b6/b7 s4 exhaust question

[ILUVTTS1]

Hey, how's it going guys, probably a dumb question here so get ready...

Anyway I'm going to finance a b6 or b7 S4 in the coming months. My brother has one and he did a muffler swap, though it still isn't very loud.

I'm familiar with running straight pipes from the cat back on the many 1.8Ts I've owned, and I know you can get away with it because the turbo creates more than enough back pressure to not lose power?

So my question is, if I were to run 2.5" straight pipes from the cats back on my 4.2 S4, would I lose power? and would I be sacrificing reliability of the car? Because it's naturally aspirated?

Thanks again in advance, I know i'm a noob with this stuff so the help is appreciated lol

[jmcS4]

2.5" exhaust piping is the best size for our 4.2's. anything larger than 2.5" and you'll loose power instead of freeing it up. i would recommend a x-pipe instead of just running separate pipes like the stock setup. you may want to through a straight through muffler on the rear depending on definition of loud. the exhaust note on these cars are extremely addictive so its a matter of time before you do piggie pipes or go with FI or milltek catless dp's

maybe Jake will chime in and confirm my statement.