Weird exhaust noise...

[M3xican]

The car:
F80 M3
ESS Stage 1 tune
ER catless Downpipes
Akrapovic Evolution exhaust.

There is an awkward hissing noise that is being produced by the exhaust.

I know there is now going to be much more turbo noise/spool but it doesn't sound like that.

The car was checked by a very reputable shop that checked for leaks and replaced the gaskets.

The noise is still there, seems to be caused easily at 2k RMP and sometimes less like just simply tapping the gas at low speeds.

Maybe these are just noises caused by the free-flowing downpipes or titanium exhaust. OR maybe it's more than that. Any ideas on what it is or if its normal?

As always, it's tough to really capture these things on video but I've attached one below. Maybe it'll help. Notice how at 14 seconds you can hear the noise blend in with the "fart".


VIDEO
https://youtu.be/5Fi2CpZqAIQ

[M3xican]

Any ideas? I know the video doesn't help much.

[tauzins]

Originally Posted by M3xican

The car:
F80 M3
ESS Stage 1 tune
ER catless Downpipes
Akrapovic Evolution exhaust.

There is an awkward hissing noise that is being produced by the exhaust.

I know there is now going to be much more turbo noise/spool but it doesn't sound like that.

The car was checked by a very reputable shop that checked for leaks and replaced the gaskets.

The noise is still there, seems to be caused easily at 2k RMP and sometimes less like just simply tapping the gas at low speeds.

Maybe these are just noises caused by the free-flowing downpipes or titanium exhaust. OR maybe it's more than that. Any ideas on what it is or if its normal?

As always, it's tough to really capture these things on video but I've attached one below. Maybe it'll help. Notice how at 14 seconds you can hear the noise blend in with the "fart".


VIDEO
https://youtu.be/5Fi2CpZqAIQ

Did you ever figure this out?