[M2siast]

Hey all,

We were having a little debate in some other thread about whether the “flaps open” button (officially “Sound Control”) changed the exhaust note in Efficient Mode for the Engine, and how it affected other modes as well.

So I recorded this clip of a cold start to understand how it works, and what it does while idling.

What this does not test is how aggressive the exhaust is while driving (pops, bangs, and such). Maybe I’ll do that later, because this was eye opening and I want to understand if the exhaust changes while driving as well.

Engine modes:
- Efficient: pushing the button has no effect on exhaust note.
However, the sound INSIDE the car does change. So the button in efficient mode only changes the exhaust note that you hear through speakers.

- Sport: you can hear a lower tone when the flaps are open.
The sound inside the car changes to a higher volume.

- Sport Plus: you can hear a different tone, and the flaps work.
The sound inside the car has a lower tone to it.

Am I not hearing the changes in Efficient? Are they there?

Cheers

[babym_gen]

I don't hear the valve open/close in efficient so that's why the sound doesn't change. Intersting.

[M2siast]

Originally Posted by babym_gen

I don't hear the valve open/close in efficient so that's why the sound doesn't change. Intersting.

That’s right!
My CA told me it only changes the exhaust in Sport and Sport Plus, but we can definitely hear something changing inside the car, so it generated some debate and I was curious to see what happened.

I should film this while driving too to see how it actually behaves in different RPMs/load.

[c1pher]

Are you able to measure frequencies and dBs?

[M2siast]

Originally Posted by c1pher

Are you able to measure frequencies and dBs?

Are there apps for that?

[cmgbk75]

Originally Posted by M2siast

Are there apps for that?

Is that you being sarcastic now? There are apps for everything.

[c1pher]

Originally Posted by M2siast

Are there apps for that?

I know my iPhone tells me how loud the environment is.

There’s this iOS app:
https://apps.apple.com/us/app/decibe...er/id448155923

[M2siast]

Originally Posted by cmgbk75

Is that you being sarcastic now? There are apps for everything.

LOL! I guess the right question would be “which app can do what we want? Is there something reliable?”

Originally Posted by c1pher

I know my iPhone tells me how loud the environment is.

There’s this iOS app:
https://apps.apple.com/us/app/decibe...er/id448155923

I’ll give it a try!

[VIERsr]

Originally Posted by M2siast

That’s right!
My CA told me it only changes the exhaust in Sport and Sport Plus, but we can definitely hear something changing inside the car, so it generated some debate and I was curious to see what happened.

I should film this while driving too to see how it actually behaves in different RPMs/load.

Then it would be interesting to disable the ASD and see what happens when you press the exhaust button in efficient mode, evidently nothing.

[M2siast]

Originally Posted by VIERsr

Then it would be interesting to disable the ASD and see what happens when you press the exhaust button in efficient mode, evidently nothing.

It would, definitely… just don’t know how, if there’s a fuse to remove or what… there’s no coding for it that I could make work.

[Searay55555]

Originally Posted by M2siast

It would, definitely… just don’t know how, if there’s a fuse to remove or what… there’s no coding for it that I could make work.

Is ASD the piped in exhaust sound? During delivery yesterday I specifically asked about this and the genius said this car didn’t do that. He said not on the M’s. He seemed pretty knowledgeable, but I’m just not sure he is right.

[yuzu]

Originally Posted by Searay55555

Is ASD the piped in exhaust sound? During delivery yesterday I specifically asked about this and the genius said this car didn’t do that. He said not on the M’s. He seemed pretty knowledgeable, but I’m just not sure he is right.

Yeah he’s 100% wrong LOL, classic

[AZG87]

Originally Posted by yuzu

Yeah he’s 100% wrong LOL, classic

During my delivery (same dealership different CA) I was asking if there was any way to kill the piped in noise oem and they said none that they were aware of, noting he found it annoying too lol.

[Searay55555]

Maybe it can be coded out? Man I hope so. I don’t like it.

[CJ]

Thank you M2siast,
I am curious if the exhaust flaps do things at speed that they don’t do when stationary but that seems quite complex - I know people have gotten valve controllers and report hearing a difference in person but have never appreciate any difference from the videos . I don’t think they are wrong but want to experience for myself before spending more than $200 for a valve controller.

[Shadak]

Originally Posted by CJ

Thank you M2siast,
I am curious if the exhaust flaps do things at speed that they don’t do when stationary but that seems quite complex - I know people have gotten valve controllers and report hearing a difference in person but have never appreciate any difference from the videos . I don’t think they are wrong but want to experience for myself before spending more than $200 for a valve controller.

there is definitely a difference in person. If you want to test it, pull a 203 fuse when in sport+ and exhaust button on. or remove the valve actuator and open them manually.

[GregW / Oregon]

Originally Posted by AZG87

During my delivery (same dealership different CA) I was asking if there was any way to kill the piped in noise oem and they said none that they were aware of, noting he found it annoying too lol.

I read elsewhere there is a fuse you can pull - forget which one.

[GregW / Oregon]

Originally Posted by M2siast

Hey all,

We were having a little debate in some other thread about whether the “flaps open” button (officially “Sound Control”) changed the exhaust note in Efficient Mode for the Engine, and how it affected other modes as well.

Here is the technical information (for the G80/82, but sure ours is the same). So the console button definitely affects the flaps as well as the electronically produced sound.

[Autobahn SoCal]

I personally like all the options with this. I noticed cold starts on my M240 (G42) were louder (deeper) than the G87. If I need to startup in the morning it’s nice to not wake up the entire house anymore.
Also the fact that you can hit a couple buttons and make it really loud and deep is a perfect setup IMO.

[KevM2]

Yeah I agree with all those observations by the OP. One other thing I’ve noticed on my manual car, is whenever I press the clutch, I swear the exhaust sound also changes (gets deeper)… maybe the clutch also opens the valve? This is when stopped and car is at idle

[new2M2]

Originally Posted by KevM2

Yeah I agree with all those observations by the OP. One other thing I’ve noticed on my manual car, is whenever I press the clutch, I swear the exhaust sound also changes (gets deeper)… maybe the clutch also opens the valve? This is when stopped and car is at idle

I've noted this as well and was wondering the same.

[M2siast]

Originally Posted by KevM2

Yeah I agree with all those observations by the OP. One other thing I’ve noticed on my manual car, is whenever I press the clutch, I swear the exhaust sound also changes (gets deeper)… maybe the clutch also opens the valve? This is when stopped and car is at idle

When you press the clutch the engine runs more freely, so it revs a tad higher. It runs a bit more muffled with the engagement of the clutch to the gearbox.