Difference between N54 and N55 exhaust

[Crematoriant]

Since uncle Google doesn't like me and won't show me even a simple explanation...
Can anybody here tell me differences between these exhaust systems?

Many thanks

[6MT_Addict]

Originally Posted by Crematoriant

Since uncle Google doesn't like me and won't show me even a simple explanation...
Can anybody here tell me differences between these exhaust systems?

Many thanks

Use Real OEM. Biggest difference is that the N55 mid pipe has no secondary cats. N54 does.

[HyeWarrior]

N54 has two small resonators on the midpipes, and small catalytic converters on the downpipes.

N55 doesn't have the resonators on the midpipes, but has a beefy catalytic converter on the downpipe.

[Dackelone]

N55 only has ONE (larger) main cat after the one turbo - with no secondary cat on the mid pipe.

N54 has two main cats right after the turbos with two smaller (post) cats on the mid pipe.


Both N54 & N55 mid pipe have a resonator at the end of the dual pipes. Both use almost the same rear axle exhaust muffler.

Basically both exhausts are the (almost)same setup.

Btw... the 1M(N54T and Z4 35is) used the same setup as the N54, but with higher flowing main cats and higher flowing secondary cats. The part numbers are different for the DPs and mids from the normal N54 exhaust system.


N55 engine


N54 engine


N55 vs N54(top) mid pipes


N55 vs N54(right) mid pipes




N55 mid pipes with rear muffler from my N54. I installed a PE exhaust and I am SO HAPPY I did so!!


more info here...

DIY installing N55 mid pipes on a N54...
http://www.1addicts.com/forums/showthread.php?t=797160

[Dackelone]

Stock for Stock... the N55 exhaust sounds better to my ears. But put a PE on either and its an orgasmic experience for your ears!! I love my PE!!

Btw... a friend of mine has a N55 with a AR high flow cat(~$800ish) 200 cell cat on his otherwise stock car... and man does it sound good!


stock vs stock exhausts...

[SkullV]

It is my understanding that the n54 or n55 exhaust (I don't recall which one) has only one large perforation in the pipe within the muffler as opposed to the other version which has 3. While this won't change performance it will change exhaust note to some extent.

[Esteban]

Originally Posted by Dackelone

Stock for Stock... the N55 exhaust sounds better to my ears. But put a PE on either and its an orgasmic experience for your ears!! I love my PE!!

I owned both an N54 135i and now a N55 135i and I thought the same; stock for stock, the N55 sounds better. I now have the PE on my N55 and love the way it sounds and agree with Dackelone, put a PE on either one and you will be happy!

[Dackelone]

Originally Posted by SkullV

It is my understanding that the n54 or n55 exhaust (I don't recall which one) has only one large perforation in the pipe within the muffler as opposed to the other version which has 3. While this won't change performance it will change exhaust note to some extent.

Could be. But this is the first I have heard of it.

I think the reason why the N55 sounds better(stock) is bc it only has one cat as opposed to four(N54) - to muffle the exhaust sound.

Dack

[SkullV]

Originally Posted by Dackelone

Could be. But this is the first I have heard of it.

I think the reason why the N55 sounds better(stock) is bc it only has one cat as opposed to four(N54) - to muffle the exhaust sound.

Dack

I think someone asked about it in the muffler mod/wrap thread about cutting open the PE muffler.

[vtl]

The N54 and N55 mufflers are different. Here are some pics of the differences. The Y pipe inside of the muffler is perforated in the N54, N55 is solid. This Y pipe separates into 2 pipes, one is valved by the exhaust flap and the other is not.

Since the N54 is perforated at the Y pipe, the exhaust flap has little effect and does not change the exhaust note much. I did the DIY PE mod on a spare N54 muffler:

http://www.1addicts.com/forums/showp...6&postcount=18


N55:


My N54 muffler:

It is perforated on the top and bottom sides, so it makes a huge difference when you weld up all the holes. The exhaust flap now makes a big difference in volume when it is open vs closed.

[starbai]

Will N54 axleback exhausts bolt up to N55 axleback exhausts without issue?

I ask beacuse the Corsa I'm looking at seems to only be listed for years with the N54 and not the N55

[NinjaDog]

Hi all,

Looking at purchasing a BMW PE (with Y pipe) off an 2010 135i (N55) to put on my '08 135i (N54).

Will there be any issues with fitment? Should I do an N55 midpipe swap whilst I am at it? What's benefit of the Y pipe?
Also, is there any performance gain?
Cheers