How To Start With Valves CLOSED: M4 CP + MPE...

[psid]

Hi all, recently bought an M4 Comp Pack with the M Performance Exhaust already fitted. Love everything about it and how it sounds, but my neighbor (that one annoying one that moans about everything) has started whinging about the noise.

I'm more of the opinion to ignore him and/or tell him to go **** himself, but if there's an easy fix/setting then I might just do it to keep the peace.

It does start up loud (awesome), as though the valves are open to begin with, and then after 1-2mins when the revs drop it quietens down. Efficient mode is always on by default when starting.

I've found lots of info on keeping exhaust valves open, but couldn't find much to do with keeping them closed - on start up that is. Seems that most people's exhaust valves are closed on startup - so maybe this is specific to the MPE?

Are they actually open on startup, or are they actually closed, and the noise is more to do with being a 'cold start'?

Any ideas?

[maul3d]

You would need to have the sequence of cold start coded out. Which would void your warranty, don't bother. Your valve closed , open, doesn't make a difference.

Enjoy it.

I do. Fuck your neighbor... IMHO. Tell him to buy some ear plugs, and eat a dick while he's at it.

[Aaaaaaaaa]

Just hope he doesn't throw a rock through your house window

[uniqueMR]

Tell your neighbor to move out
Its just cold start ritual. Values are closed within 2 seconds after start up. They won't open until in Sport or Sport+ with rpm passed 2500.

Congrats on the car. Very nice

[maul3d]

Originally Posted by BMWModel3

Just hope he doesn't throw a rock through your house window

Lol!

Link that here!!!

[Aaaaaaaaa]

Originally Posted by maul3d

Lol!

Link that here!!!

Found it
https://f80.bimmerpost.com/forums/sh....php?t=1566072

[psid]

Originally Posted by maul3d

You would need to have the sequence of cold start coded out. Which would void your warranty, don't bother. Your valve closed , open, doesn't make a difference.

Enjoy it.

I do. Fuck your neighbor... IMHO. Tell him to buy some ear plugs, and eat a dick while he's at it.

Haha, that's quite tame compared to some of things I've thought about saying to him Many thanks.

Originally Posted by uniqueMR

Tell your neighbor to move out
Its just cold start ritual. Values are closed within 2 seconds after start up. They won't open until in Sport or Sport+ with rpm passed 2500.

Congrats on the car. Very nice

Good to know, thank you

Originally Posted by BMWModel3

Found it
https://f80.bimmerpost.com/forums/sh....php?t=1566072

OMG, that actually happened... Couldn't see the video as the link/website seems to be down, but wow, what a complete c**t.

Thanks all for your help & support Problem solved.

[maul3d]

Originally Posted by BMWModel3

Found it
https://f80.bimmerpost.com/forums/sh....php?t=1566072

EPIC!

[CanAutM3]

The exhaust valves are in fact closed during the cold start warm-up sequence. They are only very briefly opened (less than a second) on the Comp pack and CS tunes for the initial "start-up roar" but then close immediately for the cold start warm-up sequence.

What causes the loud exhaust sound after start-up is in fact a combination of the turbo wastegates that are kept open and engine management parameters (valve/ignition timing) tuned to accelerate the warm-up of the catalytic converters for emissions purposes.

If you had a valve controller and were able to actually keep the exhaust valves open during start-up, you'd be startled how loud it is , particularly with an MPE.

Further, the exhaust valve control logic is no different with the MPE since there is no reprogramming of the software with MPE installation.

So no, there is no "simple" way to reduce the noise level on start-up. The only way would be getting a tune that removes the cold start sequence (this option is readily offered), but that would void your warranty.

[psid]

Originally Posted by CanAutM3

The exhaust valves are in fact closed during the cold start warm-up sequence. They are only very briefly opened (less than a second) on the Comp pack and CS tunes for the initial "start-up roar" but then close immediately for the cold start warm-up sequence.

What causes the loud exhaust sound after start-up is in fact a combination of the turbo wastegates that are kept open and engine management parameters (valve/ignition timing) tuned to accelerate the warm-up of the catalytic converters for emissions purposes.

If you had a valve controller and were able to actually keep the exhaust valves open during start-up, you'd be startled how loud it is , particularly with an MPE.

Further, the exhaust valve control logic is no different with the MPE since there is no reprogramming of the software with MPE installation.

So no, there is no "simple" way to reduce the noise level on start-up. The only way would be getting a tune that removes the cold start sequence (this option is readily offered), but that would void your warranty.

Knowledge..! Thank you.

I'm very intrigued to hear it start with valves open now though! Maybe i'll let the neighbour compare it one day, so he knows how lucky he actually is...

[ellipsis212]

Tell him you're saving the environment

[fanatic1]

Originally Posted by CanAutM3

The exhaust valves are in fact closed during the cold start warm-up sequence. They are only very briefly opened (less than a second) on the Comp pack and CS tunes for the initial "start-up roar" but then close immediately for the cold start warm-up sequence.

What causes the loud exhaust sound after start-up is in fact a combination of the turbo wastegates that are kept open and engine management parameters (valve/ignition timing) tuned to accelerate the warm-up of the catalytic converters for emissions purposes.

If you had a valve controller and were able to actually keep the exhaust valves open during start-up, you'd be startled how loud it is , particularly with an MPE.

Further, the exhaust valve control logic is no different with the MPE since there is no reprogramming of the software with MPE installation.

So no, there is no "simple" way to reduce the noise level on start-up. The only way would be getting a tune that removes the cold start sequence (this option is readily offered), but that would void your warranty.

Bought a BMS exhaust valve controller primarily for Laguna Seca 90 dB sound limit, but my neighbors appreciate it as well. It doesn’t help with the temporary increase in start up RPM though.

Debated at the track, but it sure feels like with the valves closed, throttle response is muted. Don’t have much to compare to as this was the first time on track, but did run a lap with the valves open and it certainly felt different - and blew sound.