I have a 2002 Camaro SS with a 408. I purchased and installed a rear mount STS system 80mm turbo. I know that most people don't care for the rear mount but I chose the rear mount because I didn't want to delete the a/c. Car is to clean and only has 15 miles on it. My issue that I am having is no matter what size spring I put in the waste gate it will only boost half of that spring or almost exactly half. example 5lbs spring 2lbs boost, 10lbs spring 5lbs and a 15lbs spring at 8lbs boost. We have pressure tested all the piping and show no leaks. We did a boost test at the compressor and it reads the same as the boost gauge. We have talked about putting a e-boost2 system in but we don't really want to put a band aid on the issue and would like to find the actual problem. Any suggestions?

 

Spring rates are just suggestions. You get what you get, and then use a boost controller to bump it up. You will get faster spool with a boost controller instead of letting the boost just blow open the valve all the time.