Removing MID Cats

[Zuzu]

Has anybody kept the OEM midpipes in place, and just removed the centre two mid cats and replaced with straight pipes?

[robertm]

Lost and lots of people have gotten rid of their secondary cats in one fashion or another. Most of them 135 owners since they've owned their cars awhile. Heres a link to a recent thread:

http://www.1addicts.com/forums/showthread.php?t=603367

Also recommend you venture out of this subforum. The engine and tuning section of 1 addicts is a gold mine of experience.

[Zuzu]

Originally Posted by robertm

Lost and lots of people have gotten rid of their secondary cats in one fashion or another. Most of them 135 owners since they've owned their cars awhile. Heres a link to a recent thread:

http://www.1addicts.com/forums/showthread.php?t=603367

Also recommend you venture out of this subforum. The engine and tuning section of 1 addicts is a gold mine of experience.

I know that....I have had 4441 posts since 2008 , so I know how to navigate this forum...If you havent got any practical advice, dont post.

My 135i vert had custom mid pipes for the past 3 years so I am not newbie..

I am asking 1M owners for advice who might have modded their OEM exhaust systems.

[HP Autowerks]

Originally Posted by Zuzu

Has anybody kept the OEM midpipes in place, and just removed the centre two mid cats and replaced with straight pipes?

Try to N55 mid-pipe(no secondary cats) that way you don't have to cut up your original mid-pipe.

[Zuzu]

Thanks..will try and borrow some N55 mids and give it a go.

[RaihaX]

Originally Posted by Zuzu

Thanks..will try and borrow some N55 mids and give it a go.

Does that mean the 135i midpipe is exactly the same as the 1M (under the assumption that the layout of the pipes are different on the 1M).

Was just curious!

[MusclezMarinara]

Originally Posted by RaihaX

Does that mean the 135i midpipe is exactly the same as the 1M (under the assumption that the layout of the pipes are different on the 1M).

Was just curious!

Same yes same piping think about it downpipes > to single pipe down to the axle to the new 1M Exhaust im sure guys will add it to their 135s

[Dackelone]

Some 1M guys have installed the N55 mid pipes on thier 1M in order to delete the secondary cats for a more free flowing exhuast system. For sure this would result in faster stoll up from teh turbos and better throttle response. Also probably a slightly smelly exhaust (IF that bothers you).

The 1M does have a different mid pipe (part number than that of a regular N54 135i mid pipe. So I bet the (secondary)cats are different. ?


mid pipes:

1M = 18307845669 w/secondary cats $2K plus ?
N54 = 18307559994 w/secondary cats $2,100
N55 = 18307599743 no cats - just a straight pipe and one resonator $360

1M mid pipes w/cats from RealOEM.com

[Zuzu]

Dackel, the 1M mid cats seem to be smaller in circumference than the standard N54 135i cats.

[HP Autowerks]

Originally Posted by RaihaX

Does that mean the 135i midpipe is exactly the same as the 1M (under the assumption that the layout of the pipes are different on the 1M).

Was just curious!

N54 and N55 mid pipes interchange.