Exhaust trick?

[cpandrewschmidt]

Anyone ever tried this little trick that the M2's do on our 135i's with DCT to see if the exhaust burbles get louder? Would love the cold start sound to be there all the time.

http://f87.bimmerpost.com/forums/sho...1277527&page=2

"Perhaps this is the same result as what we were told on our M Tour #2. That if you first press the ignition, but not crank over the engine, then put it in Sports+ mode, then fire up the engine, you we get the "loud" mode at startup.

We were also informed that there is a method to keep the exhaust flap permanently open. With the engine at regular operating temp, put the car in Sports+, then go underneath the car and pull the electrical connector to the exhaust valve which controls the flap. This will lock the flap in the open position."

Been driving my e30 vert with summer weather so haven't had a chance to test it out. I will next time I get it out. Just curious if we have some hidden coding in there.

Andrew

[Yeineken]

I don't think so? Considering the software is a lot different from the M2 to our 135i.

I'll have to test it out in few mins when I leave for work and I will report back.

[Dackelone]

135i's have a vacuum operated exhaust servo(hence the golf T mod). M2/M4's have an electrical servo.

[Fume]

Originally Posted by cpandrewschmidt

...
We were also informed that there is a method to keep the exhaust flap permanently open. With the engine at regular operating temp, put the car in Sports+, then go underneath the car and pull the electrical connector to the exhaust valve which controls the flap. This will lock the flap in the open position."

This description of disabling the exhaust flap to keep it open just sounds like the golf T mod that people have been doing on 1ers.

[1DrivingEmbalmer]

Originally Posted by cpandrewschmidt

Anyone ever tried this little trick that the M2's do on our 135i's with DCT to see if the exhaust burbles get louder? Would love the cold start sound to be there all the time.

http://f87.bimmerpost.com/forums/sho...1277527&page=2

"Perhaps this is the same result as what we were told on our M Tour #2. That if you first press the ignition, but not crank over the engine, then put it in Sports+ mode, then fire up the engine, you we get the "loud" mode at startup.

We were also informed that there is a method to keep the exhaust flap permanently open. With the engine at regular operating temp, put the car in Sports+, then go underneath the car and pull the electrical connector to the exhaust valve which controls the flap. This will lock the flap in the open position."

Been driving my e30 vert with summer weather so haven't had a chance to test it out. I will next time I get it out. Just curious if we have some hidden coding in there.

Andrew

I too wondered after reading the M2 post and decided to play with the settings yesterday, I noticed no difference. I have a Dinan exhaust on my vehicle.

[ShocknAwe]

Originally Posted by 1DrivingEmbalmer

I too wondered after reading the M2 post and decided to play with the settings yesterday, I noticed no difference. I have a Dinan exhaust on my vehicle.

That's because the exhaust valve is vacuum actuated. Three ways to make the exhaust louder on 135i 1ers:

1. Golf Tee Mod

2. Aftermarket exhaust parts

3. Force the wastegates full open when below like 5% throttle (JB4/MHD).

Edit: saw you have the Dinan unit, which unless I'm mistaken doesn't even have a flapper.

[Dat Aus]

What is the golf tee mod?

[Dackelone]

Originally Posted by Dat Aus

What is the golf tee mod?

You basically disconnect the vacuum line that goes to the exhaust flapper valve and stuff a golf tee into the hose end.

Golf Tee Mod...
http://www.1addicts.com/forums/showthread.php?t=213042

http://www.1addicts.com/forums/showthread.php?t=594188

http://www.1addicts.com/forums/showthread.php?t=214066

Negative effects of Golf Tee Mod?
http://www.1addicts.com/forums/showthread.php?t=415845



Personally, IF you want a louder exhaust the BEST thing you can do is to get a PE for the 135i. I messed around with installing N55 mids only to go back to stock and installed a PE. I should have just done that. The PE is the BEST sounding awesomeness exhaust I have had on any car. It really makes the car so much nicer to drive. I LOVE it!

Here is what the OE vx PE exhaust looks like. The PE has chrome tips(vs the OE's black tips) and the PE does not have this vacuum operated servo.

[mr.fabulous]

PE is just cat-back?

[mackeroni]

Originally Posted by Dackelone

...and the PE does not have this vacuum operated servo.
Attachment 1451329

...

Why is the vacuum operated servo required with the standard muffler, but not with the PE?

[mtowle182]

Originally Posted by mr.fabulous

PE is just cat-back?

it also comes with a y-pipe that removes the two resonators

[Esteban]

Originally Posted by mackeroni

Why is the vacuum operated servo required with the standard muffler, but not with the PE?

The PE does not have have a flap in one of the exhausts that opens and closes and makes the exhaust sound louder (flap open) and quieter (flap closed) like the standard muffler. Both of the exhausts in the PE are always open and you get maximum volume all the time.

[mackeroni]

Originally Posted by Esteban

The PE does not have have a flap in one of the exhausts that opens and closes and makes the exhaust sound louder (flap open) and quieter (flap closed) like the standard muffler. Both of the exhausts in the PE are always open and you get maximum volume all the time.

Yes, I understand that. My question is Why? Why does the standard exhaust NEED to have the flapper valve? Why is it there if it is totally unnecessary?

[Esteban]

Originally Posted by mackeroni

Yes, I understand that. My question is Why? Why does the standard exhaust NEED to have the flapper valve? Why is it there if it is totally unnecessary?

Good question. My guess would be to keep it quieter at times, and then be able to open her up and really hear it when you step on it? Personally, I want to hear it most of the time.

[mackeroni]

Originally Posted by Esteban

Good question. My guess would be to keep it quieter at times, and then be able to open her up and really hear it when you step on it? Personally, I want to hear it most of the time.

Thanks Esteban... So that's it? All that cost and complexity to simply keep it a tiny little bit quieter at start up?

I have read through the all the posts that Dackelone referenced above, and I found some additional conflicting information that you might be able to clear up for me. The very common opinion seems to be that the golf tee mod keeps both outlets open ABOVE 3,000 RPM for improved sound. However, there is a link to a YouTube video that shows that the flapper opens up immediately after the engine warms up. The guy in the video is holding a piece of cardboard up against the outlets one at a time. Both are clearly open at warm idle. This begs the question...Why do the mod if both are open from the point the car warms up anyway?

Thanks for helping me understand.

[Dackelone]

Originally Posted by mackeroni

Why is the vacuum operated servo required with the standard muffler, but not with the PE?

Because BMW knows the person who spends the money on a PE wants a loud exhaust ALL the time.

On the PE there is a place/fitting where the car's vacuum line slides onto - so there is no (vacuum)leak.


The reason why BMW(and others) use a flapper valve is there are some very tough noise standards in Switzerland(and other countries). I've actually seen Blitzers(Photo radar) in Switzerland that will blitz you for your exhaust being too loud! lol

[Esteban]

Dackelone thanks for clearing that up for us!

[mackeroni]

Ok. I am finally sold. I will try this mod very soon. Thanks guys!

[mr.fabulous]

Originally Posted by mackeroni

Ok. I am finally sold. I will try this mod very soon. Thanks guys!

instead disconnect the electrics at the actuator (behind the trunk liner along the side at the left), no need to get that suit dirty

[mr.fabulous]

I have a somewhat related question. My flap is non-operational, the electrics are disconnected at the actuator (solenoid that opens/closes the vacuum line to the flap) . But when I start the car up cold,, I clearly have a more throaty exhaust note at idle for the first 15-20 seconds... and then it quiets down a bit. Is there some cold-start emissions thing causing this?

[mackeroni]

Originally Posted by mr.fabulous

I have a somewhat related question. My flap is non-operational, the electrics are disconnected at the actuator (solenoid that opens/closes the vacuum line to the flap) . But when I start the car up cold,, I clearly have a more throaty exhaust note at idle for the first 15-20 seconds... and then it quiets down a bit. Is there some cold-start emissions thing causing this?

I say automatic choke is making it run richer at start up.

[Esteban]

Originally Posted by mr.fabulous

I have a somewhat related question. My flap is non-operational, the electrics are disconnected at the actuator (solenoid that opens/closes the vacuum line to the flap) . But when I start the car up cold,, I clearly have a more throaty exhaust note at idle for the first 15-20 seconds... and then it quiets down a bit. Is there some cold-start emissions thing causing this?

I think I read somewhere that one the reasons for cold start-up is to bring the catalytic converters up to temperature to reduce emissions. Personally, I like the loud cold start-up.