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2Addicts | BMW 2-Series forum BMW 2 Series (F22) Forum BMW 2 Series Coupe and Cabriolet (F22/F23) General Forum Exhaust baffle on M240i

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      05-05-2019, 10:34 AM   #1
vwcrusher
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Exhaust baffle on M240i

Wondering if anyone has deactivated the baffle that closes off the left hand exhaust. I am told that it is a European inspired 'feature' to reduce noise pollution. It will only open up at higher engine revs. I am thinking that having it open all the time would improve engine breathing?

Thoughts?
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      05-05-2019, 03:07 PM   #2
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Quote:
Originally Posted by vwcrusher View Post
Wondering if anyone has deactivated the baffle that closes off the left hand exhaust. I am told that it is a European inspired 'feature' to reduce noise pollution. It will only open up at higher engine revs. I am thinking that having it open all the time would improve engine breathing?

Thoughts?
I don't think you will see any performance difference. It is a pretty simple mod to disconnect the flap actuator if you want to try. If you really want to go crazy BMS and probably others make a CAN flap controller so you can open / close it manually.
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      05-06-2019, 06:54 AM   #3
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My understanding is that flap is only closed during a cold start and opens when running in sport but I could be wrong
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      05-06-2019, 09:23 PM   #4
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If you want the flap to stay open you have to start the car and wait until the flap opens. Once the flap opens stop the engine and disconnect the flap actuator. If you disconnect it when is cold the flap will stay closed ...
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      05-07-2019, 08:04 AM   #5
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Thanks for the replies; it really doesn't seem to be a big deal, so I think I will just keep it stock...unless there is a good reason not to.

: )
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      05-08-2019, 08:51 PM   #6
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Quote:
Originally Posted by vwcrusher View Post
Thanks for the replies; it really doesn't seem to be a big deal, so I think I will just keep it stock...unless there is a good reason not to.

: )
Actually, the more I think about it the more I want a true dual exhaust. I looked at the actuator and for some reason I cannot remove the connector. I think as noted above all I need to do is go for a ride, when i get home put it in sport mode, rev the engine and the exhaust opens....only I cannot remove the connector to freeze the butterfly open.....anyone have any ideas?

thanks
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      05-13-2019, 10:51 PM   #7
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It's pretty hard to pull out. Make sure to press on the lock mechanism and pull with two hands hard.
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      05-14-2019, 03:06 PM   #8
Ron Jeffries
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you people are so lucky to have a flap ... 2018 MPE doesn't.
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      05-15-2019, 05:59 AM   #9
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Quote:
Originally Posted by POMFKIMOCHI View Post
It's pretty hard to pull out. Make sure to press on the lock mechanism and pull with two hands hard.
Thanks for the reply; actually, since my post I spoke with a reputable indy mechanic and he suggested not removing the baffle. His rationale is as follows:

- the baffle opens up as soon as there is sufficient throttle, in any mode
- the engine needs back pressure when cold

I do not know if what he suggested is accurate or not though.......
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      05-25-2019, 05:02 PM   #10
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The MPE does not have the valve. So, the engine does not 'need' it. The valve being closed on start up may increase back pressure, which may help to heat up the cat faster. Other than that, I have no clue what good, if any, it might do.
I bought the dummy flap actuator plug that comes with the MPE. I plugged that into the wire, tie wrapped the wire out of the way and covered the open electrical connector on the valve with electrical tape. Done.
Reversible, no error codes, no damage to the connectors and I have a true dual outlet muffler.
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      05-26-2019, 12:04 PM   #11
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Quote:
Originally Posted by PeterWT View Post
The MPE does not have the valve. So, the engine does not 'need' it. The valve being closed on start up may increase back pressure, which may help to heat up the cat faster. Other than that, I have no clue what good, if any, it might do.
I bought the dummy flap actuator plug that comes with the MPE. I plugged that into the wire, tie wrapped the wire out of the way and covered the open electrical connector on the valve with electrical tape. Done.
Reversible, no error codes, no damage to the connectors and I have a true dual outlet muffler.
Interesting...very. I am sorry; I am not familiar with "MPE." Would you mind sharing the source of the components you used to do this?

Thanks.
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      05-28-2019, 06:08 AM   #12
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This can be controlled with the Bimmerlink iOS App if you get a suitable OBD2 adapter. You can set it to Auto or always Open as you wish.

I recently replaced the exhaust valve fixing bow. (Mine broke and the exhaust was rattling.)

With the actuator unbolted, by activating the flap using the app, and disconnecting the actuator connector mid movement, I could line up the flap with the actuator and remount it. Otherwise the wire bow is under tension when closed, and it's impossible to position the actuator properly.

This does not require dropping the exhaust, on the M240i at least.

You could disconnect the actuator with it open, but I could not figure out how to do that while parked without Bimmerlink - which gives you almost full control over it anyway.
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      05-28-2019, 03:34 PM   #13
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Thanks for the information; I suppose the most obvious question is to whether having that baffle open all the time changed the exhaust note. Did it make it louder in general? Or just when you got on it? Or no noticeable effect at all?
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      05-29-2019, 08:28 AM   #14
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Quote:
Originally Posted by vwcrusher View Post
Thanks for the information; I suppose the most obvious question is to whether having that baffle open all the time changed the exhaust note. Did it make it louder in general? Or just when you got on it? Or no noticeable effect at all?
I'm not sure that it's much louder. You can definitely hear a difference between open and closed when you are burbling around urban streets, the note difference is quite distinct. But since it seems to open when you floor it anyway, there is no difference when it really matters so to speak.

I'm no expert on the aesthetics of of exhaust note, I am sure keener folk would appreciate the difference more.
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      05-31-2019, 02:24 PM   #15
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Quote:
Originally Posted by vwcrusher View Post
Interesting...very. I am sorry; I am not familiar with "MPE." Would you mind sharing the source of the components you used to do this?

Thanks.
MPE = M Performance Exhaust
The dummy flap actuator that comes with that muffler is available here, separately:
https://www.turnermotorsport.com/p-5...or-plug-cover/
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      06-13-2019, 10:44 AM   #16
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Thanks for the link......how much of a chore is it to deactivate and not cause alarms in the stock exhaust?
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      06-14-2019, 03:19 AM   #17
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The flap has a purpose, which is to help the engine warm up more quickly. BMW would never have put it in if it was useless, since it costs MONEY, which no auto maker wants to spend without a good reason. A cold engine also uses more fuel.
The flap opens very soon after a cold start. People notice the difference when they start the engine only because they are sitting in the stopped car or even standing outside it.
Talk about first world problems!
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      06-14-2019, 06:12 AM   #18
vwcrusher
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Quote:
Originally Posted by morphomeman View Post
The flap has a purpose, which is to help the engine warm up more quickly. BMW would never have put it in if it was useless, since it costs MONEY, which no auto maker wants to spend without a good reason. A cold engine also uses more fuel.
The flap opens very soon after a cold start. People notice the difference when they start the engine only because they are sitting in the stopped car or even standing outside it.
Talk about first world problems!
thanks for the post....I think.

LOL...read through 90% of the post on this forum and then laugh at first world problems.
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