N54 135i Exhaust Options

[Sendhur]

Hey Fanatics

I need some advice: on my N54 135i I currently have catless downpipes, I know there are also two cats in the midpipes, I was thinking of getting catless straight pipes to replace the current midpipes (i want to keep the original midpipes) and I will keep the stock back box on the car.

will this help with sound? will this help with performance? or do I have to change the back box as well?

Thanks for your assistance :thumbs:

 

[Acheron]

The N55 midpipes are catless and will fit an N54. There is some sound "gain" to be had, but ultimately the biggest change will come from changing the back box.

Watch out for excessive drone/rasping though.

 

[Sendhur]

The N55 midpipes are catless and will fit an N54. There is some sound "gain" to be had, but ultimately the biggest change will come from changing the back box.

Watch out for excessive drone/rasping though.

Thanks for your advice bud! currently there is no excessive drone in the car and I want to keep it that way! do you think its best to keep the midpipes stock and just get a bolt on performance box? what company will you suggest I can get a good performance box (dont want to import)

 

[SP33DYV]

What are you after, louder exhaust tone or better performance?
I would personally just fit the N55 midsection and maybe a BMW Performance back box. :dunno: But be prepared. These items are not cheap.

 

[UpNcOmiNg!]

^^ What he said.
I do have a performance exhaust for sale. :rollsmile:

 

[Sendhur]

What are you after, louder exhaust tone or better performance?
I would personally just fit the N55 midsection and maybe a BMW Performance back box. :dunno: But be prepared. These items are not cheap.

I want a bit of a louder exhaust tone, and if removing the cats in the midpipes gets me better performance then that will help also. thanks for your advice

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^^ What he said.
I do have a performance exhaust for sale. :rollsmile:

Thanks Devon, does that performance exhaust come with the cat less midpipes and back box?

 

[Riaan335]

I have mid cats removed, with backboxes from Powerflow. There is a bit of drone, between 1800rpm and 2400rpm, but it got better with some mileage, but not gone.

Best would be to fit resonators in place of the mid cats to get rid of the drone.

 

[UpNcOmiNg!]

Dont you wish! :rollsmile:
If i had to sell my midpipes too the price would shoot up from R8,500.00 to +-R13,500, and I'd like to keep my mids thanks very much!
So its the performance axle back system

 

[SP33DYV]

The BMW Performance exhaust only consists of the rear muffler:

The midsection is a seperate item:

And please note that it looks different from the picture.

 

[Sendhur]

I have mid cats removed, with backboxes from Powerflow. There is a bit of drone, between 1800rpm and 2400rpm, but it got better with some mileage, but not gone.

Best would be to fit resonators in place of the mid cats to get rid of the drone.

Thanks Riaan!

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Dont you wish! :rollsmile:
If i had to sell my midpipes too the price would shoot up from R8,500.00 to +-R13,500, and I'd like to keep my mids thanks very much!
So its the performance axle back system

:rollsmile: thanks bud!

---

The BMW Performance exhaust only consists of the rear muffler:

The midsection is a seperate item:

And please note that it looks different from the picture.

raise: Thanks for posting this :thumbs:

 

[SP33DYV]

BTW, the e82 can drone a lot more than the e90.
I replaced my 1M's stock mid section with that of an N55 to reduce droning.
Have a look at this post:
http://www.bmwfanatics.co.za/showthread.php?tid=31964&pid=756727#pid756727

 

[BeamerMan]

I would leave the secondary cats in, as the noise becomes a bit raspy and then add the performance box, the DP's + Performance makes it sound exotic and frankly the best sound I've ever heard.

My next mod is the performance boxes

 

[[email protected]]

akrapovic or schnitzer:thumbs:

 

[Sendhur]

Thanks for the advice guys

@zakhir that would be tops but the pricing is crazy! LOL

 

[David1]

I have catless dps and decatted mids and I love the sound, I'd reccommend you put a resonator as it drones slightly.

I had the same setup as above but with the bmw performance exhaust and it was way too loud.

 

[Nikhil]

Straight pipes ftw:fencelook: