View Single Post
      12-26-2011, 04:46 PM   #4
roadsta
Private
Australia
6
Rep
52
Posts

Drives: 2012 650i
Join Date: Oct 2011
Location: Australia

iTrader: (0)

Quote:
Originally Posted by E90Fleet View Post
Its actually there to make the exhaust sound less "boomy" at low RPM
It will open at higher RPM.

Its there to make the car quieter`at low RPM
Thank you / Dankie.

This makes sense.

Also, on the cold start, I was wrong. I had a look the other day, the butterfly does not open. The exhaust probably just sounds noisier becuase of the higher engine revs at cold idle.

roadsta
Appreciate 0