[leeadam]

Ive read so many posts on disconnecting the exhaust valve once car is warmed up and valve open. BUT....heres my question. If i look up rear pipe i see valve shut on cold start up, but once mine is warm, i pull over and check again while engine still running and it makes no difference if its in Sport or Comfort, the valve remains open? Ive heard others saying only in Sport the valve opens, but seems to not be the case.

So what is point of disconnecting it, if its always open once warm anyway?
I hope that all makes sense?

Id love it to sound more like it does in sport mode while in comfort mode too.

[XutvJet]

Once the engine is at a certain operating temp, the valve is open in Comfort, Sport, Sport+, and DSC Off. In Sport and Sport+, the maximum amount of exhaust overrun (the popping sound) is incorporated and in DSC Off, a more limited amount of overrun is used. In Comfort, there is no overrun effect though the muffler design allows for some minor natural popping effect. The overrun feature is simply the ECU injecting a slight amount of fuel on the exhaust stroke.

If you want a Comfort suspension and steering while having the noise, simply go into the Sport configure mode and select "Drivetrain". That gives you the Sport sound and more aggressive throttle mapping but Comfort suspension and steering.

[leeadam]

ok, so basically the exhaust valve disconnect really does nothing in terms of sound as it stays open in sport or comfort mode when warm anyway. I was unsure why people doing it

[leeadam]

Ive hear what you say about altering configeration in sport but i tend to drive most of time in comfort to save fuel and less agressive changes, but be nice to still have the sound of sport rasp. so thats not really an option. My question is more related to why people stick the valve open in exhaust as its open all the time in both modes anyway.? does that make sense?

[pz619]

It's not actually open all the time. There are times in sport mode where it closes as well. Seems to be largely RPM dependent. Next time you drive behind a BMW take a look at the exhaust pipe. Especially in stop and go traffic you'll see the valve open and close.

[leeadam]

Originally Posted by pz619

It's not actually open all the time. There are times in sport mode where it closes as well. Seems to be largely RPM dependent. Next time you drive behind a BMW take a look at the exhaust pipe. Especially in stop and go traffic you'll see the valve open and close.

Oh ok thats interesting so your basically saying it alters dependant on driving conditions, So have people noticed better sound with it disconnect...anyone here able to comment on that.

[pz619]

Originally Posted by leeadam

Oh ok thats interesting so your basically saying it alters dependant on driving conditions, So have people noticed better sound with it disconnect...anyone here able to comment on that.

I did the disconnect and honestly the change is minor. Maybe slightly more sound coming from a dead stop or low rpms.

[leeadam]

ah ok, yeah i guess it cant make too much difference but interesting to know. thanks