[yoyoluking]

Dear you all:

No sure anyone in this forum face this situation before. I just try to replace my F10 535i's downpipe recently. After I went to the store and move the original one but got surprise to see the diameter is totally different from the new downpipe that I wanna to replace. It looks like OEM one got much bigger diameter than the mod one. My car is F10 LCI 535i that was build in Jan 2014 and suppose should be the same N55 engine. Just not sure why this situation happen and wondering anyone get similar situation here?

Cheers

Dave

[Sedoy]

Most likely they updated the downpipe in LCI models, the part numbers are different 18407645241 for LCI and 18327605176 for pre-LCI models.

Pre-LCI






LCI

[yoyoluking]

Originally Posted by Sedoy

Most likely they updated the downpipe in LCI models, the part numbers are different 18407645241 for LCI and 18327605176 for pre-LCI models.

Pre-LCI






LCI

If that's the case that will trigger another issue that the other end of the downpipe is connecting to turbocharger. That means the turbocharger also get bigger exhaust flange update? Then the future turbocharger upgrade will need to develop new different parts as well right?

[biz77]

Newer versions of the F10 N55 July 2013 build dates and later, use a larger 4" exhaust housing on the turbine side of the turbo vs. the older 3.5". You need a downpipe designed for the newer vehicles. This is true of all F-series BMWs.

[yoyoluking]

Originally Posted by biz77

Newer versions of the F10 N55 July 2013 build dates and later, use a larger 4" exhaust housing on the turbine side of the turbo vs. the older 3.5". You need a downpipe designed for the newer vehicles. This is true of all F-series BMWs.

Thanks for this valuable input. Also curious about downpipe's part number do changed after 2014/3/21 but the turbocharger's part number still remain the same. But obviously that turbocharger should be totally different from that date as well. Just don't understand BMW's logic behind.

Dave

[Sedoy]

Originally Posted by yoyoluking

Thanks for this valuable input. Also curious about downpipe's part number do changed after 2014/3/21 but the turbocharger's part number still remain the same. But obviously that turbocharger should be totally different from that date as well. Just don't understand BMW's logic behind.

Dave

I believe the change affected F10's from 2012/04 and on, which does show different part numbers for exhaust manifold.

[BigDeep1]

Any info and or comments how this would affect performance. Common sense would make me think bigger inlet = more air = more power. I know the exit and turbo seem to be the same; however, surely the change was made for some reason and effect.

[Aaron@Autosource]

Anyone have updates regarding other documented revisions on N55 besides the downpipe?

I had a 2012 535i and now a 2015 535i. In stock form the 15 is DEFINITELY louder than my last one. Guess this explains part of it.

[mike@x-ph.com]

A thread was posted about it a while back.
You are correct DP changed. Some aftermarket companies already have the new DP as well

[Aaron@Autosource]

Originally Posted by ssgm1x

Can someone help me understand which O2 sensors to order. I have a 2014 BMW 535i xdrive with a production date of 08/13. From my understanding BMW switched to Electronic Wastegate on 08/2013 (hence this date is relevant).
Here is the tricky part.....
Even though my car has a production date of 08/13 i do not have a Electronic wastegate. I have a Mechanical wastegate. Electronic wastegates uses a bigger diameter downpipe/turbo.
Anyway......
When i go to order new O2 sensors it says "for cars with a production date up to 08/2013". I am trying to find out the significance of this date and if i am correct about this date.....did anything else change on the motor? Will this not work on my car??

Use this link:
https://www.realoem.com/bmw/enUS/select


Input the last 7 of your VIN, and then search for the O2 sensor section and it should tell you the part # you need-