M635 exhaust pieces

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ericono
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M635 exhaust pieces

Post by ericono »

I am trying to figure out the part number for the correct middle stretch of the exhaust system for an '85 M635, without CAT. When I look in RealOEM I don't see it shown. I see the exhaust manifold and the middle and rear mufflers, but I don't see the piece that connects those 2 things. If I look at the exhaust with CAT, I can see the CAT piece that would fill the same location, but I need the non-CAT version.

If, by chance, someone has that piece and they no longer need it, please let me know...

Any help is most appreciated!

Eric
'85 M635, '00 528iT, '98 Z3
cjarvis
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Re: M635 exhaust pieces

Post by cjarvis »

I am pretty sure that parts #1 and #2 here: http://www.realoem.com/bmw/enUS/showpar ... Id=18_0084 are the complete non-cat system from the headers back. Its been a few years since I replaced the original exhaust on my car, but memory says the front muffler was really long. The Stebro on the car now just has two pieces as well.
Craig in MI
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ericono
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Re: M635 exhaust pieces

Post by ericono »

Thanks Craig. I appreciate you replying back. I looked at that image, and others, on RealOEM and looked at my car, and I believe there is still a piece between what is shown and the end of the headers (manifolds). Unfortunately my exhaust was hacked up by a PO who had the thing welded all the way through (to accomplish this it looks like the welder had to leave the exhaust downward more than desired). I am in the process of trying to put it back to original where it bolts together and tucks back into the underside of the body nicely.

If possible, can someone with an M635 peak under their car and see what their factory system looks like?

Thanks again,

Eric
'85 M635, '00 528iT, '98 Z3
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M6smitten
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Re: M635 exhaust pieces

Post by M6smitten »

Piece #1 in that graphic IS the resonator/center piece.
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Brucey
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Re: M635 exhaust pieces

Post by Brucey »

ericono wrote: If possible, can someone with an M635 peek under their car and see what their factory system looks like?
Maybe you could post a photo of what you have at present?

The factory system looks very much like the pictures on realoem; the down pipes bolt to the centre silencer just near the gearbox hanger bracket. There are two three-bolt flanges, one of which defines the length of the assembly, and the other of which can telescope slightly so that the angle of the front vs the rear section can be adjusted if necessary.

Normally the rest of the system is hung and adjusted for height etc, and then the three-bolt flanges are the last pieces to be fully tightened.

If someone has welded the pipes where the three-bolt couplings usually are you have a load of work ahead of you to make it stock again; you need to obtain flanges, and then to weld flared sections to the pipe ends so that the joints can be made in the usual way.

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whiskeydry
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Re: M635 exhaust pieces

Post by whiskeydry »

The early original M635 exhaust systems had the front and back boxes welded together as stock with a sleeve which became NLA. Both the original systems fitted to my car had the welded sleeves. Here are some pictures of my last original system (I now have a Supersprint system fitted). There is a system for sale on UK Ebay ( http://www.ebay.co.uk/itm/222085718451 ) from a Highline M635 that had the clamps fitted. Change over is shown in RealOEM as being Feb 1989. I have included a photo of the front box but your manifold to front box fitting might be different from mine as my car is RHD so does not have the snakes manifold.
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greencsi
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Re: M635 exhaust pieces

Post by greencsi »

Hi Eric, in this post from M5 board (http://www.m5board.com/vbulletin/e28-m5 ... 5-a-5.html), the PO has a picture and the invoice (in the middle of the post) for the complete set matching RealOEM item 1 and 2. I think item 1 and 2 are all you need.

Good luck.
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ericono
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Re: M635 exhaust pieces

Post by ericono »

Sorry for the delay. thanks for all the replies everyone. The light bulb went off yesterday, and I think I see the disconnect. I couldn't get any meaningful pictures of my system so I searched around on the web and found a couple of pics I think will help. The photos in the link from greencsi really helped me put it all together. I think the confusion was coming from the fact that it looks like I have the center resonator and rear muffle assembly for a catalytic converter setup as that was not a 2 piece assembly. I found a photo online of what it looks like (see top photo).
https://goo.gl/photos/bNKAUXwBNKgkkgeB6
If you look at the bottom photo you'll see how this aftermarket dual cat set up bolts between the center resonator and the end of the headers. I added some red lines to show where my current system has been cut and welded.

Here is a photo of the true non-cat version (from the post above).
https://goo.gl/photos/vLxa2p6YVynjrkLa7

Sorry I've only got a link to the photos right now. Will try and get the photos embedded for easier reference in the future.

I've got a new set of headers coming, with the proper flanges on it, and my center resonator/rear muffler assembly is only a few years old with the only modification being the very end with the flanges cut off. I was originally thinking I could get a new/used "center" section (that I realize now never existed as I envisioned it in my head) and get a muffler shop to just weld back on the provisions needed for the flanges before the center resonator.

It looks like now my options are to get that center dual cat assembly shown above and get flanges added before the center resonator of my existing exhaust following my original plan. Option 2 would be to get all new center and rear mufflers, as shown in the last photo above. The issue here is I don't know if they are actually available from BMW (or anywhere else) as it seems getting parts like this out of them is difficult at best.

Thanks for all the help guys!

Eric
'85 M635, '00 528iT, '98 Z3
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Brucey
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Re: M635 exhaust pieces

Post by Brucey »

ftfy?

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ericono
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Re: M635 exhaust pieces

Post by ericono »

Thanks Brucey.

Sorry, but what is "ftfy?"

Eric
'85 M635, '00 528iT, '98 Z3
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Re: M635 exhaust pieces

Post by Alpinacsi »

fixed that for you
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greencsi
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Re: M635 exhaust pieces

Post by greencsi »

ericono wrote:Sorry for the delay. thanks for all the replies everyone. The light bulb went off yesterday, and I think I see the disconnect. I couldn't get any meaningful pictures of my system so I searched around on the web and found a couple of pics I think will help. The photos in the link from greencsi really helped me put it all together. I think the confusion was coming from the fact that it looks like I have the center resonator and rear muffle assembly for a catalytic converter setup as that was not a 2 piece assembly. I found a photo online of what it looks like (see top photo).
https://goo.gl/photos/bNKAUXwBNKgkkgeB6
If you look at the bottom photo you'll see how this aftermarket dual cat set up bolts between the center resonator and the end of the headers. I added some red lines to show where my current system has been cut and welded.
Hi Eric, the single piece setup that you currently has (with center resonator and rear muffler in one) is for the U.S. M6 (part# 18101310759). It used to be a two pieces system (part# 18129068562 and 18129068565). This U.S. system uses a two-bolt flange setup and the Euro system uses a three bolt flange setup. This may explain why your current system is welded.
ericono wrote: It looks like now my options are to get that center dual cat assembly shown above and get flanges added before the center resonator of my existing exhaust following my original plan. Option 2 would be to get all new center and rear mufflers, as shown in the last photo above. The issue here is I don't know if they are actually available from BMW (or anywhere else) as it seems getting parts like this out of them is difficult at best.
If you go with Option 2, both 18122225082 and 18121309004 showed up on BluntTech.com. However, you will have to double check with them to be sure they can order it for you. You also need a couple of 18307560777 clamps between your center and rear mufflers.

Eric, by any chance, if you decided to let your currently U.S. single piece go, you can email me about miles of usage and condition. I would like to buy it from you. I am interested in a rear muffler which I no longer can get it as a standalone piece without the center muffler. I will be in Greenville/Geer on 4/23. Email me if you want to get together for coffee. Thanks.
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