Aftermarket exhausts...any performance increase?

[panic]

Are aftermarket louder mufflers for M3's any good for performance as well? Has anybody ever prove with a dino sheet an increase in performance after installing one in an M3, what about in a new E92 M3?
Will the ecu 'feel' consider the variation of back pressure to variate the other parameters or eventually a tune is needed? thans/Giu

[EvoJay]

Depends on which car exactly..e46? In reality power gain from a full system with sport cats etc is minimal, let alone from just a back box. M3 engines are highly tuned from the factory and for quite alot of money you get little gains. Around 20sh bhp from exhaust and a map tweak, and Maybe 30bhp if you added cams aswell, which is quite poor to say something like evo's with forced induction.

Iv not driven an M3 in the 360-370bhp region but it should feel a fair bit more lively. Expensive tuning is the price of N/A, but there are plenty of plus points to.

[panic]

[quote=EvoJay]Depends on which car exactly..e46?

...I was talking generally, but if we want to be more specific, about the E92 M3...i'm waiting the new Eisenmann (race sound) mufflers, i just wanted to know if i'd expect a few ponies on top of the present 420 or will i get only a 'better' sound out of it.

[EvoJay]

Dont think many people could tell you if you'l see much gain on an E92 yet as they're still very new.

[taffyracer]

I always thought the best add on was a set of sports cats, retaining the OEM back box, no boom to deal with but a nice increase in performance