[darkpuppet]

the zetecs respond pretty decently with a 12:1-ish ratio.... you basically want to tune for as lean as you can without creating excessive cylinder temps or pre-ignition... so the closer to 14.7, the more power you're making... but if you ping, you're dead... so that's why people aim to run richer.

With the zetecs, if you want to keep your cylinders cool enough to prevent pre-ignition at higher revs, a 12:1 ratio is pretty decent. Granted, 12:1 is assuming pretty standard pistons, and boost pressure.

but 10.8:1? That's nearly black smoke territory...