M135i Exhaust noise

[Superlightdaa]

Been running my M135i LCI for around 5 months now and few niggles have set in. First is the exhaust noise or lack of it, anyone got any tips on improving it, after market exhaust or the like. Secondly the back end feel, I know that Birds offer a LSD, is the improvement worth the pennies?

[Huskyman]

There are a few systems you can fit, it depends if the car is in warranty or not. Have a look on realoem.com for some part numbers, BMW do a LSD and a sports exhaust system as official upgrades. Good things are reported about the birds quaife differential, but that may bugger your warranty having that fitted.

[F355GTS]

OP do you think your car is OK? mine sounds fantastic and handles like it's on rails, perhaps you should have the dealer check it over

[as7920]

BMW M Performance exhaust. Absolutely awesome and got to be one of your first mods.

Had mine on for 2 - 2 1/2 years.

Some good deals for the MPE on the BabyBMW.net forums.

[pangster79]

not got any real complaints about the stock note from my exhaust either... (you do know the note changes when in Sport/Sport+ mode don't you??)

[CSK423]

pangster79 said:

not got any real complaints about the stock note from my exhaust either... (you do know the note changes when in Sport/Sport+ mode don't you??)

What you're hearing there is the electronic box of tricks that feeds through the cars speakers, the M135i doesn't have an active exhaust.

[AdDaMan]

CSK423 said:

What you're hearing there is the electronic box of tricks that feeds through the cars speakers, the M135i doesn't have an active exhaust.

The electronic valve in the exhaust would tend to disagree with you.

[CSK423]

AdDaMan said:

The electronic valve in the exhaust would tend to disagree with you.

The valve you refer to is closed on start up from cold to generate heat within the CAT quickly, this then opens fully and stays open fully once warm.

It does not change position through comfort, sport or sport +

• edit with the exception of keeping the EU db noise rating under a certain level up to 20mph (iirc)

Edited by CSK423 on Wednesday 6th July 13:13

[335d]

CSK423 said:

What you're hearing there is the electronic box of tricks that feeds through the cars speakers, the M135i doesn't have an active exhaust.

Exactly. This post shows the 'active sound design' on the M135i, and includes videos of it switched on and off. Incidentally, I think my 335d must have the same, or virtually the same sound file, as it sounds very much like this with ASD on.

http://f20.1addicts.com/forums/showthread.php?t=78...

[rockford22]

335d said:

CSK423 said:

What you're hearing there is the electronic box of tricks that feeds through the cars speakers, the M135i doesn't have an active exhaust.

Exactly. This post shows the 'active sound design' on the M135i, and includes videos of it switched on and off. Incidentally, I think my 335d must have the same, or virtually the same sound file, as it sounds very much like this with ASD on.

http://f20.1addicts.com/forums/showthread.php?t=78...

The videos on that link are ridiculous, what a difference! I've got to be honest that it doesn't sound too different to my father's i8 either.

[bennyboysvuk]

I think the M135i's standard exhaust was designed to be completely inaudible unless being driven flat out. It seems incredibly quiet all the time with the exception of when you start it in a residential area at dawn, at which point it seems loud enough to wake the whole street.

[CarsOrBikes]

M Performance exhaust and diff are on the BMW afpt site which have discounted fitted prices, make sure you mention this to the dealer as some staff appear not to use it and quote full up in error, I think the exhaust may differ if you are likely to fit an M Performance body kit.

[335d]

rockford22 said:

The videos on that link are ridiculous, what a difference! I've got to be honest that it doesn't sound too different to my father's i8 either.

Here is one of a 320i being switched to sound like an M3 https://www.youtube.com/watch?v=EkTt5bw53ME

A few 335d owners have coded their cars to have the M3 sound (all of these sound files are already there), although I think every one of them got tired of the sound and switched back eventually.

I guess this is the shape of things to come. As engine sizes become smaller, and part electric, active sound has to fill the gap. Off to make mine sound like the Starship Enterprise...