I searched a bit and according to a SPDC piston set I was browsing at "If you are running pump gas a static 10.6 compression ratio is the limit to stay away from detonation. If your running a turbo or blower set up an 8.5 compression ratio is recommended. For racing, with race fuel you can move up to 12.5 compression ratio to maximize performance." Is this information more of a ballpark, or almost a fact? Just a little curious. Thanks.

 

I'd say ballpark, with the alum. heads 11.1 should be no problem.

 

def. a ballpark, and more accurate for older engines like the SBC. tuning is the key, and DCR has a direct effect also, but 11.1-11.5 SCR shoud be more of the upper limit for LS engines with a good tune ofcourse. and there will be exceptions on either end of the scale Im sure.

and, for FI engines, 9.5 is more typical. the higher the boost level however, should be accompanied by lower static compression ratio's. 8.5:1 would be more of a high boost application.