Stock 650 Exhaust & M6 Exhaust Exits

[Chili Palmer]

I'm going to pick up a 650 GC and want to change the stock mufflers to M6 mufflers to get a little bit more rumble. I came from an F10 550 and the M5 muffler outlets were slightly more inboard than the openings in stock diffuser, thus requiring changing the diffuser to an M5 variation. Is this true also on the 650 GC or can I keep the stock diffuser?

[BMPOWERED]

I also changed my 650i mufflers to M6 mufflers. In my case, I changed to an aftermarket M6 style diffuser before changing the mufflers. The stock trapezoid mufflers did indeed fit within the M6 style diffuser. When I switched to M6 mufflers, they sat in the same location as the trapezoids. However, you may have an issue with the M6 muffler tips fitting within the stock opening since the dual 3" tips are rather spaced out.

[Chili Palmer]

Thanks, that's the answer I was looking for - I don't have to do both at the same time (but I probably will). Is there any trimming of the inner bumper pad under the diffuser necessary like on the 5 series?

[BMPOWERED]

Originally Posted by Chili Palmer

Thanks, that's the answer I was looking for - I don't have to do both at the same time (but I probably will). Is there any trimming of the inner bumper pad under the diffuser necessary like on the 5 series?

Not sure but I don't believe any trimming was necessary in my case. One thing of note though, the hangers on the M6 mufflers may have to be relocated, but its pretty easy for any decent muffler shop. BTW good luck with the 650...I also came from an F10 550i and I have been very happy with the 6er