BMW performance exhaust (n55)

Twinz

Forum - Support
Staff member
Congrats :thumbs:
Thanks for the review.

Put some miles on the car and the exhaust sound will "form" even more. You wont "feel" a power increase with just the bmw exhaust, but it will show on the dyno. The bmw performance mufflers free flow at least 25% more than stock. Not much but way better than stock. The real gain will obviously be in the primary decat.

The G-T mod done by unplugging the sensor is quick but it throws a soft error code. If you read your car you will see the error code....so this will be picked up by the dealer but hopefully they should not give you too much grief. The only way to get rid of the code is to plug the sensor back in and delete the code. The error free G-T mod is to unplug or "fold" the vacuum line at the bottom of the exhaust as it plugs into the exhaust.

Its up to you. I will keep the sensor unplugged as you have done...if you run the JB4 tune than you can also activate the sensor to remain open by using the steering wheel controls. :joy:
 

E82 N55 fan

New member








some photos for you guys.... I'm still trying to get some good videos to post


here is one video so long. this when i just got home and did some small revs


cold start
 

niv

New member
Very very nice!!:thumbs:

Also looking to do the rear silencer on my n54.
Deciding whether to do schnitzer or bmw performance as both are ruffly the same price.

But i must say from your video......bmw performance exhaust sounds nice!
 

E82 N55 fan

New member
thanx everybody really happy with the mod i must say.

@Bilal04 i don't have the exact prices but my exhaust was about 11k installed

the power kit is around 23k without fitment but it varies abit depending which dealer you go to:thumbs:
 

TheDonC89

Member
I prefer my stock black tips than all the after market exhaust tips. Especially on a white 135i. Does the n55 midpipe bolt straight onto n54 midpipe? I wanna delete my cats without getting MP voided and from what i heard the n55 midpipe came catless?. I don't mind taking stuff on and off as I have a friend with a mechanic workshop and i'm in it frequently (not because of car problems). If anyone can assist that would be great. Oh and the pricing and if it's not better to make custom one as it is more likely to be cheaper, but i want everthing to bolt on no cut and weld stories. Would deleting them throw a code or is that just the DP ones?
 

Twinz

Forum - Support
Staff member
For your N55 you will have to remove the catted downpipes for catless downpipes. This is a straight bolt-on exercise. No need to cut or bolt anything. Thats about it. Like you say your mechanic can install or uninstall it for you. Its not something that you can do yourself without raising the car and put in some manual labour.

But you not going to enjoy the benefits of the decat without a tune. And your car will throw limp codes after the decat but this can be easily sorted. You can drop me a PM if interested. :thumbs:
 

TheDonC89

Member
BMW rate my car has a tune from previous owner as I only recently got the vehicle and 2 weeks in the boost pipe went soft and limp mode, also got AFE intake stage 2 with DAS, I just wanna eliminate the cats on the mid pipe. I have a n54.

Will eliminating the mid pipe cats throw a code? I didn't get a good look but didn't see any sensors of any sort

I just want to bolt on and off I don't wanna cut the cats out because BMW will prob give me grief as I am on MP?

Don't wanna touch dp yet as I wanna investigate more as to whether BMW have a way to detect that? I know it apparently throws a code with the dp cats because of the landa sensors
 

Twinz

Forum - Support
Staff member
TheDon...Your 135 does not have midpipes...only catted Downpipe.

BMW will give you grief for all the mods currently on your car.
 

TheDonC89

Member
When I looked under the car from the dp bolts to back box there are more bolts between back box and dp there are 2 monster looking cats then a box. Is this not the mid pipe otherwise I am lost.
 

UpNcOmiNg!

Events Organiser
You have the N54, am I corrrect?
The N55 doesnt have the 2 mid-cats, so yes, you could change the midpipe and thus do the mid-pipe cat delete
 

TheDonC89

Member
BMW won't know if taken off? And I can't even put sw on car stock cos they rate previous owner got sw done and they said they will just be quiet about it. Any suggestions? I can ask BMW to put stock on and read and take that file, my friend does sw here an he already has my file which we thought was stock but evidently not. So I can just alternate between files? But BMW said they couldn't pick up the file but could feel it was strong.

Thanks upncoming, I was informed of this from an 1M fanatic in JHB who had a 135i before, no one knows the price? Would custom be better and cheaper?
 

Twinz

Forum - Support
Staff member
TheDon

1. Your 135 N54 car has got no Midpipes/Mid-cats...so its deleted from the factory.
 
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