perfect air:fuel ratio

[madwilly240]

I read that 14.7:1 is the perfect air:fuel ratio for gasoline to combust. Do most cars have that ratio? or is that why people get air-fuel controllers.

[Foxcolt]

That's good for stock.

BUT once you get into high hp land the correct a/f ratio at full throttle is usually around 12 to 1.

A very talented tuner once told me that if your car isn't pouring out black smoke at full throttle then it's running too lean:D

[d240t2]

14.7:1 is good for emissions, not for power. Peak power is usually around 12:1 (rich). This is true stock or not.

[Phlip]

14.7 will also cause a very high temperature with such a lean ratio, I agree with dennis, aim more towards 12, you'll be less prone to detonate with that too.