I have a strange problem with my LT1 Camaro. A brief run-down of parts is: 363 cid LT1, AFR210 heads, 224/236-114 cam, PT-76GTS turbo, 450 ci water/air intercooler, home-built piping.
The way it WAS: 21 psi boost, through full exhaust including 3.5" piping over the axle and a 3.5" Hooker...