Muffler/tailpipe exhaust gasket rings?!?!

[daytonabitch]

I've been working on my cars for over 50 years but my M3 is my first BMW, and every time I think I'm on the home stretch of my rear-end rebuild, it throws another curve at me.
I'm at the stage of re-installing the muffler, and in preparation I bought two new gasket sealing rings. Didn't realize each of the two rings is unique. The new ones I have are metallic (ie magnetic) and appear to fit snugly when slid onto the non-flared end of the forward pipe on the passenger side, but seem to be wider than the one currently rusted in place on that pipe. On the other side, the original ring, which I presume gets clamped in place between the flared ends of the two pipes on the driver's side, is not metallic. Could it be copper? And can it be re-used?
Any wisdom would be appreciated!

[Carpy2]

P/N's #21 and #22 in this diagram for '95 M3s. #21 is now an "asbestos free" version that superseded a presumably non-asbestos free version? (RealOEM says the same thing happened with my '96+ M3). Maybe explains your mysterious copper looking ring.

I've always reused mine. If you notice a leak or they are particularly rusty/gross, it won't hurt to replace them.

[Braymond141]

18111723721 (#21) is gasket that sits on the outside diameter of the midsection on one side.
18111719446 (#22) is the metal ring that bridges the female to female gap between mid section and muffler section on the other side.

You need one of each IF yours are damaged. You almost never have to replace these parts, but that's likely a California luxury.

[daytonabitch]

Many thanks to you both. The new ones I have are #21 and the old one of that type did need replacing so that's done. And #22 for the other side still looks good so I'll re-use it.
Thanks again
PS that M3 muffler is a heavy sucker isn't it?

[blckstrm]

Many thanks to you both. The new ones I have are #21 and the old one of that type did need replacing so that's done. And #22 for the other side still looks good so I'll re-use it.
Thanks again
PS that M3 muffler is a heavy sucker isn't it?

Yes, it is remarkably heavy. I get compliments all the time on how my exhaust sounds - even from other long time E36 M3 owners - who are always surprised to learn it's the stock exhaust.

But man, it is crazy heavy.

I just got headers after having the car for 10 years and was surprised to learn the midpipe is double walled, and that BMW uses a high quality but very heavy gauge for the pipe in general. Which does explain the weight, but also explains the general lack of trouble with rusty pipes.

[JitteryJoe]

I replaced my muffler with a SuperSprint version and it was "damn, this this is light compared to that heavy monster I pulled out".

[NeilM]

I replaced my muffler with a SuperSprint version and it was "damn, this this is light compared to that heavy monster I pulled out".

Same here. Basically, any aftermarket cat back system will be much lighter than stock, and in fact that's the main advantage. Power increase is minimal. Sound quality is in the ear of the beholder. ;-)

Neil

[notMpowered]

Yeah I honestly loved the stock sound. I couldn't get past the looks and the weight though. The eisenmann looks great, saved about 30# and sounds very similar, just a touch louder and raspier.

[BMWManiac]

Many thanks to you both. The new ones I have are #21 and the old one of that type did need replacing so that's done. And #22 for the other side still looks good so I'll re-use it.
Thanks again
PS that M3 muffler is a heavy sucker isn't it?

I just replaced my driveshaft and absolutely hate installing the stock midsection/headers + muffler. The muffler is not only heavy, but seems to love to rotate. I finally figure out that the easiest way for me to do this is to put the muffler on the jack and jack it up a bit, install the passenger side that actually inserts into the midsection, and then rotate the muffler. What a pain to do this by yourself, foot on the jack, jackstands, etc.....

[pizzaman09]

If you think an e36 M3 exhaust is heavy, check out an e39 M5 exhaust. Dual exhaust the length of the car with four large scuba tank sized resonators at the back.

[nick325xit 5spd]

If you think an e36 M3 exhaust is heavy, check out an e39 M5 exhaust. Dual exhaust the length of the car with four large scuba tank sized resonators at the back.

One time I was helping a buddy pull his E39 M5 exhaust. We were on a lift, lowering it with a trans jack, so easy stuff. Except.... He wasn't paying attention and the trans jack (HF special) jammed the angle adjuster knob on his finger on the pressure release knob. So he basically ended up with most of the weight of the exhaust on his finger. I was standing at the other end, holding up his exhaust just helplessly watching him work it out. (To be clear, while very painful, no actual injuries. If we'd had to drop the exhaust to get him out, we could have.)

[daytonabitch]

BMWManiac, Yup, been there done that. I have my car up on a mid-rise lift, and used a pipe stand to support the muffler, while a cross-bar on the lift was conveniently positioned to support the forward end of the pipes. I was pleasantly surprised how easily it all went together.

[Hagasan41]

Picking this up to install my new Eisenmann exhaust and some other hardware bits to refresh the system. Planning to use clamps vs welding. Anyone have a recommendation on exhaust clamps, size, brand, etc?

https://www.turnermotorsport.com/p-374460-muffler-installation-kit/

[bmwstephen]

Picking this up to install my new Eisenmann exhaust and some other hardware bits to refresh the system. Planning to use clamps vs welding. Anyone have a recommendation on exhaust clamps, size, brand, etc?

https://www.turnermotorsport.com/p-374460-muffler-installation-kit/

I tried 2 different clamps and always found some trace of a leak. ended up welding to solve the issue. Also a couple of observations.

Be sure to spec out staggered tips to match with the factory setup. the larger the tips you get, the less room you have to center it against the valence opening and play with fitment. I already burnt a smaller discrete area on my valence running the 70MM tips the 1st time I mounted it because my rubber hangers were shot and there was a lot of play when the car is in motion.


When test fitting or centering the exhaust, make sure to be aware of its clearance to the driver side rear tire. The s52 muffler had a provision for this when they went with 245 width for 96+ cars whereas most aftermarket mufflers (with the exception of AA, UUC, Dinan) don't account for this



Me running a 235 width tire gave me 1 inch clearance. I can only imagine having to run spacers on anything beyond factory 245 width or the muffler pinch weld will rub against your inner sidewall




The Eisenmann muffler is dimensionally smaller than the factory (width and height-wise) so you will need to get creative on extending the muffler clamps on each side by the pinch weld. Or you risk prematurely wearing down the rubber hangers because it would get pulled inwards. I ran a longer bolt and a few nuts to bridge the clamp further inward instead

[Hagasan41]

Thank you for the heads up on the install. Yes, I ordered the 76mm staggared tips and sadly, haven't even opened the box from IND. LOL

I may simply decide to take it the local BMW performance shop and have them install it and TIG weld it. Do you think their is any benefit to the hanger inserts FCP offers?
https://www.fcpeuro.com/products/bmw...revshift-peim3

[bmwstephen]

Thank you for the heads up on the install. Yes, I ordered the 76mm staggared tips and sadly, haven't even opened the box from IND. LOL

I may simply decide to take it the local BMW performance shop and have them install it and TIG weld it. Do you think their is any benefit to the hanger inserts FCP offers?
https://www.fcpeuro.com/products/bmw...revshift-peim3

tried those, did not give the rubber hangers enough flex when mounting the eisenmann

[CKr]

For my Eisenmann I used of these lap joint clamps, but like bmwstephen said, they will leak. I’m not proud of this, but I ended up wrapping foil around exhaust, just under the clamps, and that seemed to get rid of the small leaks I had. There’s actual exhaust wrap you can buy, presumably for this reason, I just haven’t had the drive to redo my clamps. I don’t trust a shop to make sure everything is oriented and lined up correctly before welding, so I just stuck with the clamps.

@bmwstephen, I’m glad you mentioned extending the clamps, up until now I thought I was crazy for doing the same. I had the muffler on and off my car probably 10 times trying to get it installed where the rubber mounts weren’t stretched. Or where the exhaust would push to one side as it warmed up (it expands and shifts rearward a decent amount, which is why the BMW mounts are the way they are). I even reached out to IND to see if they had instructions from Eisenmann to properly mount it.

[bmwstephen]

If you have it aligned via clamps already the i recommend taking it to the exhaust shop to weld from there. Thats what i did. Clamps were used as a place holder and then the shop loosened and slid back one clamp at a time, tack weld the connecting pipe in position. He did it one side at a time before removing the exhaust and doing a thorough weld around the pipes. In fact only charge me half an hour cause he didnt have to spend time aligning it