97 s6

Considering a catback exhaust to change my exhaust note and bump performance a bit - looking for recommendations/feedback. Supersprint claims 8% power increase and not too noisy...but someone once said they were "crap". Borla's claim to fame seems to be loudness. Comments please.

jc

I have stock exhaust on my A6, but i have an APR exhaust on my TTR. There was definitely a small HP increase (keep in mind this is a turbo-charged car), but the primary difference was the exhaust note, and the fact that the car pulled more smoothly to red line.

Style12v

since backpressure makes the pistons work harder, then lowering the amount of backpressure will allow the pistons to work smoother.

So in theory yes, catback exhaust will increase performance. How much performance really depends on the engine and the system.

Each system can remove different amounts of backpressure. But on some engines there may be a bottle neck elsewhere that could prevent the full gains that might be possible.

All in all, probably not 8% max HP difference. Maybe somewhere in the RPM band, there would be a 8% gain, but not over the whole thing.

beep-beep

But I do not know, how good the catback exaust is. If you really want to deal with backpressure you need to install equals length header exaust. In this case the air will resonate in the exaust. And on the RMPS around the resonance friquency you will get a boost.

Same thing with intake - you want to increase pressure. You can put supercharger, or as case of porsche use resonance. To use it around whole range of RPM's Porsche uses "varieght length intake". It looks like the music instrument (trombone?).