around 5psi. Made 498hp at 5500 but lean and I let off because it wants to go even leaner. VVE tables to my understanding don't affect wot higher rpm than what table is set for to come out of it. I'm kind of lost. Procharger claims stock fuel pump is good for 550hp, also can't find any data for the fast 50# injectors, so was using the injector flow rate excel charts

[rpmspeed]

Ordered a boost a pump today. Did some more testing and narrowed it down to fuel pressure dropping. Talked with jeff at lingenfelter (dealers and good friends with lingenfelter) and said his first start would be a boost a pump as well, so will try and that see what happens.