125/128i with 135i axle back with genuine BMW Y-Pipe HELP!

George125ie82 · 05-27-2014, 06:18 AM

Hi guys need some help.

I have an AUS e82 125i, Recently just bought a 135i axle back stock exhaust and a genuine BMW Y-Pipe to fit onto my stock 125i mids. After having taken it to the exhaust shop today I figured that they were not a direct bolt on as I had presumed. The angle of the Y-pipe is obviously different to my mids in both angle and diameter (5mm?), I'm presuming this was because the Y-Pipe was made to fit the 135i PE and N55 mids. It looks like a custom flange or adapter will need to be made to bring the two together.

Also I have an opportunity to buy N55 mids which will obviously ease the pain of making any custom joints but have read up on some other posts that they will need adjusting in order to connect to the headers?

If anyone has done this set up or something similar could you please explain the process you had to go through in order to make them fit. If you have pictures that would be even better.

Thanks for your time

andrey_gta · 07-12-2014, 12:00 AM

Yes n55 mids need adjusting too.

I have seen some one in Germany make Y pipe and n55 mids work. They cut the ends of the n55 off and welded 125i diameter pipe with flange.
This worked but i think it is crude.

Locally i have heard of a Toronto 128i making n55 mids work without adjusting them.
I think he did one of the following:
A) cut the 125i header/exhaust manifold and make fit to n55 mids.
B) create connector between 125i header and n55 mids - it would need to be up to 3 cm and would essentially work like this.
one side had flange made for 125i header, the other is a flange made for 135i n55 mid pipes. This might be a little tight but i think it can work. The adapter needs to meet 125i header as male or female, the 135i side as the opposite. Gaskets of each car on both sides. The bolts of 125i header need to be Bent outward most likely to match n55 mids

128i/125i gasket - http://www.ecstuning.com/ES39474/
http://parts.bmwofsouthatlanta.com/p...107549447.html

135i gasket -http://www.ecstuning.com/ES40634/
http://parts.bmwofsouthatlanta.com/p...307553603.html

Idea is like this - Part # 18111712064
or this -

05-27-2014, 06:18 AM	#1
George125ie82 New Member 0 Rep 22 Posts Drives: 2008 BMW 125i e82 Join Date: May 2014 Location: Melbourne iTrader: (0)	125/128i with 135i axle back with genuine BMW Y-Pipe HELP! Hi guys need some help. I have an AUS e82 125i, Recently just bought a 135i axle back stock exhaust and a genuine BMW Y-Pipe to fit onto my stock 125i mids. After having taken it to the exhaust shop today I figured that they were not a direct bolt on as I had presumed. The angle of the Y-pipe is obviously different to my mids in both angle and diameter (5mm?), I'm presuming this was because the Y-Pipe was made to fit the 135i PE and N55 mids. It looks like a custom flange or adapter will need to be made to bring the two together. Also I have an opportunity to buy N55 mids which will obviously ease the pain of making any custom joints but have read up on some other posts that they will need adjusting in order to connect to the headers? If anyone has done this set up or something similar could you please explain the process you had to go through in order to make them fit. If you have pictures that would be even better. Thanks for your time
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07-12-2014, 12:00 AM	#2
andrey_gta Brigadier General 298 Rep 4,040 Posts Drives: 130i coupé ;) Join Date: Nov 2011 Location: Bimmerpost iTrader: (1) Garage List 2008 BMW 128i [10.00]	Yes n55 mids need adjusting too. I have seen some one in Germany make Y pipe and n55 mids work. They cut the ends of the n55 off and welded 125i diameter pipe with flange. This worked but i think it is crude. Locally i have heard of a Toronto 128i making n55 mids work without adjusting them. I think he did one of the following: A) cut the 125i header/exhaust manifold and make fit to n55 mids. B) create connector between 125i header and n55 mids - it would need to be up to 3 cm and would essentially work like this. one side had flange made for 125i header, the other is a flange made for 135i n55 mid pipes. This might be a little tight but i think it can work. The adapter needs to meet 125i header as male or female, the 135i side as the opposite. Gaskets of each car on both sides. The bolts of 125i header need to be Bent outward most likely to match n55 mids 128i/125i gasket - http://www.ecstuning.com/ES39474/ http://parts.bmwofsouthatlanta.com/p...107549447.html 135i gasket -http://www.ecstuning.com/ES40634/ http://parts.bmwofsouthatlanta.com/p...307553603.html Idea is like this - Part # 18111712064 or this - __________________ 128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is Last edited by andrey_gta; 07-12-2014 at 12:06 AM..
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