Mpe and one sided exhaust vapor :(

drfullet87 · 03-27-2015, 01:10 PM

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I have mpe installed and that's why I am posting here. Today my boss noticed that after I started my car I was only getting any exhaust vapor or fog out of my right tailpipe. It's about 30 degrees here today so that's why it was visible. Any thoughts?

613Bimmer · 03-27-2015, 01:15 PM

The car only opens the right valve on cold start, once the engine heats up the left valve will open.

auf Deutsch · 03-27-2015, 04:41 PM

^yep totally normal......fog

drfullet87 · 03-28-2015, 09:57 PM

you guys are awesome, thank you.

horsepower_and_hounds · 03-29-2015, 06:18 AM

you can bypass that and have both sides open all the time. Just search for Flap mod

Blubaron79 · 03-29-2015, 12:25 PM

It's kind of cool if you wait for the flap to open. You can hear an electronic servo, and it opens up.

wakebord99 · 03-29-2015, 06:55 PM

I noticed the same thing. I wonder that's why the car sounds so amazing on cold starts?!

Buckeyes · 03-29-2015, 07:15 PM

Quote:

Originally Posted by wakebord99

I noticed the same thing. I wonder that's why the car sounds so amazing on cold starts?!

That not the reason. I have both sides open (golf tee) and it sound the same as one opened. It's something with the wastegate and the idle at a higher rpm to heat up the cat as fast as possible for less pollution.

obriennathaniel · 03-31-2015, 12:14 PM

theres only one flap....

Buckeyes · 03-31-2015, 12:19 PM

Quote:

Originally Posted by obriennathaniel

theres only one flap....

Ok. I meant that I have the flap always open.

tboooe · 04-01-2015, 01:12 PM

Quote:

Originally Posted by Blubaron79

It's kind of cool if you wait for the flap to open. You can hear an electronic servo, and it opens up.

I have yet to see the flap open at idle. I only know the flap open because my left side exhaust tip has some soot on it.

613Bimmer · 04-01-2015, 07:20 PM

Quote:

Originally Posted by tboooe

I have yet to see the flap open at idle. I only know the flap open because my left side exhaust tip has some soot on it.

The car also closes the flap in certain situations (I dont know which) to regulate exhaust backpressure (to do something that I'm not smart enough to understand)

RoundelM3 · 04-02-2015, 07:39 AM

Quote:

Originally Posted by Trcb777

That not the reason. I have both sides open (golf tee) and it sound the same as one opened. It's something with the wastegate and the idle at a higher rpm to heat up the cat as fast as possible for less pollution.

This is true - the wastegate stays open during cold start, allowing the exhaust to bypass the turbo (which has a muffling effect). Once it warms up (usually less than a minute), the wastegate closes and it gets quieter. I tried taping over the contacts for the servo connector, leaving the flap open, and it did give it a more aggressive note under normal driving, but with the 8AT, it had a noticeable drone at cruising throttle settings. I removed the tape and it now is loud when you're on the throttle, but quiet when you're cruising. It all depends on how much drone/noise you can tolerate.

fshubert · 04-02-2015, 06:32 PM

I pulled the spring on the current car (kept the solenoid connected) but used a wrap of baling wire to keep the flapper open. Sounds great all of the time. The cruising drone is still a lot less than the Mustang and Chargers on the road. May do the same when I pick up the new car tomorrow or just pull the plug on the solenoid and see if it throws a code. Roundel335, when you taped the contacts, did you get any dash indicators?

03-27-2015, 01:10 PM	#1
drfullet87 New Member 4 Rep 19 Posts Drives: 2014 335ix MSport MPPK MPE Join Date: Nov 2013 Location: United States iTrader: (0)	Mpe and one sided exhaust vapor :( Featured on BIMMERPOST.com I have mpe installed and that's why I am posting here. Today my boss noticed that after I started my car I was only getting any exhaust vapor or fog out of my right tailpipe. It's about 30 degrees here today so that's why it was visible. Any thoughts?
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03-27-2015, 01:15 PM	#2
613Bimmer Lieutenant 106 Rep 410 Posts Drives: One car with good steering ;) Join Date: Nov 2013 Location: Ontario, Canada iTrader: (0) Garage List 2014 435i xDrive M- ... [0.00] 2013 BMW 535i XDriv ... [0.00]	The car only opens the right valve on cold start, once the engine heats up the left valve will open.
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03-27-2015, 04:41 PM	#3
auf Deutsch Colonel 1913 Rep 2,210 Posts Drives: '17 jackrabbit on crystal meth Join Date: Dec 2013 Location: Philly burbs iTrader: (0) Garage List 2017 BMW M2 [0.00]	^yep totally normal......fog __________________ 2017 BSM M2\|6MT\|Exec\|black kidneys and gills\|full alcantara wheel\|CF spoiler\|Dinan Stage 4\|Dinan COI\|Dinan free flow exhaust with resonator delete\|Fabspeed sport cat DP\|BMS clutch stop\|465 bhp\|4.75/5 stars retired: 2014 435xi\|MPPK\|335 bhp\|3/5 stars
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03-28-2015, 09:57 PM	#4
drfullet87 New Member 4 Rep 19 Posts Drives: 2014 335ix MSport MPPK MPE Join Date: Nov 2013 Location: United States iTrader: (0)	you guys are awesome, thank you.
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03-29-2015, 06:18 AM	#5
horsepower_and_hounds Brigadier General 1836 Rep 4,203 Posts Drives: BMW Join Date: Aug 2012 Location: USA iTrader: (9)	you can bypass that and have both sides open all the time. Just search for Flap mod
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03-29-2015, 12:25 PM	#6
Blubaron79 Brigadier General 1432 Rep 4,723 Posts Drives: 2021 M340i xDrive Join Date: May 2009 Location: PA iTrader: (0)	It's kind of cool if you wait for the flap to open. You can hear an electronic servo, and it opens up. __________________ Current: 2021 M340i xDrive Previous: '18 340i xDrive; '15 335 xDrive; '14 435i xDrive; '09 335 E92 xDrive
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03-29-2015, 06:55 PM	#7
wakebord99 Private First Class 44 Rep 131 Posts Drives: 14' 328i Join Date: Oct 2014 Location: New Jersey iTrader: (0)	I noticed the same thing. I wonder that's why the car sounds so amazing on cold starts?!
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03-31-2015, 12:14 PM	#9
obriennathaniel @obriennathaniel_f30 on Instagram 515 Rep 1,063 Posts Drives: 582whp/596wtq '13 335i Join Date: Jan 2014 Location: Houston,Tx ig:obriennathaniel_f30 iTrader: (0)	theres only one flap.... __________________ CG Precision VS-1 Exhaust\DR-1 DownPipe \| PS2 Turbo\Inlet \| PDU PI w/Fuel-it platinum kit & E sensor \| GFB DV+ Diverter Valve \| BM3 w/AIC2-V\|Tune CaryTheLabelGuy \| Full E85 \| ATM FMIC \| ER Chargepipe Inlet/Outlet \| AFE Intake \| BC Coilovers \| PSS 255/40-275/35 Velos Designwerks S3 two piece 19x9/19x10 \| Osram Xenarc \| LED retro \| AWRON digital AC gauge\|
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04-02-2015, 06:32 PM	#14
fshubert Captain 89 Rep 710 Posts Drives: 2015 F30 335i Join Date: Sep 2009 Location: Northwest NJ iTrader: (0)	I pulled the spring on the current car (kept the solenoid connected) but used a wrap of baling wire to keep the flapper open. Sounds great all of the time. The cruising drone is still a lot less than the Mustang and Chargers on the road. May do the same when I pick up the new car tomorrow or just pull the plug on the solenoid and see if it throws a code. Roundel335, when you taped the contacts, did you get any dash indicators? __________________ 2018 Mustang GT \| Royal Crimson \| Black Leather \| 6-speed \| Cold Weather \| Premium Pkg \| 20" Alloy Wheels \| Tuned to 510HP \| Less than $45K Previous loves: 2015 F30 335i / 2013 F30 335i / 2009 E90 335i / 2007 E90 328xi
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