AC Schnitzer Exhaust - Annoyingly Booming - Usual ?

[redgriff500]

I have just bought a SC'd 330 and as part of the SC package from BMW it comes with the Schnitzer exhaust - the noise is totally unacceptable, with an annoying resonating boom in the car and what I'd expect if I paid £50 for an Ebay special.

So is there a problem (its 4 years old) or are they just like that ?

Its so bad I'm thinking of sticking a std one on it.

[smartie]

we had one on an E46 M3 and found it quite boomy too! Certianly wouldn't buy one, though managed to live with it as it was on car when bought.

[Dunk76]

Check it's got the resonance restrictor valve fitted - look up the right hand of the two tail pipe with the engine off - you should see a flap closed about 6-8" in (i.e. you can't see into the exhaust)

For comparison your 2-8 would have had one, as would a stock 330 system.

The one on the Alpina wasn't working when I got it, and the resonance was appalling - even on light load at say 70mph.

[redgriff500]

Resonating - thats what I meant.

Just looked, there is no valve / flap you can see straight through the box on both tailpipes.

I guess I'll try one of those decibel inserts you see being sold for track day use.

I expected better from a supposed quality manufacturer.