Its all about dynamic compression ratio, BB. Even though the static compression ratio is high, the dynamic is down in a reasonable range. On my big SOHC DCR is about 9:1. This is pretty high for pump gas, but with the EFI system I can run a street tune that is a little richer and back the timing off somewhat, and that makes the engine completely livable on the street. Then I can change tunes at the track, fill up with 110 octane race gas, and get the performance back.
