Engine start with open exhaust valve in a MY18

[LukeM15]

Idk if my neighbors hate but I start mines like this.
Push start
Press M1 (set to sport)
Hold brake+push start
GTS roar+loudness

(I have the MPE) + BM3
Soon I’ll be adding the Fabspeed for an even more loud start up lol

[s0211]

Tried it on mine, 2018 w/ ZCP and it's noticeably louder.
I have audio if anyone is curious. Recorded it for someone who said didn't work for them

I will start my car like this from now on because I have shit neighbors who always leave their windows by my driveway open, so this will be fun.

[RTCalifornia]

After readying the post and testing it out myself, I found the sound when the exhaust valve are open and close noticeable.

I found that the exhaust valves open and stay open as soon as i switch to sport or sport+. Not sure if there is a difference between Model and year but mine is a 2019 M4 Conv with Competition package. The exhaust valve butterfly can be seen from the dual tail pipe. I used a flashlight to inspect the valve status.

Here are pictures as visual confirmation of when the valves are open or close.

1st picture shows closed exhaust valve. 2nd picture shows exhaust valve open. I tested from cold start to driving around for 20 minutes. Valves stay open all the time in sport and sports+.

[WIKDF80]

I just waited for the valves to open. Shut off the car. Unplugged the solenoids. No more closed valves ever.

[shay2nak]

I don't know if this has been mentioned, but with this trick of the valves opening before the car starts...do the valves stay open the entire time? Sounds like it does, but not sure. I switched to eco mode and then back to sport + and it sounded quieter than at the start. Can't fully tell because I'm still under 1200 miles and can't do WOT high RPM pulls.

[MRM2]

Originally Posted by asuh1991

That should work....

To even dumb it down more,
1)click start engine without holding brakes
2)click m2(saved as sport plus everything)
3)you should hear the valve opening
4)start car
5)super loud and obnoxious, I don't do it anymore.

Is this supposed to work on M2 Competition? Because I'm struggling for it to work on mine.. Any suggestions people?

[2015M4inCT]

Originally Posted by gatorfast

Just get a valve controller and never worry about this again.

I have the BMS can flap kit and it takes a good 2-3 seconds after the car starts before it opens up the valves. Pretty frustrating... Seems the car must automatically close the valves upon shutdown and the BMS module can't/doesn't write the code for flaps open until 2-3 seconds upon start.

[gatorfast]

Originally Posted by 2015M4inCT

I have the BMS can flap kit and it takes a good 2-3 seconds after the car starts before it opens up the valves. Pretty frustrating... Seems the car must automatically close the valves upon shutdown and the BMS module can't/doesn't write the code for flaps open until 2-3 seconds upon start.

If you want them open immediately upon starting then first turn on the ignition (dont fire up the engine), wait a few seconds, then start the car and the valves will he open.

[nbennettksu]

just unplug the valves with them open and make your neighborhood angry

[G4BR13L]

Originally Posted by gatorfast

If you want them open immediately upon starting then first turn on the ignition (dont fire up the engine), wait a few seconds, then start the car and the valves will he open.

This is only in Sport and Sport+ and there might be a difference between the European specced cars and others.

The technical training product info states the following:

Functional input variables for the calculation of the exhaust flap setting are:

• Vehicle speed
• Accelerator pedal angle
• Position of driving experience switch
• Engine temperature
• Gear mode

I have the Macht Schnell EVC and keep them closed in the morning otherwise always open and to prevent exhaust drone I keep the car in D3 or S3. This is by the way one of the reasons why the valves would close to prevent drone at certain frequencies.

[gatorfast]

Originally Posted by G4BR13L

This is only in Sport and Sport+ and there might be a difference between the European specced cars and others.

The technical training product info states the following:

Functional input variables for the calculation of the exhaust flap setting are:

• Vehicle speed
• Accelerator pedal angle
• Position of driving experience switch
• Engine temperature
• Gear mode

I have the Macht Schnell EVC and keep them closed in the morning otherwise always open and to prevent exhaust drone I keep the car in D3 or S3. This is by the way one of the reasons why the valves would close to prevent drone at certain frequencies.

The BMS can flap controller opens/closes the valves directly, regardless of which throttle setting the car is in. There is, however, a slight delay in opening the valves upon immediately starting the vehicle as the poster I quoted described. I gave him a work around which allow the valves to be fully open when he starts the engine.

[2015M4inCT]

Originally Posted by gatorfast

If you want them open immediately upon starting then first turn on the ignition (dont fire up the engine), wait a few seconds, then start the car and the valves will he open.

Cheers! This works well. I had been trying the ole turn on ignition, put into sport throttle, give it some gas but it was hit or miss most likely due to the timing of this you explained above. The cold starts with the exhaust flaps closed are embarrassingly bad...