BMW NineT Forum banner

Electro Operated Servos For Exhaust Note Enhancement

3344 Views 8 Replies 6 Participants Last post by  street
I'm assuming this feature is controlled by the ECU and not the rider.
1 - 1 of 9 Posts
The flapper on other marques is mostly for noise control. But, every boxer is so quiet that I'm thinking it's not for noise control, but for exhaust tuning. I recall when the first GS's came out with twin cams BMW made a big deal about variable exhaust. The ideal back pressure varies with RPM and throttle. Then again, the GS is pretty loud, so maybe the flapper is just noise control.

FWIW, dealer advised me that if I go with aftermarket headers, go with ones that use the flapper. Better mid range they say.

You could try researching on one of the GS boards. They usually know what they're talking about unlike me.
1 - 1 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.