BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      09-06-2012, 04:17 PM   #1
E30 Racer
Second Lieutenant
E30 Racer's Avatar
United_States
6
Rep
293
Posts

 
Drives: '11 1M, '99 540i/6, '89 325is
Join Date: Aug 2011
Location: Ohio

iTrader: (1)

Aftermarket midpipe to OE catback question

Presumably, the post-merge aftermarket pipe diameter is larger than that used by BMW. How does this affect the ability to join them without replacing the coupler on the catback side?
Appreciate 0
      09-06-2012, 06:14 PM   #2
Smiley1175
Captain
Smiley1175's Avatar
Australia
7
Rep
677
Posts

 
Drives: 1M
Join Date: Jun 2011
Location: Melbourne

iTrader: (0)

I'm not sure if I fully understand your question but every aftermarket mid pipe I've seen is same diameter and bolts straight on to oe exhaust. The changes are usually the removal of the cats and/or the resonator. Not a change in diameter.
Hope this helps.
Appreciate 0
      09-06-2012, 07:55 PM   #3
E30 Racer
Second Lieutenant
E30 Racer's Avatar
United_States
6
Rep
293
Posts

 
Drives: '11 1M, '99 540i/6, '89 325is
Join Date: Aug 2011
Location: Ohio

iTrader: (1)

This is not the case for Akrapovic. The base OD if their gasket (i.e., at the small end of the taper) is nearly as large as the maximum diameter if the OE flange. No way I'd get a reliable seal.
Appreciate 0
      09-16-2012, 12:23 PM   #4
dlai
New Member
0
Rep
11
Posts

 
Drives: BMW M3
Join Date: Mar 2011
Location: Australia

iTrader: (0)

It's odd that you have this issue. I found that usually when it's bigger diameter, they end up being tappered down when it gets closer to the flange. Does this happen to your Akrapovic?
Appreciate 0
      09-17-2012, 08:39 PM   #5
E30 Racer
Second Lieutenant
E30 Racer's Avatar
United_States
6
Rep
293
Posts

 
Drives: '11 1M, '99 540i/6, '89 325is
Join Date: Aug 2011
Location: Ohio

iTrader: (1)

Quote:
Originally Posted by dlai
It's odd that you have this issue. I found that usually when it's bigger diameter, they end up being tappered down when it gets closer to the flange. Does this happen to your Akrapovic?
Unfortunately that is not the case here. In their defense, I doubt Akrapovic ever intended their midpipe to be used with anything but their axle back exhaust, whose inlet is quite a bit larger than that used by BMW or many aftermarket offerings. Oh well, I'm having Burns Stainless fabricate an adapter.
Appreciate 0
      10-19-2012, 10:52 PM   #6
E30 Racer
Second Lieutenant
E30 Racer's Avatar
United_States
6
Rep
293
Posts

 
Drives: '11 1M, '99 540i/6, '89 325is
Join Date: Aug 2011
Location: Ohio

iTrader: (1)

Update: the adapter from Burn Stainless arrived today. I designed the part, sent them the Akra midpipe with a new new graphite sealing gasket, and they fabricated it. As always, their quality was outstanding, with welds that could pass for robotic. Assembly was uneventful, although I'd like to find some springs that will allow me to use the OE flange bolts.









I'll post a sound clip soon, but my initial impression is that cold start, idle, and revving aren't that much louder than stock. Since I haven't actually driven the car, I cannot comment on interior volume at speed or drone yet.
Appreciate 0
      10-28-2012, 04:35 PM   #7
E30 Racer
Second Lieutenant
E30 Racer's Avatar
United_States
6
Rep
293
Posts

 
Drives: '11 1M, '99 540i/6, '89 325is
Join Date: Aug 2011
Location: Ohio

iTrader: (1)

On ramps, but the sound is pretty accurate.


Last edited by E30 Racer; 10-28-2012 at 04:55 PM.
Appreciate 0
      10-28-2012, 07:54 PM   #8
ozinaldo
Brigadier General
ozinaldo's Avatar
Portugal
46
Rep
3,053
Posts

 
Drives: 1M
Join Date: Jan 2011
Location: Lisbon, Portugal

iTrader: (0)

Quote:
Originally Posted by E30 Racer View Post
On ramps, but the sound is pretty accurate.

Like you've mentioned before what I hear from this clip is not too different than the stock soundwise, just a notch louder. Definitely closer to a N55 mid sound than a Maddad. More burbles.
__________________
"The mark of a great car is one whose overall competence exceeds what you should expect from its individual components and the 1M does just that", Chris Harris.
BMW 1M-SOLD-: TECH: Evolve Race+N55mids, Evolve IC, Michelin PSS, ER cp, aFe filter, CDVx, Vorshlag camber plates, BMS OCC EXTERIOR: trunk spoiler, blacklines, black grills, IND goodies INTERIOR: Alcantara steering wheel, steel pedals, custom mats, MPower e-brake.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:52 PM.




1addicts
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST