I am unsure about the compression ratio of my built a6/z6 mini-me. I have 9.0:1 compression pistons but the block and head were resurfaced and the machine shop cut ten thousanths off both the block and the head.

Right now im running 10psi but this month ill be switching to a t3/to4e and running 15-20psi. I am wondering if the compression ratio is going to be too high to run 15-20psi. Im guessing the compression ratio is about 10.0:1. I know the z6 head on the a6 block bumps up the compression but not sure what the outcome is since my block and head are shaved and that combined with my pistons. Let me know what you guys think.

 

TTT

 

Check out this link:

http://www.knology.net/~jediklc/D.htm

Your comrpession ratio is not too high to run that kind of boost, but you will have to be sure to tune it well

 

if ur compression ratio is 10.0:1 and u run 15 psi it wud put ur compression ratio up in between 11.0:1 and 11.5:1 depending on ur timing...every 3.7 pounds of boost raises the compression ratio up 1 full point...so on 15 psi ud be straight to run it on 93 octane gas around the street if u tune it rite and have the timing set rite but 20 psi's in my personal opinion is pushing it for pump gas u mite have to add some octane boost if u plan to drive that around on the street