Originally Posted by mlbbaseball
IF my logic is right, then a DI car can run a bit higher A/F ratio cause they can keep the temps cooler?
your logic is right, MS3's are often tuned to about 12.6 even at 22+psi...
start googling there is a LOT of info about the ideal max torque afr of different types of engines.
And then there is the real world which usually differs from that info, where single cam mustangs love to run at 12.6 but the NA 4v motors can get up above 13, and where turbo zetecs can be under 11.5 and still be happy.
bottom line is you have to either get on the dyno and figure out what works, or beg for the experienced opinion of a nice gentleman (sometimes named Tom)