i didn't see you post when i posted mike. obviously, i totally agree with you. personally i think doing anything besides mufflers (and that's just for sound) is a waste of money on our cars. the NA cars just don't respond well.

 

A 5 HP gain is for the airbox only. A quality set of headers, catalytics & mufflers, such as AWE, should be good for about 20 HP. There was a long thread on the rennlist 997 forum about this, documented with dyno runs. ECU reflash good for maybe 5 more. A total of about 30 HP is the most that can be expected, unless more elaborate & expensive intake, exhaust & reflash kits are used, such as 9ff with new camshafts & $15K parts cost.

From the propaganda out there, it looks like a supercharger kit combined with a complete exhaust system should make well over 500 HP crankshaft & 450 at the rear wheels for an installed cost of $20K.

At that price, you are probably better off going with a new turbo, unless the sunk cost in the car you already own makes the work cost effective. Do a basic cost/benefit analysis to determine if it makes sense. Numbers can vary considerably, depending on the assumptions made. In addition, heavy modifications void the warranty, less than 4 years old, be certain what you do.