does a stock 135i catback exhaust fit 128i?

neverdone · 07-14-2014, 07:18 PM

I've searched and I'm not getting a proper answer, can anyone tell me if it's a direct bolt on? Is it a worthwhile mod for a 128i?

631twentyeighteye · 07-14-2014, 07:23 PM

It's not bolt on, you'll need an exhaust shop to modify your stock mids to bolt up to 135i axleback(they'll need one to line it up).

andrey_gta · 07-14-2014, 07:24 PM

Its not a bolt on because the 128i Performance exhaust requires a cut & clamp.

The 135i catback will be simmilar, I belive someone recently mentioned that 135i pipe is actully a bit larger than 128i so the weld or clamp needs to accommodate that.

Alternatively you can make the 135i catback meet at resonator with a new custom flange

neverdone · 07-14-2014, 08:37 PM

How much bigger is the 135 exhaust than the 128, anyone know?

tuphdc · 07-14-2014, 09:26 PM

135i uses 3" piping
128i uses 2.5" piping

as far as I know

neverdone · 07-14-2014, 09:35 PM

So not a bad upgrade. Anything bigger and it will be overkill for back pressure I guess...

MarkkyyMan · 07-14-2014, 11:28 PM

Read up on exhaust scavenging.

Rarely does a N/A motor without head/cam modifications benefit at all from larger exhaust piping especially the further away you go from the collectors.

TheSt|G · 07-15-2014, 06:50 AM

Quote:

Originally Posted by neverdone

So not a bad upgrade. Anything bigger and it will be overkill for back pressure I guess...

It's not going to change anything, nor is back pressure important for anything good.

chris82 · 07-15-2014, 08:22 AM

So other than cutting and welding the new piece. The 135 muffler fits fine and hooks into the original locations?

BTXP.XD · 07-15-2014, 08:28 AM

I got a question now, does the stock 135I axleback directly match up with the 128I exhaust. I know that some weilding would be needed to make that size difference in piping fit but besides from that, would it just go straight under the car?

Kgolf31 · 07-15-2014, 08:36 AM

Quote:

Originally Posted by Illestfoigs

I got a question now, does the stock 135I axleback directly match up with the 128I exhaust. I know that some weilding would be needed to make that size difference in piping fit but besides from that, would it just go straight under the car?

IIRC the bends are indeed the same, just need modifications to make the headers bolt up correctly to stock headers.

chris82 · 07-15-2014, 08:51 AM

Quote:

Originally Posted by Kgolf31

IIRC the bends are indeed the same, just need modifications to make the headers bolt up correctly to stock headers.

How do the headers come in to play? Lol

Kgolf31 · 07-15-2014, 09:02 AM

Quote:

Originally Posted by Chrisar82

How do the headers come in to play? Lol

Sorry...I read cat-back not axle back.

IMO I don't see why you'd waste time on a 135i modification. Do a muffler delete or something similar....much cheaper and IMO better in the end. I'm going to try to get some videos up from mine

chris82 · 07-15-2014, 10:17 AM

Quote:

Originally Posted by Kgolf31

Sorry...I read cat-back not axle back.

IMO I don't see why you'd waste time on a 135i modification. Do a muffler delete or something similar....much cheaper and IMO better in the end. I'm going to try to get some videos up from mine

I'm interested in the muffler delete but I just don't want it to sound like shit.

BTXP.XD · 07-20-2014, 11:04 PM

so um, does anyone noe if 135I axleback fit a 128I stock piping

andrey_gta · 07-20-2014, 11:17 PM

Quote:

Originally Posted by Illestfoigs

so um, does anyone noe if 135I axleback fit a 128I stock piping

There will be a difference. 135i pipe is close to 3 inches, maybe 2.75 inches @ exhaust. I say this because the perv owner of my exhaust stated that its not 3", its a bit less.

So measure your 128i where it meets the muffler.
You will know what needs to be done by a shop.

flinchy · 07-21-2014, 04:39 AM

Quote:

Originally Posted by tuphdc

135i uses 3" piping
128i uses 2.5" piping

as far as I know

Nope 135i is 2.5", hence the '3"' dp's have a taper at the midpipe flange

Ed: if you mean axleback piping.. My 130i looks to be the same size, but no mid cats

skyscraper_g80 · 07-23-2014, 05:28 AM

It required a bit of welding, but I've just had a stock 135i back box fitted to my 130i (as well as the BMW Performance Y-pipe from the 135i)

neverdone · 08-30-2014, 04:28 PM

Quote:

Originally Posted by evolution42

It required a bit of welding, but I've just had a stock 135i back box fitted to my 130i (as well as the BMW Performance Y-pipe from the 135i)

How does it sound? Any clips?

mechavore884 · 08-30-2014, 09:54 PM

Quote:

Originally Posted by BTXP.XD

so um, does anyone noe if 135I axleback fit a 128I stock piping

in a way it does, I just sleeved it then welded it in and its been flawless

skyscraper_g80 · 08-31-2014, 03:36 AM

Quote:

Originally Posted by neverdone

How does it sound? Any clips?

Not of the exhaust specifically, but you can hear it in a recent track day I went to. Note the pops and crackles when coming into the pits

http://www.youtube.com/watch?v=_k2WklyQVec&t=55m44s

DietTab · 08-31-2014, 03:48 AM

Quote:

Originally Posted by tuphdc

135i uses 3" piping
128i uses 2.5" piping

as far as I know

135i is only 2.75" axleback and 2.25" midpipes

07-14-2014, 07:18 PM	#1
neverdone Major 327 Rep 1,397 Posts Drives: X5, 335, Ford Lightning, 63 me Join Date: Jun 2014 Location: calgary iTrader: (0)	does a stock 135i catback exhaust fit 128i? I've searched and I'm not getting a proper answer, can anyone tell me if it's a direct bolt on? Is it a worthwhile mod for a 128i?
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07-14-2014, 07:23 PM	#2
631twentyeighteye Colonel 198 Rep 2,239 Posts Drives: 08 335i Join Date: Aug 2012 Location: Long island iTrader: (7)	It's not bolt on, you'll need an exhaust shop to modify your stock mids to bolt up to 135i axleback(they'll need one to line it up). __________________ 08 e93 335i MT
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07-14-2014, 07:24 PM	#3
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]	Its not a bolt on because the 128i Performance exhaust requires a cut & clamp. The 135i catback will be simmilar, I belive someone recently mentioned that 135i pipe is actully a bit larger than 128i so the weld or clamp needs to accommodate that. Alternatively you can make the 135i catback meet at resonator with a new custom flange __________________ 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
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07-14-2014, 08:37 PM	#4
neverdone Major 327 Rep 1,397 Posts Drives: X5, 335, Ford Lightning, 63 me Join Date: Jun 2014 Location: calgary iTrader: (0)	How much bigger is the 135 exhaust than the 128, anyone know?
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07-14-2014, 09:26 PM	#5
tuphdc Second Lieutenant 20 Rep 212 Posts Drives: 09 BMW 128i 6MT Sport Pkg Join Date: Apr 2013 Location: King of Prussia, PA iTrader: (0)	135i uses 3" piping 128i uses 2.5" piping as far as I know
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07-14-2014, 09:35 PM	#6
neverdone Major 327 Rep 1,397 Posts Drives: X5, 335, Ford Lightning, 63 me Join Date: Jun 2014 Location: calgary iTrader: (0)	So not a bad upgrade. Anything bigger and it will be overkill for back pressure I guess...
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07-14-2014, 11:28 PM	#7
MarkkyyMan Captain 38 Rep 701 Posts Drives: 2010 BMW 128i Join Date: Dec 2009 Location: Indiana, U.S. iTrader: (0)	Read up on exhaust scavenging. Rarely does a N/A motor without head/cam modifications benefit at all from larger exhaust piping especially the further away you go from the collectors.
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07-15-2014, 08:22 AM	#9
chris82 Brigadier General 827 Rep 3,856 Posts Drives: 128i Join Date: Aug 2012 Location: NY NY iTrader: (8) Garage List 2009 BMW 128i [9.80]	So other than cutting and welding the new piece. The 135 muffler fits fine and hooks into the original locations?
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07-15-2014, 08:28 AM	#10
BTXP.XD NOOOOB 9 Rep 192 Posts Drives: 2012 128i COUPE Join Date: May 2013 Location: TORONTO iTrader: (0)	I got a question now, does the stock 135I axleback directly match up with the 128I exhaust. I know that some weilding would be needed to make that size difference in piping fit but besides from that, would it just go straight under the car? __________________ A COMPLETELY STOCK CAR!
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07-20-2014, 11:04 PM	#15
BTXP.XD NOOOOB 9 Rep 192 Posts Drives: 2012 128i COUPE Join Date: May 2013 Location: TORONTO iTrader: (0)	so um, does anyone noe if 135I axleback fit a 128I stock piping __________________ A COMPLETELY STOCK CAR!
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07-23-2014, 05:28 AM	#18
skyscraper_g80 First Lieutenant 371 Rep 339 Posts Drives: 2022 G80 M3 Competition xDrive Join Date: Sep 2005 Location: Sydney iTrader: (0) Garage List 2022 BMW M3 Competi ... [0.00] 2006 BMW 130i M-Sport [8.50] 2007 BMW 335i M-Sport [10.00]	It required a bit of welding, but I've just had a stock 135i back box fitted to my 130i (as well as the BMW Performance Y-pipe from the 135i)
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