View Full Version : how high up can i go in compression?

10-04-2004, 12:31 AM
hello, i have a 89 with 10% od pully. and free flowing exhaust. i want to know how high i can safely go up in compression on pump gas. i can mill them t work but need to know what to go up to. Thanks, jon

10-04-2004, 08:13 AM
Tim is running 9.8:1 in his. He's having some issues keeping the charge cool enough to run decent timing without detonation. I'm running about 9.3:1 with fairly good results. The guy who won Pro-Street at the shootout was running about 9.8:1 with obviously good results. He had a front mount IC which would help keep the temps down.

It's all relative. Detonation will be hard to control under high boost but if the rest of your setup complements the high compression, you'll be able to prevent it.