- Joined
- Mar 22, 2017
- Messages
- 285
I am working with Lund on updating my tune after adding a wastegate (@ 10 psig spring), upping pulley to a 3.33 (~15-17? psig without wastegate), ATI harmonic balancer, MMR OPG and CS, and offroad h-pipe.
The fuel from 3500-6000 RPM has been a challenge. Originally lund thought no tune updates would be required from my previous tune. We noticed lean/high STFT in this range so he added 15% fuel. Now, new datalog and it helped the AFR (peaks around .86 lambda instead of ~.9 before) but the STFT went way up (peaks around 1.15 now and was 1.10 before). What is interesting is that the STFT and AFR both clear up when we get close to redline because it was originally tuned at ~10 psig at redline.
To me that says its a tune issue not a mechanical fuel issue, it would be worst at high RPM (max fuel demand). Something is definitely confusing though.
Any help appreciated.
The fuel from 3500-6000 RPM has been a challenge. Originally lund thought no tune updates would be required from my previous tune. We noticed lean/high STFT in this range so he added 15% fuel. Now, new datalog and it helped the AFR (peaks around .86 lambda instead of ~.9 before) but the STFT went way up (peaks around 1.15 now and was 1.10 before). What is interesting is that the STFT and AFR both clear up when we get close to redline because it was originally tuned at ~10 psig at redline.
To me that says its a tune issue not a mechanical fuel issue, it would be worst at high RPM (max fuel demand). Something is definitely confusing though.
Any help appreciated.