I'm just in the process of having my '7 Turbo engine rebuilt and am wondering if anybody has changed out the standard 'plastic' intake manifolds - which run between the plenum chamber and the cyl. heads - for the GT2 metal versions, and with any measured improvements?

These manifolds come cheap direct from Porsche, so they are no big ticket item compared to what I've spent so far, on upgraded components.

Fabricated & coated headers, reworked & coated turbo's, intakes, plenum & larger throttle body, larger & coated IC's, alloy water radiators, oil pump and billet crank pulley, etc.

p.s. In UK we think you guys never drive in the rain or on winter roads as we cannot comprehend how engine shots from USA look so clean and NO corrossion!

what is your power target?

I'm running my car with plastic intake, gt2 intake didn't work with my cams. over 5k rpm power was falling even with higher boost.