A\F Ratios..

[CrazyM]

Air/Fuel Ratio Limits
6.0:1 Rich run limit
9.0:1 Low power, black smoke
11.5:1 Rich best torque at WOT
12.5:1 Safe best power at WOT
13.2:1 Lean best torque at WOT
14.7:1 Chemically ideal
15.5:1 Lean light load, part throttle
16.2:1 Best economy, part throttle
18-22:1 Lean run limit

So from doing some reading and such, most people go for a 11.1 ish A\F ratio, which according to this chart is Rich best torque. to make a few extra HP would you not want to want to lean it out a bit to 12.5? Or is that chart more referring to a N\A motor and we run the 11.1 to compensate for pumping in air through the turbo?

 

[viperlp01]

Ya, I think those numbers are for an N/A motor. You can run the 12.5 if your running some race gas... Its just a really lean condition on pump gas that is adding to the emense heat that a force fed engine already produces... I run about an 11.5 a/f on 93 pump at 20psi out of an e316g with a fmic... It loves it but any leaner it starts to bog(knock) so i stay around there...

 

[rstchris]

All engine setups are ok 13.5 wot but when you add boost your brake specific fuel consumption goes up. You should not go leaner than mid 11 on pump wot. ^^^ Like stated above, you can run 12.0-12.5 on corn juice or 100+ petrol.