Originally posted by d00f
12.8 was the leanest I've ever seen with most of them targeting about 12.0. This is all assuming my lambda to AFR conversions are correct as the european tuners I've met and talked to speak only of lambda and bar whereas I can only think in AFR and PSI.
It just strikes me as being really rich when if I read this correctly, your really tuned and leaner than normal is running 10.7:1.
I'm wondering what sort of scientific approach was used to determine the optimal ratio. What was the ignition advance around peak torque? What method was used to find the optimal advance?
I'll post the maps from this tune soon. We strapped the car to the dyno and started working the advance up to ranges we were comfortable with. Each degree of advance increases torque up to a point where you gain almost nothing from extra advance.
10.7:1 is a good target for pump gas. It's rich enough to keep EGTs down, and also rich enough to keep your motor away from the detonation zone if you get a bad tank of gas.