Hey guys i just put a set of them Comp Cams 980's in my car and now i cant run 15 PSI of boost with out alot of knock, im running the 91 Poston chip stock turbo aftermarket fuel pump fuel reg. boost gauge tach, I have been told the poston chips are junk is this true? what chip should i get? turbo tweek caspers what? please let me know what everyone has in theres and what has made there car come alive.