I was going over some data logs and noticed that my 3rd gear AFR ratios are in the 12's for the most part. Once I go up to 4th gear, the AFRs get down into the 11's. Are the lower gears (1, 2 & 3) supposed to run leaner than the higher gears? If so, what would be a good Air/Fuel ratio for each gear? I'm non-built running the APS single turbo.

 

12's at lower RPM, and WOT are fine, but I'd like to see your AF ratios dip into the 11's beyond 4000rpm. In gears 1 and 2, you are under much less load, so its not uncommon to see slightly leaner AF ratios, and obviously..less boost pressure.

 

sweet...