Originally posted by MikeWRX-NJ
i can speak from experience.
I HAD P&P vf34, gruppe-s headers and all supporting mods.
max boost of 17psi @ 3600rpm.
I HAVE P&P stock headers (thanks Nino's AutoAccessories!) and same supporting mods.
max boost of 17psi @ 3300 rpm. I hit 10psi at 2900 rpm.
Were the gruppe-s coated?
Iron > steel for turbo headers.