[xDrive35i]

Anyone tried this yet? Is it possible? What about detaching the vacuum line? I'd like to know how to do this for the 35i.

[Beyu]

Lately with all this talk regarding the X3's exhaust I too am curious about the golf tee mod. I found a video showing the simplest method for doing this mod and all it requries is for you to unplug a cord in the trunk versus plugging a valve with a golf tee. I have located the cord in our X3 and have included a photo but would like to see if anyone else has done this mod and by which method you used, thanks in advance.

[xDrive35i]

Yeah I did that a few months ago. Really nice change.

[gerem]

Originally Posted by juddholland

Yeah I did that a few months ago. Really nice change.

You just unplug the cable??? Will you get any damage on your car?
Warranty problem?

Thanks in advance.

[nonagon]

Just did it...took almost no time. I think the exhaust is slightly bassier and more aggressive. Nothing too extreme though. What does this mod actually do? Is there a downside?

[Beyu]

I just did this about an hour ago but by using another method (detaching vacuum line) instead of the video I showed. Both methods do exactly the same thing but the video method doesn't require you to crawl under your car.

Originally Posted by nonagon

What does this mod actually do? Is there a downside?

Lotus wrote a very good explanation for what the mod does, man I miss his posts.

Originally Posted by Lotus7

The valve is mostly for noise control at low rpms to prevent "droning" in the car. Some people have speculated that it also is used to slightly increase the exhaust restriction to heat up the catalytic converters after start up to reduce emissions, but given the [low] exhaust flow at very low rpms that is very unlikely.

To meet exhaust sound level regulations in many countries, some aftermarket "performance" exhaust systems also use the control valve.

One performance exhaust system maker (3DDesign) says this about the valve:

What is the Control Valve?
The control valve is a simple butterfly valve that is actuated using the pressure from the vacuum lines. This valve controls the exhuast efficiency, volume and torque characteristics. Some BMW models have factory valve systems in place.

The factory computer determines the timing for the opening and shutting of the valves.
For instance (335i model):
- Always closed on neutral shift
- Opens at 2000 RPM on 1st shift position
- Opens at 4000 RPM on 2nd shift position
Opening and closing are controlled according to many different parameters
(such as the degree of throttle plate opening)

Factory vacuum lines and settings for closing and opening the valves are used for all 3DDesign exhaust systems as the design of the exhaust has been cleverly developed to allow for expansion of these settings for better performance characteristics.
Since the factory exhaust systems (where applicable) has similar valve systems, the installation is simple and no extra modifications are needed.

Plugging the vacuum line will make the car louder at low rpm and part throttle, but since the valve already opens up completely at full throttle, it won't make the car any faster.

[lbjgh]

Beyu, what side of the valve do you remove the vaccum line in the picture below.

[fiddy yen]

Just pull the connector from inside. It took me literally 10 seconds to do and completely reversable in the same amount of time.

[lbjgh]

How do you mean the 'inside'?

The vacuum actuated solenoid looks like the vacuum line doesn't come off too easily.

Originally Posted by fiddy yen

Just pull the connector from inside. It took me literally 10 seconds to do and completely reversible in the same amount of time.

[02420X3]

Leave the solenoid and the line alone. Look at post #2 in this topic.

[lbjgh]

Thanks guys... I thought that picture related to the video and I didn't know where to look.

That was a piece of cake.

Originally Posted by 02420X3

Leave the solenoid and the line alone. Look at post #2 in this topic.

[02420X3]

Enjoy!

[fiddy yen]

Originally Posted by lbjgh

How do you mean the 'inside'?

The vacuum actuated solenoid looks like the vacuum line doesn't come off too easily.

haha no problem. Glad to be a help.

[Beyu]

Just for future reference.

If you choose to do this the manual way (under the car) versus the electronic method (inside the trunk) just detach this vacuum line.

Then find something small like a screw or golf tee and plug up the hole.

[turbotoy4me]

Originally Posted by juddholland

Anyone tried this yet? Is it possible? What about detaching the vacuum line? I'd like to know how to do this for the 35i.

Originally Posted by lbjgh

Thanks guys... I thought that picture related to the video and I didn't know where to look.

That was a piece of cake.

Unplugged mine inside of my X3 a few months ago (like the example in post #11). I had my yearly service last month and they did not notice or if the service department did notice they did not say anything. Sounds slightly deeper at idle. I like the way it sounds. Good luck.

[lbjgh]

I noticed today the black crud on exhaust is now on both chrome tips.

[OneMadScientist]

Originally Posted by lbjgh

I noticed today the black crud on exhaust is now on both chrome tips.

I use a Chemical Guys metal polish on the pipes. Takes the black crud off in a jiff. Rub on and wipe off!

[02420X3]

Originally Posted by lbjgh

I noticed today the black crud on exhaust is now on both chrome tips.

You expected something different???

[Teemo Panda]

I tired this on my n20 f25, I kinda felt the car was lose, kinda jiggly on the exhaust then a bit delay on accelerating

[ReturnZero]

This is fascinating, going to have to give it a shot. Thanks for all the info everyone!

Does anyone know if the computer will throw any codes because it can't find this solenoid anymore? Looks like it won't throw a MIL, but just trying to see if there are any other downsides.

[lbjgh]

Originally Posted by 02420X3

You expected something different???

Kinda. I didn't know both tips were functional because I only ever cleaned the right tip.

[Beyu]

Originally Posted by ReturnZero

Does anyone know if the computer will throw any codes because it can't find this solenoid anymore? Looks like it won't throw a MIL, but just trying to see if there are any other downsides.

I've read on 3-series forums that if you unplug from the trunk the car will throw a minor code in the background. However, to my knowledge no one has ever gotten in trouble from the dealer nor did they mention anything to me when I got my car serviced the last two times.

If you're worried about error codes/logs you can use the method where you unplug the vacuum directly (post #14) and this won't log anything at all.

Originally Posted by lbjgh

Kinda. I didn't know both tips were functional because I only ever cleaned the right tip.

Both exhaust tips are functional but on the 35i the solenoid closes up the left side during light driving/cruising. During wide open throttle the left side opens up and both sides are used.

By doing the mod both sides are used all the time so they end up getting dirty, which isn't necessarily a bad thing since both tips now wear out evenly versus just the right side.