I have a PTE 52 with a CAS V-4 and 009's. I run 21psi with 23 degrees of timing. I run mid 7's in the 1/8 at 96mph. I have talked with Joe at PTE about my combo and he says 24-25 psi is were they really come alive. Before I do that I gotta get 50's. Hope this helps.
Ditto, My car was 1 tenth per psi from 19-23 From 23 to 24 it gained almost 2 tenths. It was effeaiant up to around 27 ish on my motor. But depending on your heads will determine the the "sweet spot" of any turbo.
