DIY: 335i Exhaust Sound Mod. Better, and even easier than golf tee mod.

DIY: 335i Exhaust Sound Mod. Better, and even easier than golf tee mod.
Revlis
08-28-2007

OK I know I am not the first to do this, someone had to clue me in, but instead of plugging, crimping, or otherwise disconnecting the vacuum line under the car, just unplug the actuator in the trunk in front of the drivers side tail light. I was a little unclear as to how this works, but it's dead...

Click here to read the entire tutorial

#154

By dailo on 06-29-2008, 10:09 PM

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When I did it on my 08 E92 335i I noticed it right away. Might be because I did it in my garage and just wow the roar was so much louder. Almost scared me a bit. I haven't had the chance to drive around with it yet, but the startup sound alone is well worth it for me. Not sure if it effects MPG, but from the sound you think it would.

Quote:

Originally Posted by xPaulBaiLeyx

Wrong. I just did it to my 2006 330i.
It has it too.
not sure i really noticed any difference at all though. . .
Seemed like nothing changed.
Does it take a while to kick in or should i notice it right away?

#155

By PaulBailey@ltbmw on 06-30-2008, 12:48 AM

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^
Hmm. . . could definitely be more noticable on the 335i because of the dual exhaust. . .
maybe that's why i don't notice

#156

By WERND on 07-04-2008, 09:12 PM

Very nice thing to do. Love the sound it gives

#157

By darkphantom on 07-05-2008, 12:39 AM

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it's noticeable on the 335i's because the valve is closed on startup and suppressed under 2500 RPM, but after that it opens up. I don't think the 330i's have that type of system since they only have one muffler....correct me if i'm wrong.

#158

By marlie on 07-16-2008, 04:35 AM

excellent quick mod!!! sounds awesome on start up.. gonna take it for a spin when i finish work cant wait!!

#159

By dailo on 07-16-2008, 11:41 AM

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Saw this from another thread in the Turbo forum....

Quote:

Originally Posted by bimmerpath

To those seeking to modify the flap in the exhaust - a warning. I had unplugged the wire harness behind the tail light panel to keep the flap open at all times. I performed this mod nearly a year ago. I had recently noticed a pulsing of the throttle at constant speed. The pulsing was getting progressively worse, to the point that I thought I was going to stall at some points. I took the car in, they ran all computer tests, couldn't find any faults, except for my disconnected harness mod. They didn't think that was a problem. They were stumped and began working with BMW engineers to find out what was causing the pulsing throttle. The cause- the disconnected harness was causing the computer to constantly calculate the correct parameters to compensate for the minor back pressure drops caused by the flap not closing (the flap should be closed at constant speed).

After all that, they loaded the new 30.0 software and cleared all adaptations.

As to the lag people are experiencing, it is my opinion that the drive-by-wire throttle adapts to peoples' driving habits and initially the throttle is not sure if you want full on gas, so it hesitates and then gives you the gas. Drive your car hard for a while and I think people will notice the responsiveness comes back - it has for me.

To all those who think the new software causes turbo lag, it would be nice if an engineer would chime in with their opinion. It would seem to me that turbo lag would be entirely mechanical and could not be effected by a software mod.

#160

By spec 123 on 07-17-2008, 02:36 PM

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be careful!!!

dOING IT FOR A SHORT PERIOD OF TIME MIGHT BE OKAY BUT LONGER THAN A WEEK OR FREEWAY DRIVING WILL CAUSE DAMAGE TO YOUR CATALYTIC CONVERTORS. BMW ADDED THIS DUE TO THE NOISE REDUCTION BUT ALSO THE DUAL PIPES ON THE 335 TAKE TURNS RELEASING EXHAUST FUMES. tHE AIR FUEL MIXTURE MIGHT GO LEAN OR RICH AND CAUSE YOUR CATS TO BURN. TRUST ME I KNOW

#161

By KanosWRX on 07-17-2008, 04:09 PM

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Quote:

Originally Posted by spec 123

How do you know I might ask? The car is going to release the same amount of pollution no matter which muffler/s is active or not. The cats are pre mufflers so the gas goes by them before it even touches the mufflers. I don't see how it could have any effect on the cats.

#162

By darkphantom on 07-19-2008, 05:12 PM

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need proof...I call BS!

#163

By spec 123 on 07-22-2008, 10:49 AM

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PROOF

If U Need Proof, Well Just Keep It Unpluged... Eventually U Will See Glittery Like Substance On Ur Bumper. Thats Ur Cats Melting Coming Out Of Ur Exhaust

#164

By darkphantom on 07-22-2008, 02:37 PM

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Quote:

Originally Posted by spec 123

If U Need Proof, Well Just Keep It Unpluged... Eventually U Will See Glittery Like Substance On Ur Bumper. Thats Ur Cats Melting Coming Out Of Ur Exhaust

dude, the E92s have been out since late 2006 - why is this the first time i'm hearing about this since there are so many members on here with the same mod, and also, why hasn't anyone else brought this up?

#165

By spec 123 on 07-25-2008, 12:48 AM

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just a warning

its just a warning to new members who should think twice. It has to do with the vavles opening/closing. unplugging something isnt always a good thing to do for the LONGRUN! once in a while short periods of time okay. Im not saying don't do it. just take into account that there could be some problems with the ecu readings. Not everyone on this forum wants to unplug something in their car.

#166

By dreamk on 07-25-2008, 09:28 AM

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the golf tee is easy . this will log a error. the golf tee will not

#167

By booyah on 08-23-2008, 07:56 PM

I just got my new 08 335xi and I notice on startup it closes but after a few minutes it opens up, does it stay open after that? I always go to check the pipe flap after we arrive at wherever and it always seems to be open?? Is this just a warmup flap?

#168

By Turkishexpress on 08-25-2008, 09:15 PM

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Quote:

Originally Posted by spec 123

If U Need Proof, Well Just Keep It Unpluged... Eventually U Will See Glittery Like Substance On Ur Bumper. Thats Ur Cats Melting Coming Out Of Ur Exhaust

Thats technically a good thing. Its kind of like putting leaded gas to kill the cats hence ending up with gutted cats that result in increased performance!

#169

By myulrchi on 08-30-2008, 09:36 AM

I seriously doubt that increasing the backpressure by sucha miniscule amount durning low rpm is going to cause a cat to die any quicker than normal wear and tear. One flap at the end of whole exhaust system is not going to make your backpressure change significantly. If you want to talk about back pressure making a difference remove your cat and run a strait pipe. You will lose some back pressure but your turbo will spool much quicker.
The only negative thing i've have read through this thread is possibly what Dailo posted about the computer constantly recalulation for the back pressure loss. Then again i dont know why it didnt just adapt to it. What if your driving wot all the time? It should stay open. lol.

#170

By skitlz on 09-01-2008, 02:58 PM

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hey everyone, finally got around to registering, and this is the first post.. been browsing these forums for a long time. anyways though, picked up my e92 335i on Thursday, racked up a quick 900 miles during the weekend(so close for the break in to be finished)

and finally decided to try doing this mod. i think i read pretty much all the different posts.. about 10 of them covering different ways of doing this ect.. golf tee, BB, ziptie, this unplugging method..

i opened up the grey box on the left hand side, saw the solenoid plug... really easy to unplug on the 08's btw.. not as crammed as your pics..

but ya, decided on just doing the ziptie method i read on one of the other topics to avoid the error codes.. took less then a minute.. but was just curious if anyone knew with the hose plugged/(disconected/folded over and ziptied) is going to cause the solenoid in the trunk to overheat or something? since it is still trying to open and close the baffle in the exaust..

dont want to be burning something up in the trunk, since that would be bad, heh..

any inputs would be greatly appreciated..

and btw.. didnt notice much of a difference at startup, but the low rpms does sound alot meaner, with a lil more turbo whistle which i love. and maybe im crazy, but it does seem to hesitate a lil on the low end now. but a small sacrifice for me.. since it still hauls a*

#171

By darkphantom on 09-01-2008, 11:42 PM

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^ you don't have to worry about anything by unhooking the actuator plug in the back, like mentioned above, it's a vacuum hose for the exhaust flap.

#172

By Montego335ci on 09-02-2008, 09:14 AM

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So does this mod make any differnce with aftermarket exhaust or is this just for stock exhaust?

#173

By AJerman on 09-02-2008, 09:51 AM

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Quote:

Originally Posted by Montego335ci

So does this mod make any differnce with aftermarket exhaust or is this just for stock exhaust?

Just stock. Aftermarket wouldn't have the flap.

#174

By booyah on 09-06-2008, 06:52 PM

I just took the rubber vaccum hose off at the tail-pipe, all is well and sounds great. Much more tone now from just normal driving around I noticed

#175

By J604 on 09-09-2008, 11:39 PM

did this today, can for sure notice a difference.

I think il plug it back in befor I go into the dealer for any work though, just to be safe

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