Magnaflow exhaust
That thread is leading you in the right direction. Buy a cutout and have the car tuned with it open if you're gonna be racing the car/driving it 'spirited' this way. You could always close it on the street and still get on it, the car will just be more rich and make less power with it closed through the muffler.
granted im only a 3.8...but all the same principle....we were having turbo 3.8 guys gaining 30-40rwhp just by opening a cutout...and increasing traps in the 1/4 by 2-3mph.







