Originally Posted by
velociabstract
I'm close to sea level and mine will reach 19 peak psi with just a 178 crank pulley. It sounds like you have some belt slip to me even though you don't think so.
Les
Or slight intake manifold leak or leaks towards peak boost; even if he doesn't think so. OP; Have you had your intake manifolds off before, and how did you test your charged intake tract?