Kamaro

I just swapped in a LSA out of a 2013 ZL1, I added a 2.55 upper pulley and a LS9 camshaft, I hooked it up with a stock CTS-V PCM and a stock tune, sure enough it was very lean because of the extra air. I'm trying to learn my way into PCM calibration so I got myself HP Tuners and trying to figure my way through it, I started by data-logging while driving around and saw my STFT - LTFT are way high and the AFR is around 15-16 cruising and 13-14 WOT, I added 20 percent to the MAF calibration table and that seemed to help a bit but I found that the STFT/LTFT numbers were all over the place!, can someone please guide to where to start to get a decent AFR?? I saw a nice youtube vid about tuning the VE by data logging the STFT graph and then copying the differences to the VE table, that seemed to get things much worse!!, any guide/hint would be highly appreciated.

Thanks,,,

baronsmith98

iTrader: (2)

I'm not near my computer to look at the tune or log but did you change injectors? If you have incorrect injector data you will chase your tail all day. Any other mods? What OS are you using? I will try and look at it in the morning when I get off work

Kamaro

The injectors are the stock LSA/ZR1. Two main mods has been done to the engine, smaller upper pulley for the S/C (2.55) and a LS9/ZR1 camshaft.

The OS of the ECU is 12632176 , its out of 2009 CTS-V.

Darth_V8r

iTrader: (4)

If you only used STFT for adjusting VE, that is not going to help. Use LTFT + STFT to adjust. BUT that will only help at part throttle. At WOT, fuel trims are basically disabled. When you log, every time, rezero the fuel trims in the scanner

Your best bet is likely going to be using a wide band and AFR error to fix it. Run in open loop while using the WB.