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      07-03-2014, 01:44 AM   #1
kitw
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MOAR FART GUN NOISES!! (Equivalent of Golf tee mod)

The F80/F82 use electronic valves in the exhaust. You can see them in the diagram below in yellow. When you start the car, they are fully open but after warm up, they close up and gradually open at around 2500 rpm or so, depending on what mode you are in.



If you notice, the muffler is almost entirely bypassed when the valves are open. I was very surprised at how loud it is with the valves disconnected - not much difference under load, but at idle and starting off, the car is quiet a bit louder. I ended up plugging mine back in - the car doesn't sound any better. It's still flatulent, just really loudly flatulent.

Anyway, if you want to disconnect them, with the car off, lay on the ground and look up at the muffler. On the outside of each side, to the front of the car past the muffler you'll see the valves. Just squeeze the latch on top of the connector and they pull off. Secure them so they don't flop around. I found it easier to use a pair of pliers, since the latch is pretty tight.

See pics.

Unfortunately, it doesn't improve the sound at all and it just makes the car louder at part throttle and low RPM.
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      07-03-2014, 05:33 PM   #2
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Flatulence. The sound of victory!
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      07-03-2014, 08:43 PM   #3
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Quote:
Originally Posted by kitw View Post
Anyway, if you want to disconnect them, with the car off, lay on the ground and look up at the muffler. On the outside of each side, to the front of the car past the muffler you'll see the valves. Just squeeze the latch on top of the connector and they pull off. Secure them so they don't flop around. I found it easier to use a pair of pliers, since the latch is pretty tight.
Shouldn't you disconnect when car is on with flap open?
I believe flap is at closed position when car is off. Disconnecting it when off would then leave that flap permanently closed until you plug the cable back.

Anyway, does it throw any error when you leave the cable disconnected?
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      07-04-2014, 11:58 PM   #4
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Quote:
Originally Posted by parky1215 View Post
Shouldn't you disconnect when car is on with flap open?
I believe flap is at closed position when car is off. Disconnecting it when off would then leave that flap permanently closed until you plug the cable back.

Anyway, does it throw any error when you leave the cable disconnected?
All you need to do is shine a flashlight into the exhaust, and you can see. It's open when the car is off, on my car.

Honestly, it makes very little difference - in Sport or Sport Plus, the exhaust is mostly open anyway.

No CEL, but I'm sure there is an error code. Similar to unplugging the connector on an e90/e92 335i
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      08-07-2014, 09:08 AM   #5
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Thanks. Will try this when My M4 arrives. If I had DCT, I wouldn't do it and just put the car in Sport+ all the time, but with my 6MT I will loose the rev match feature in Sport+ so this is a nice solution to have both the flaps open while retaining rev matching.
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      08-07-2014, 12:39 PM   #6
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Just did this and it actually made a huge difference in start up sound, low rpm driving and parking. Now just to figure out what to do with the plugs hanging around. I suck mine through the biggest opening in the rubber exhaust hanger, but I dont like it just exposed to the elements. I wonder if wee can get a cap or something for this plug...

D
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      08-07-2014, 02:22 PM   #7
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Just wrap them up good with black electrical tape making sure to cover the contact area well.
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      08-07-2014, 04:56 PM   #8
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can someone help me and try to explain how to disconnect the wire? Does it just simply pull right out? There is a slight elevation on the top end of the coupling but I'm no certain if Im to push a tab in? It says squeeze the top connector but Im not having any luck.

Thanks guys.
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      08-07-2014, 05:42 PM   #9
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You want to grab the part of the plug that is red where the green arrows are with your fingertips. On the topside you squeeze the tab and pull away from the plug.
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      08-10-2014, 07:02 PM   #10
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I am having EAS do this for me tomorrow when i drop by to get bunch of exterior parts installed.
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      08-11-2014, 09:46 AM   #11
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Quote:
Originally Posted by Definitive View Post
You want to grab the part of the plug that is red where the green arrows are with your fingertips. On the topside you squeeze the tab and pull away from the plug.
awesome! thanks for the help. I finally got them disconnected.

The sounds isn't too bad with the valves open. There is definitely more "noise" at low rpm's. The is mod has eliminate the annoying start up rattle too.
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      08-11-2014, 09:48 AM   #12
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Quote:
Originally Posted by parky1215 View Post
I am having EAS do this for me tomorrow when i drop by to get bunch of exterior parts installed.
let us know what you think of the sound Parky1215. Can't wait to see your car after all the exterior mods.
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      08-11-2014, 10:53 AM   #13
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Quote:
Originally Posted by CatchM3 View Post
let us know what you think of the sound Parky1215. Can't wait to see your car after all the exterior mods.
Definitely. I am also removing charcoal filter from intake so that may also contribute to some sound increase.

I am heading out to eas in few minutes
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      08-14-2014, 05:43 PM   #14
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Quote:
Originally Posted by parky1215 View Post
Definitely. I am also removing charcoal filter from intake so that may also contribute to some sound increase.

I am heading out to eas in few minutes
How where the results?
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      08-14-2014, 06:33 PM   #15
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Quote:
Originally Posted by Tonymiabmw View Post
How where the results?
It sounds better as you can hear exhaust note across all rev range whether you are pressing gas pedal or not, but it produces drones at freeway cruise speed on DCT from 70-75mph (1.8-2.1k rpm).

I put the flapper cable back to exhaust.
I am going to just remove secondary cat for now and wait for some nice axle back to come out.
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      08-15-2014, 02:42 AM   #16
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Quote:
Originally Posted by parky1215
Quote:
Originally Posted by Tonymiabmw View Post
How where the results?
It sounds better as you can hear exhaust note across all rev range whether you are pressing gas pedal or not, but it produces drones at freeway cruise speed on DCT from 70-75mph (1.8-2.1k rpm).

I put the flapper cable back to exhaust.
I am going to just remove secondary cat for now and wait for some nice axle back to come out.
Just curious so you have no filter in your Intake?
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      08-15-2014, 09:59 AM   #17
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Quote:
Originally Posted by ameersM3 View Post
Just curious so you have no filter in your Intake?
I still have paper air filter in, but charcoal filter that sits on top of paper air filter is removed.
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      10-20-2014, 10:15 PM   #18
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Reviving this thread-so is it confirmed that you need to warm up the car, then go to sport mode and remove the plugs with the car on and in this mode? Or do you remove the plugs when the car has been off all night night?
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      10-20-2014, 11:30 PM   #19
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When car is off valves are open. So crawl under there and disconnect each side. Ziptie them up so they don't hang loose. Up to you if you want to cover the now open plugs on each end in some manner. I unplugged mine for some added noise and I like it. Will run this way until someone releases a reasonably priced exhaust.
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      10-21-2014, 02:54 AM   #20
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I will save 6K Euros if it works as you said. I will don't need MPE anymore Just wonder if any of you got an error signal with DCT after unplugged them?
And can u take a pic how you wrap the cable and plugs?

Thanks a lot
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      10-21-2014, 05:53 AM   #21
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Quote:
Originally Posted by rutiger View Post
When car is off valves are open. So crawl under there and disconnect each side. Ziptie them up so they don't hang loose. Up to you if you want to cover the now open plugs on each end in some manner. I unplugged mine for some added noise and I like it. Will run this way until someone releases a reasonably priced exhaust.
Since when did u unplugged them? Did you notice any problems?
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      10-23-2014, 12:25 PM   #22
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This is cool. So basically I can unplug these and have my noise AND rev-matching at the same time?
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