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?