how to lower 9:1 compression

[1fast97gsx]

BAH there is a resion N/A's and Turbo's run diffrent compresion pistons. It's called pre detonation......................

Higher boost the lower compresion ratio you want!

9:1 would knock like a Mother trucker with 30 lb's...

I'd say you need to do some research. There are several members on here making crazy numbers on 10:1 and tons of boost. Granted these cars run race gas but your overall method of thinking isn't quite correct. Some turbos make more power at say 30 psi then they do at 35 psi since at this level you are overworking them and just pushing hot air. In this case a 10:1 motor at 30 psi will make more power than a 7:1 at 35 psi. It all depends on the setup, and the tune. I don't think there is a thing called pre detonation .... perhaps you are referring to pre ignition? Higher compression and high boost is always the best combination providing you can properly tune for it as your error tollerance margin gets very small.