[BayDriverSF]

Pretty happy with the sound of my 2021 M5C. I keep it quiet (I close the exhaust valve, and stay in Efficient Mode) in my neighborhood, but open it up once I'm outside of town.

I understand the M Performance Titanium Exhaust will be louder than the stock exhaust, and that's cool.

But the question is, how QUIET will it be at its QUIETEST? In other words if the valve is closed and I'm in Efficient Mode? In the neighborhood I still need it to be quiet.

[Jakerx]

With the M Performance Exhaust, you lose valve operation. So there is no “quiet” operation.

[Aluminati]

My 21' M5C came equipped with MPE.

Is it loud? Yes it can be very loud but that's why you get it.

At 4am when I head to the office cold start is very loud but I immediately shift it into R and go on my way. Daily driving I have the car in SPORT with sound control off.

The MPE does not have valves but the ECU will control farts, burps, bangs and pops when SPORT PLUS and sound control is turned on.

I never get any complaints and daily driving in SPORT the MPE is not loud.

[Aronis]

I drive back and forth to the hospital at all hours of the night.....it goes in Sport plus as soon as I can......I like to downshift in front of certain neighbors houses. Those with the correct yard signs, nudge nudge wink wink,

JK.

Quite is good. Hit the button to turn off the extra noise inside has effect on outside as well, just keep the revs down and you'll be pretty quiet.

Mike

[BayDriverSF]

Originally Posted by Aronis

I drive back and forth to the hospital at all hours of the night.....it goes in Sport plus as soon as I can......I like to downshift in front of certain neighbors houses. Those with the correct yard signs, nudge nudge wink wink,

JK.

Quite is good. Hit the button to turn off the extra noise inside has effect on outside as well, just keep the revs down and you'll be pretty quiet.

Mike

Originally Posted by Aronis

I drive back and forth to the hospital at all hours of the night.....it goes in Sport plus as soon as I can......I like to downshift in front of certain neighbors houses. Those with the correct yard signs, nudge nudge wink wink,

JK.

Quite is good. Hit the button to turn off the extra noise inside has effect on outside as well, just keep the revs down and you'll be pretty quiet.

Mike

Since the valve button doesn't work anymore with the performance exhaust you mean push the button for engine Efficient mode to keep it quiet? How much louder is the performance exhaust on engine Efficient mode compared to the stock exhaust?

[freshxdough]

It doesn't have valves. But it is somewhat quiet at idle. It's more of a rumble when it's just sitting and idling. Cold start can be a bit obnoxious but normal driving and idle is perfectly normal. It's when you really get into it and starting popping that it starts absolutely cracking.

[Jakerx]

If you’re considering the MPE, go with Akrapovic instead. Keeps the valves.

[Demon Barber]

Yes, it can be very quiet if you keep it out of the aggressive settings. The exception to this is cold startup, which is always very loud for about 30 seconds, unless... You just start driving off immediately, which forces the startup throttle elevation to chill. They have to do this because otherwise it would send that elevated throttle power through the torque converter, and it would "walk" instead of sit like it normally does at idle.

Here's my response from another thread about the same topic:

"The thing most folks don't get about the stock exhaust is that the button does not control the valves anyway, just burbles and pops on the overrun. That feature still works on a system with no valves, including the MPE which I have had for over 2 years now. I love it.

The valves are opened and closed by the computer based on the M settings and speed. The exhaust button is NOT an open vs closed switch for the valves. I tested this specifically before I got my MPE."

The point is, you can prove this to yourself by having your M5 idling in park with your valved OEM exhaust. Look at the valve position with a flashlight before and after pushing the exhaust button, and you'll notice they don't move. It's not an on-off "light switch" like most think.

They stay closed most of the time when in eco mode, etc, and open much more frequently and at earlier RPMs in the more aggressive M settings. The ECU controls the valves, not the button.

The button electronically controls pops and bangs on downshifting and/or letting off the accelerator, and I can confirm it has the exact same effect on a completely valveless system (my MPE for example). The button must influence ECU control of fuel injection, boost, wastegate, etc... don't know exactly what/how, but it's the way it is.

[Demon Barber]

Also, MPE tips look substantially better than akra, and you can have the system at at least 20% discount off the list price at your dealership, making it much more cost effective than the akra. Retaining the valve functionality is not meaningful.

[Jakerx]

Originally Posted by Demon Barber

Also, MPE tips look substantially better than akra.

I'll agree with you there.

Also, how does one get 20% off the MSRP?

[The5rivers]

Originally Posted by freshxdough

It doesn't have valves. But it is somewhat quiet at idle. It's more of a rumble when it's just sitting and idling. Cold start can be a bit obnoxious but normal driving and idle is perfectly normal. It's when you really get into it and starting popping that it starts absolutely cracking.

Originally Posted by Demon Barber

Yes, it can be very quiet if you keep it out of the aggressive settings. The exception to this is cold startup, which is always very loud for about 30 seconds, unless... You just start driving off immediately, which forces the startup throttle elevation to chill. They have to do this because otherwise it would send that elevated throttle power through the torque converter, and it would "walk" instead of sit like it normally does at idle.

Here's my response from another thread about the same topic:

"The thing most folks don't get about the stock exhaust is that the button does not control the valves anyway, just burbles and pops on the overrun. That feature still works on a system with no valves, including the MPE which I have had for over 2 years now. I love it.

The valves are opened and closed by the computer based on the M settings and speed. The exhaust button is NOT an open vs closed switch for the valves. I tested this specifically before I got my MPE."

The point is, you can prove this to yourself by having your M5 idling in park with your valved OEM exhaust. Look at the valve position with a flashlight before and after pushing the exhaust button, and you'll notice they don't move. It's not an on-off "light switch" like most think.

They stay closed most of the time when in eco mode, etc, and open much more frequently and at earlier RPMs in the more aggressive M settings. The ECU controls the valves, not the button.

The button electronically controls pops and bangs on downshifting and/or letting off the accelerator, and I can confirm it has the exact same effect on a completely valveless system (my MPE for example). The button must influence ECU control of fuel injection, boost, wastegate, etc... don't know exactly what/how, but it's the way it is.

Just added the MPE to my build, and this is great info, thanks! My concern was it being "loud" all the time, which I didn't want while commuting to work or longer highway drives. I didn't want to have a headache in normal commuting! But good to know that it gets louder once you really push the car and have it in the appropriate driving modes. And glad to hear that the exhaust button controls the pops and bangs, which depending on the setting may be obnoxious to some =)

[TimWM5Comp]

Hey guys does anyone know if the MPE come equipped with the resonators in it?