135i exhaust question

new2the3 · 01-31-2008, 10:13 AM

Does anyone know if the 135i has the exhaust valve in the muffler on one of the tips? Or is it open on both tips?

Thanks.

mikeo · 01-31-2008, 01:11 PM

The second pic in this post seems to indicate that the exhaust flap/valve operates on one of the two tips.

NOLEimit · 01-31-2008, 01:17 PM

So does anyone know the flip over point for the exhaust? I know on my R32 the valve opens above 3,400 rpms or 45mph, and then will close back up if RPMs drop below 3,000. Same type of valve we are talking about, right? Limits low speed noise, to meet European noise restrictions?

BMWeber · 01-31-2008, 01:32 PM

Quote:

Originally Posted by mikeo

The second pic in this post seems to indicate that the exhaust flap/valve operates on one of the two tips.

that's not the valve it's just a rubber dampener. the valve is on the other side. have not seen it in pictures but someone had a drawing from the ETK I think

larryn · 01-31-2008, 02:56 PM

Yes, I posted it in another thread that was similar to that one. :smile:

I think I linked to this page.

mikeo · 01-31-2008, 03:53 PM

Ah, thanks for the clarification. But doesn't the valve still only work on one of the exhaust tips?

bimmertech · 01-31-2008, 07:17 PM

yes, works on just one of the tips.

Chicago1 · 03-30-2008, 11:30 PM

So... noob question here: I've heard that if you want a more "throaty" exhaust note, there's a way to override the exhaust valve so that it stays in the open position full-time. I've seen this done on Corvettes, where you bring the RPM's up until the valve opens, and then pull the fuse, thus breaking the circuit and keeping the valve locked open. Is this something that can be done on the 135i? Any harm in doing so?

bharv2003 · 03-31-2008, 12:00 AM

Quote:

Originally Posted by Chicago1

So... noob question here: I've heard that if you want a more "throaty" exhaust note, there's a way to override the exhaust valve so that it stays in the open position full-time. I've seen this done on Corvettes, where you bring the RPM's up until the valve opens, and then pull the fuse, thus breaking the circuit and keeping the valve locked open. Is this something that can be done on the 135i? Any harm in doing so?

Yea, I'd like to know if it is possible too? And about the harm!

curtdragon · 03-31-2008, 12:13 AM

i dont see any exhaust mods on a turbo car doing harm... more flow is always better

black135 · 03-31-2008, 06:49 AM

More exhaust flow generally reduces throttle response low in the rev range but since the torque curve for the 135i is so flat and starts early this may have little impact. Only one way to find out. Interesting that many comments on the forums on exhaust flow are "damn, the flow looks restricted". I see it the other way around. The more inefficiencies (simple ones to change like exhaust systems) that BMW build in, the more opportunities for easy gains!

MZWIE · 03-31-2008, 09:22 AM

BMW's have been coming with the exhaust flap for quite some time. It is there mostly so that the cats warm up faster.

To disable it all you need to do is find the vacuum line to it pull it off and plug with something like a golf tee. Should be able to look close to the exhaust tips, if you see a little rubber hose going to it then that's it.

InsaneSkippy · 03-31-2008, 09:54 AM

Quote:

Originally Posted by e34m5

To disable it all you need to do is find the vacuum line to it pull it off and plug with something like a golf tee. Should be able to look close to the exhaust tips, if you see a little rubber hose going to it then that's it.

You also need to plug what the hose originally plugged in to. I've read that some people put a single ball bearing in the line and reconnect the line. This allows you to plug both sides and keep the attached as well.

adc · 03-31-2008, 10:41 AM

I've had the golf tee in my 335 forever and it definitely livens up things a little. But I've had to remove it in order to take my car in for the wastegate problem and it wasn't easy at all.

I'm now running a stainless steel screw in the vacuum line - #8 x 3/4" 36c from the hardware store. I think #10 would probably fit even tighter (to the point you would have to "screw" it in).

I also recommend plugging the valve metal nub with a rubber vacuum cap - you can get a bag of those at an auto store for less than $2. This is to make sure water/dirt doesn't go in, so if you ever want to restore the valve functionality you won't have any surprises.

I don't like the ball bearing idea - I'm not sure how easy it would come out after a few years. Screw will come out by using a screwdriver, in the worst case scenario.

Chicago1 · 03-31-2008, 09:33 PM

Sooo... if this is vacuum controlled, and not electronic, how do you make sure the valve is "open" before you plug the vacuum line? I guess I just don't understand how the valve works. By default (at idle, off, or low RPM) is the valve closed, and only after you hit higher RPM's does the vacuum line pull it open, thus giving you a more free-flowing exhaust, and a louder exhaust note? Just trying to make sure that it's in the "open" position before you plug the vacuum line... Anyone feel free to let me know if I'm thinking about this bass-ackwards...

MZWIE · 04-01-2008, 06:25 AM

The valve is normally open. When the car first starts it is held close via vacuum. After the car is warmed up it let's it open again.

Chicago1 · 04-01-2008, 06:21 PM

Aha. I'll try the golf-tee or machine-screw approach. Thanks for the clarification.

djmBMW · 05-15-2008, 09:40 PM

any pit-cock valve recommendations in series with vacuum hose. if so..easy on and off alternative.

01-31-2008, 10:13 AM	#1
new2the3 Colonel 380 Rep 2,067 Posts Drives: 2020 X3M Competition Join Date: Jun 2006 Location: San Diego iTrader: (0)	135i exhaust question - where is valve? Does anyone know if the 135i has the exhaust valve in the muffler on one of the tips? Or is it open on both tips? Thanks.
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01-31-2008, 01:11 PM	#2
mikeo Santa Fe Concorso 103 Rep 2,984 Posts Drives: '11 M-sport 328i, '13 X1 28i Join Date: Jul 2007 Location: Santa Fe, NM iTrader: (3)	The second pic in this post seems to indicate that the exhaust flap/valve operates on one of the two tips. __________________ Santa Fe Concorso - The Southwest's Premier Automotive Gathering.
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01-31-2008, 01:17 PM	#3
NOLEimit Private First Class 4 Rep 155 Posts Drives: Join Date: Nov 2007 iTrader: (0)	So does anyone know the flip over point for the exhaust? I know on my R32 the valve opens above 3,400 rpms or 45mph, and then will close back up if RPMs drop below 3,000. Same type of valve we are talking about, right? Limits low speed noise, to meet European noise restrictions? __________________ [SIGPIC][/SIGPIC] 135i -- Alpine White -- Coral Red -- ZSP Previous --2004 VW R32--
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01-31-2008, 02:56 PM	#5
larryn Lieutenant General 2148 Rep 10,176 Posts Drives: '97 332ti, '21 X5 45e, '16 GT4 Join Date: May 2005 Location: Seattle iTrader: (2)	Yes, I posted it in another thread that was similar to that one. :smile: I think I linked to this page.
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01-31-2008, 03:53 PM	#6
mikeo Santa Fe Concorso 103 Rep 2,984 Posts Drives: '11 M-sport 328i, '13 X1 28i Join Date: Jul 2007 Location: Santa Fe, NM iTrader: (3)	Ah, thanks for the clarification. But doesn't the valve still only work on one of the exhaust tips? __________________ Santa Fe Concorso - The Southwest's Premier Automotive Gathering.
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01-31-2008, 07:17 PM	#7
bimmertech Private First Class 4 Rep 131 Posts Drives: Join Date: Oct 2007 iTrader: (0)	yes, works on just one of the tips.
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03-30-2008, 11:30 PM	#8
Chicago1 Private First Class 5 Rep 137 Posts Drives: Join Date: Mar 2008 iTrader: (0)	So... noob question here: I've heard that if you want a more "throaty" exhaust note, there's a way to override the exhaust valve so that it stays in the open position full-time. I've seen this done on Corvettes, where you bring the RPM's up until the valve opens, and then pull the fuse, thus breaking the circuit and keeping the valve locked open. Is this something that can be done on the 135i? Any harm in doing so? __________________ SGM 135i - M-Sport - Cld Wthr - Blk 'Ette - iPod - HiFi - Grey Poplar - Riss Racing Intake - cp-e Exhaust - DINAN Stage II
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03-31-2008, 12:13 AM	#10
curtdragon Car'a'carn 473 Rep 751 Posts Drives: Audi S4 Join Date: Feb 2008 Location: Nashville iTrader: (0) Garage List 2015 Audi S4 [0.00]	i dont see any exhaust mods on a turbo car doing harm... more flow is always better
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03-31-2008, 06:49 AM	#11
black135 Private 2 Rep 98 Posts Drives: Join Date: Mar 2008 iTrader: (0)	More exhaust flow generally reduces throttle response low in the rev range but since the torque curve for the 135i is so flat and starts early this may have little impact. Only one way to find out. Interesting that many comments on the forums on exhaust flow are "damn, the flow looks restricted". I see it the other way around. The more inefficiencies (simple ones to change like exhaust systems) that BMW build in, the more opportunities for easy gains! __________________ ------------------------------------ I don't like eucalyptus trees
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03-31-2008, 09:22 AM	#12
MZWIE Lieutenant Colonel 388 Rep 1,660 Posts Drives: M2 Join Date: Jun 2007 Location: GEORGIA iTrader: (0)	BMW's have been coming with the exhaust flap for quite some time. It is there mostly so that the cats warm up faster. To disable it all you need to do is find the vacuum line to it pull it off and plug with something like a golf tee. Should be able to look close to the exhaust tips, if you see a little rubber hose going to it then that's it.
	Appreciate 0 Quote

03-31-2008, 10:41 AM	#14
adc Major General 2751 Rep 6,759 Posts Drives: 2018 F80 M3 ED Join Date: Sep 2006 Location: MD/DC iTrader: (12)	I've had the golf tee in my 335 forever and it definitely livens up things a little. But I've had to remove it in order to take my car in for the wastegate problem and it wasn't easy at all. I'm now running a stainless steel screw in the vacuum line - #8 x 3/4" 36c from the hardware store. I think #10 would probably fit even tighter (to the point you would have to "screw" it in). I also recommend plugging the valve metal nub with a rubber vacuum cap - you can get a bag of those at an auto store for less than $2. This is to make sure water/dirt doesn't go in, so if you ever want to restore the valve functionality you won't have any surprises. I don't like the ball bearing idea - I'm not sure how easy it would come out after a few years. Screw will come out by using a screwdriver, in the worst case scenario. __________________ 2018 F80 Santorini 2019 Z4 3.0i 2022 X2 M35i
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03-31-2008, 09:33 PM	#15
Chicago1 Private First Class 5 Rep 137 Posts Drives: Join Date: Mar 2008 iTrader: (0)	Sooo... if this is vacuum controlled, and not electronic, how do you make sure the valve is "open" before you plug the vacuum line? I guess I just don't understand how the valve works. By default (at idle, off, or low RPM) is the valve closed, and only after you hit higher RPM's does the vacuum line pull it open, thus giving you a more free-flowing exhaust, and a louder exhaust note? Just trying to make sure that it's in the "open" position before you plug the vacuum line... Anyone feel free to let me know if I'm thinking about this bass-ackwards... __________________ SGM 135i - M-Sport - Cld Wthr - Blk 'Ette - iPod - HiFi - Grey Poplar - Riss Racing Intake - cp-e Exhaust - DINAN Stage II
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04-01-2008, 06:25 AM	#16
MZWIE Lieutenant Colonel 388 Rep 1,660 Posts Drives: M2 Join Date: Jun 2007 Location: GEORGIA iTrader: (0)	The valve is normally open. When the car first starts it is held close via vacuum. After the car is warmed up it let's it open again.
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04-01-2008, 06:21 PM	#17
Chicago1 Private First Class 5 Rep 137 Posts Drives: Join Date: Mar 2008 iTrader: (0)	Aha. I'll try the golf-tee or machine-screw approach. Thanks for the clarification. __________________ SGM 135i - M-Sport - Cld Wthr - Blk 'Ette - iPod - HiFi - Grey Poplar - Riss Racing Intake - cp-e Exhaust - DINAN Stage II
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05-15-2008, 09:40 PM	#18
djmBMW Private 2 Rep 55 Posts Drives: 135 Join Date: Mar 2008 Location: Litchfield County, CT iTrader: (0)	any pit-cock valve recommendations in series with vacuum hose. if so..easy on and off alternative.
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