Originally Posted by nkgmd
The service report stated that "the noise is found coming from the rear section of the exhaust, inside of muffler during load". They replaced it, and it is better, but I can still hear a difference in the character of the exhaust note at 4000rpm. I wonder if there is something wrong with the engine that is amplified by the exhaust as well.
this was the thread I was referring to from a member in Germany, his drone was at 2000 RPM and he later found out that a fitting was loose but looks like this is not the case with your exhaust:
Problem with Performance exhaust: drone at 2.ooo rpm
my dealer in Germany installed the performance exhaust last week on my e90 M.
I really like this exhaust, it has a very exotic sound at 3.500-4000 rpm.
They only problem which I have with this exhaust is, that it drones!
My e90 has DKG and I drive it very often in the automatic mode (going to work in the morning, etc).
At 2.000 rpm the exhaust really has a drone. it is really disturbing and reduces the fun which I have with this exhaust a lot.
The automatic mode also switches gears up as fast as possible, so the engine is very often below 2.000 rpm. If you now accelerate slighty, the automatic mode will not switch the gears down. Now I get the drone
Does anyone has the same?
I am wondering, because when I checked in this forum, everyone said, that the performance exhaust has no drone at all...
Another issue which I have detected is, that the performance exhaust expanse when it is warm.
I have the hahmann-diffusor installed on my e90. With cold exhaust the tips are behind the diffusor (around 1 cm) - you can not see the ///M-logo on the tips.
If the exhaust is warm, the tips come out of the diffusor around 2-3cm - now you can see the ///M-Logo.
Has anyone recognized this on his performance exhaust?
Thank you for you helb.
Best regards from Germany,