Exhaust

bluescoupe · 11-23-2008, 03:43 PM

My friend and I both notice that our 335i's produce carbon deposits on the passenger side exhaust tip.
Is this common?
Does anyone know why?

raleedy · 11-23-2008, 03:55 PM

That's where most of the exhaust comes out. The left pipe is largely decorative.

choopy · 11-23-2008, 03:58 PM

Wow good info. I didn't know that

javie90 · 11-23-2008, 04:01 PM

weird cuz mine is all on teh driver side.
also its not decorative. our exhausts are true duals.

Mk23 · 11-23-2008, 04:02 PM

Only after a certain RPM I believe.

stimpy · 11-23-2008, 04:03 PM

Quote:

Originally Posted by javierchoi

weird cuz mine is all on teh driver side.
also its not decorative. our exhausts are true duals.

Not exactly. The driver side exhaust only opens up at certain points. I'm not 100% sure of those points so I'll let someone else chime in.

Mk23 · 11-23-2008, 04:22 PM

I think at 3000 RPMs the driver side exhaust opens up (making it dual at that point). The reasoning behind this (from what I have read) is that when your driving very relaxed and subtle then only one exhaust is open which creates a very quite growl as opposed to a loud roar when just cruising. Anyone confirm this for me?

bsamoul · 11-23-2008, 04:26 PM

I don't think they are true dual

ac1208 · 11-23-2008, 04:32 PM

Quote:

Originally Posted by bluescoupe

My friend and I both notice that our 335i's produce carbon deposits on the passenger side exhaust tip.
Is this common?
Does anyone know why?

do the golf tee mod to get both sides to work & for improved sound!

TiAg335i · 11-23-2008, 04:47 PM

Quote:

Originally Posted by bsamoul

I don't think they are true dual

They ARE true duals...100%

There is a thing called a butterfly valve that opens and closes at certain RPM to keep down emissions.

PeteW84 · 11-23-2008, 05:12 PM

The golf tee mod will keep the valve open all the time.

javie90 · 11-23-2008, 05:32 PM

geez guys have you even seen any aftermarket exhausts?
two separate pipes all teh way to the dps. and the flap is just a valve which you can easily keep open.

bluescoupe · 11-24-2008, 09:00 PM

Thanks for the good answers! I bet most people don't know why their car has one dirty exhaust!!
Yes, I've seen under my car and believe that it is truly a dual exhaust. I didn't know about the butterfly valve opening at certain rpms.

SoCalTech · 11-24-2008, 09:23 PM

Quote:

Originally Posted by TiAg335i

They ARE true duals...100%

There is a thing called a butterfly valve that opens and closes at certain RPM to keep down emissions.

It has nothing to do with emissions. It's all about European noise laws.

Hoothout · 11-24-2008, 09:24 PM

Quote:

Originally Posted by TiAg335i

They ARE true duals...100%

There is a thing called a butterfly valve that opens and closes at certain RPM to keep down emissions.

ya its single pipe for a small amount of time in the low rpm's and then once you get past 3000rpms(atleast thats what i think it is), the second one comes into play

335e92tx · 11-24-2008, 09:47 PM

I guess yall just dont twist it enough - mine seem to be the same color.

JO3 · 11-25-2008, 12:42 AM

The driver's side exhaust is closed to help speed heating the catalytic converters during cold starts. Once they reach operating temperature, the valve opens.

MrChessy · 11-25-2008, 11:22 AM

Happens on my passenger side also. Does anyone know what to use to clean the the exhaust tip? I've tried wheel cleaners and it doesn't remove the carbon residue. Thnx...

TiAg335i · 11-25-2008, 01:24 PM

Quote:

Originally Posted by JO3

The driver's side exhaust is closed to help speed heating the catalytic converters during cold starts. Once they reach operating temperature, the valve opens.

Any validity to this statement? If so I might change it back so the valve stays closed. What would happen if the cat converters aren't heated up by leaving the valve open all the time? I would think nothing. A cat converter is just a chamber that catalyzes reactions that convert the engine emissions into safer products.

335e92tx · 11-25-2008, 03:13 PM

I was watchin as I started mine this morning - 39degrees outside and probably about 60 in the garage. Smoke out the right side for the first 60 seconds. Then (as always), the pitch of the motor changed and the left begin to putout the same amount of watervapor smoke. Very unlikely that even the precats were up to temp at that point.

Davin · 11-25-2008, 05:59 PM

Quote:

Originally Posted by choopy

Wow good info. I didn't know that

+1

Crown335xi · 11-25-2008, 09:23 PM

Quote:

Originally Posted by 335e92tx

I was watchin as I started mine this morning - 39degrees outside and probably about 60 in the garage. Smoke out the right side for the first 60 seconds. Then (as always), the pitch of the motor changed and the left begin to putout the same amount of watervapor smoke. Very unlikely that even the precats were up to temp at that point.

i was gonna post about exactly that, so i guess my car is normal good news for me =)

11-23-2008, 03:43 PM	#1
bluescoupe motorhead 57 Rep 465 Posts Drives: 2017 M2 Join Date: Mar 2008 Location: west coast, FL iTrader: (0)	Exhaust - passenger side My friend and I both notice that our 335i's produce carbon deposits on the passenger side exhaust tip. Is this common? Does anyone know why?
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11-23-2008, 03:55 PM	#2
raleedy Colonel 160 Rep 2,248 Posts Drives: 2016 228i 6-speed Join Date: Jul 2005 Location: Portland, Oregon iTrader: (0)	That's where most of the exhaust comes out. The left pipe is largely decorative.
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11-23-2008, 03:58 PM	#3
choopy Juicy Booty NomNoMnom 49 Rep 1,204 Posts Drives: 04 M3 Vert/2005 M3 Competition Join Date: Jan 2008 Location: Lemont, IL iTrader: (0)	Wow good info. I didn't know that __________________ 19" Monarch 410 Staggered \|\| Matte Black Grill \|\| 4" Exhaust Tips \|\| Dual Intake \|\| GP Tunders 7500K \|\| Money Tints \|\| JB2 \|\|Custom Start Button \|\| Updated!
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11-23-2008, 04:01 PM	#4
javie90 Private 14 Rep 91 Posts Drives: E90 335i Join Date: Mar 2007 Location: los angeles, ca iTrader: (4)	weird cuz mine is all on teh driver side. also its not decorative. our exhausts are true duals.
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11-23-2008, 04:02 PM	#5
Mk23 Major 114 Rep 1,148 Posts Drives: 09 E92 Join Date: May 2008 Location: Central Florida iTrader: (0) Garage List 2009 335i Coupe [0.00]	Only after a certain RPM I believe. __________________ 09 - 335i E92 / Monaco Blue
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11-23-2008, 04:22 PM	#7
Mk23 Major 114 Rep 1,148 Posts Drives: 09 E92 Join Date: May 2008 Location: Central Florida iTrader: (0) Garage List 2009 335i Coupe [0.00]	I think at 3000 RPMs the driver side exhaust opens up (making it dual at that point). The reasoning behind this (from what I have read) is that when your driving very relaxed and subtle then only one exhaust is open which creates a very quite growl as opposed to a loud roar when just cruising. Anyone confirm this for me? __________________ 09 - 335i E92 / Monaco Blue
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11-23-2008, 04:26 PM	#8
bsamoul Major General 165 Rep 7,433 Posts Drives: E90 325i Join Date: Feb 2007 Location: Walnut Creek, California iTrader: (2)	I don't think they are true dual __________________ -Brian 2X 2006 BMW 325i [Electric Red & Mystic Blue] \| ZPP \| V1 \| Rear Fogs \| M3 Lip Spoiler \| EAS RemoteKey \| BMS Powerbox \| Projector90 Headlights w/ LED AE \| LED plate lights \| OEM Blacklines http://www.tech-shine.com
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11-23-2008, 05:12 PM	#11
PeteW84 COBB'ed 65 Rep 2,228 Posts Drives: 13 Mini Cooper S Join Date: Apr 2008 Location: Tinley Park, IL iTrader: (1) Garage List 2008 335i [7.56]	The golf tee mod will keep the valve open all the time.
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11-23-2008, 05:32 PM	#12
javie90 Private 14 Rep 91 Posts Drives: E90 335i Join Date: Mar 2007 Location: los angeles, ca iTrader: (4)	geez guys have you even seen any aftermarket exhausts? two separate pipes all teh way to the dps. and the flap is just a valve which you can easily keep open.
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11-24-2008, 09:00 PM	#13
bluescoupe motorhead 57 Rep 465 Posts Drives: 2017 M2 Join Date: Mar 2008 Location: west coast, FL iTrader: (0)	Thanks for the good answers! I bet most people don't know why their car has one dirty exhaust!! Yes, I've seen under my car and believe that it is truly a dual exhaust. I didn't know about the butterfly valve opening at certain rpms. Last edited by bluescoupe; 11-24-2008 at 09:18 PM.. Reason: correction
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11-24-2008, 09:47 PM	#16
335e92tx ahat 1036 Rep 2,592 Posts Drives: Was '07-335e92 - Now '13-335IS Join Date: Mar 2008 Location: Texas iTrader: (6)	I guess yall just dont twist it enough - mine seem to be the same color. __________________ '13 335IS N54 (1 of 373 LeMans Blue out of 3597 total production e92)- Grey interior (1 of 24 in LMB with any trans- 1 of 14 with DCT)-MODS -MFactory LSD/MHD-BQ custom Tune/ATM-IC/AFE Momentum GT Intake/Konis/Mfront&HeimJoint Rear rods&arms/Brembos. https://photos.app.goo.gl/Lo6aHZRo7XqtPkhL8
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11-25-2008, 12:42 AM	#17
JO3 Lieutenant 12 Rep 566 Posts Drives: a lot Join Date: Mar 2006 Location: CA iTrader: (8)	The driver's side exhaust is closed to help speed heating the catalytic converters during cold starts. Once they reach operating temperature, the valve opens.
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11-25-2008, 11:22 AM	#18
MrChessy Magical Pill... 157 Rep 12,775 Posts Drives: wreckless Join Date: Nov 2008 Location: Smallville iTrader: (2)	Happens on my passenger side also. Does anyone know what to use to clean the the exhaust tip? I've tried wheel cleaners and it doesn't remove the carbon residue. Thnx...
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11-25-2008, 03:13 PM	#20
335e92tx ahat 1036 Rep 2,592 Posts Drives: Was '07-335e92 - Now '13-335IS Join Date: Mar 2008 Location: Texas iTrader: (6)	I was watchin as I started mine this morning - 39degrees outside and probably about 60 in the garage. Smoke out the right side for the first 60 seconds. Then (as always), the pitch of the motor changed and the left begin to putout the same amount of watervapor smoke. Very unlikely that even the precats were up to temp at that point. __________________ '13 335IS N54 (1 of 373 LeMans Blue out of 3597 total production e92)- Grey interior (1 of 24 in LMB with any trans- 1 of 14 with DCT)-MODS -MFactory LSD/MHD-BQ custom Tune/ATM-IC/AFE Momentum GT Intake/Konis/Mfront&HeimJoint Rear rods&arms/Brembos. https://photos.app.goo.gl/Lo6aHZRo7XqtPkhL8
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