Originally Posted by smack

i disagree. my car has a rather loud HKS cat-back with Invidia downpipe, and high flow catylitic converter (3" from the turbo on back) and i love it ;)

it sounds like a baby ferrari when it revs, and with the new computer tune i am running produces about 50 more wheel horsepower from the stock setup.

i don't think the bimmer would gain that much with just a new exhaust, turbo cars make bigger gains with better breathing over an N/A setup, but it will certainly make a nice difference.