stop detonation? you have a few options: higher octane fuel (people already use 110, can't go much higher); lower compression ratio, but this will cause a drop in power and/or an increase in fule consumption, but having said that, maybe only 0.2 is enough; cooler heads, ie, water cooling, been discussed a lot already, and lastly, different design heads, which is well beyond us average engine users. Thoughts?