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The Story on Exhaust

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The following is a discussion lifted from the the First Fives Bulletin Board Archive.

NEW! - I've added pics of Bavaria exhaust manifolds to the end of the discussion. Actually, they are from a Euro E12, but whose counting.



Posted by Karl Koenig on January 29, 1999 at 00:43:05:
Anyone know if exhaust from a '89 535i would fir the E12 car? I once heard a rumor that exhaust from E28 cars would fit (among other E28 parts) Since I have the 535i engine, it only makes sense... ;-) karl


Posted by Wietse on January 29, 1999 at 02:07:01:
In Reply to: exhaust posted by Karl Koenig on January 29, 1999 at 00:43:05:
I think 2 generations of 5 series is too far of a stretch. The later e34 5's had the exhaust exit on the drivers side not the middle, like the e12 and e28. I am sure all the hangers are in different locations too. If you want a good exhaust try this: down pipes from the euro (early) 635csi $200 for both dual inlet cat, single exit (if you need one)$200 a 528e muffler (yes the e28 528e)$150 labor, pipe and go fast chrome tip $150 Have a muffler shop bend 2.5" pipe between the cat and muffler, have the muffler cut open to accept a 2.5 inch pipe, both inlet and outlet. You end up with a really nice system that is light and make good noise. All my prices are estimates.


Posted by Troy Rudolph on January 29, 1999 at 09:03:05:
In Reply to: Re: exhaust posted by Wietse on January 29, 1999 at 02:07:01:
Your idea sounds pretty good. Where would you install the oxygen sensor?


Posted by Cliff Robb on January 29, 1999 at 10:52:54:
In Reply to: Re: exhaust posted by Troy Rudolph on January 29, 1999 at 09:03:05:
The system that Wietse described is the exact make up of the Metric Mechanic System 300 that I paid way too much for before I knew better. It does sound good though. I also went for the MM "ported" dual exhaust manifolds that I believe come from either a 535 or a Bavaria. The porting amounts to nothing more than opening up the inlets of the manifolds to a round shape so that they are purposely larger than the exhaust ports on the head. This is claimed to have an anti-reversionary effect. The euro downpipes are 2"(50mm) as opposed to the stock single 40mm. As far as the O2 sensor, MM recommended just putting the bung in one of the downpipes. They supplied my down pipes with the bung on the front pipe. I was a little skeptical at first, but I checked into how O2 sensors work. Since they sense % of O2, not total quantity, if the engine is healthy & running right having the O2 sensor installed like that does not pose a problem. My car runs well set up this way, and my gas mileage as well as my O2 sensor readings (450MV avg.) are correct. You could probably do the system cheaper if you had the downpipes modified with a 2 to 1 collector, & then just get a hi-flow 2.5" cat. You have room in the stock muffler location for all different kinds of performance mufflers. This style of system will drop about 40lb. from the stock system. Deleting the resonator gives you that cool James Bond exhaust resonation sound as you go from about 2000 to 3000 rpm. I like it. Find out which muffler guy the hot rodders use in your town. He could probably bend you up a really nice system including custom downpipes and hi-flow cat. for $500 or less. If I had to do it again this is what I would do.


Posted by Wietse on January 29, 1999 at 11:21:25:
In Reply to: Re: exhaust posted by Cliff Robb on January 29, 1999 at 10:52:54:
Troy, I also handed Jim Rowe at MM a bunch of money for a System 300. When I realized what parts where used, I promised myself that no other e12er would pay the high $$ to MM if I could help it. Yes the system works well, but it was too expensive. W


Posted by Bill Bowes on January 29, 1999 at 20:21:49: In Reply to: Re: exhaust posted by Wietse on January 29, 1999 at 11:21:25: As these cars get older, spending $1000 on an exhaust system makes absolutely no sense. The suggestions made here DO make sense. Go to a speed shop and have them CUSTOM fabricate a system for your car. They will ask you what you want, and then they'll make it for you, usually for less than the BMW middle muffler costs. I have a BAVARIA. Been there, done that. And ANY idiot who does mufflers can install an O2 sensor. That's what they made torches for. I too chose the MM ported manifold idea. Except I did it myself with my trusty rotary tool. It works, and it works well. Let's face it. YOur choice is to do this or use hot, loud and rust prone headers. If you use your car alot, headers may not be the wise choice. If you race, this is your only choice. Bill Bowes


Posted by Frank Haas on January 30, 1999 at 11:15:28:
In Reply to: Re: exhaust posted by Bill Bowes on January 29, 1999 at 20:21:49:
Bill, Headers don't have to be loud or rust prone. I have some now three year old stahl headers on my driver. I Love-em. But do have them jet hot coated or they will rust, mine still look new. They are spendy though --if I remember right retail price $650 +150 for coating them. But they do look cool and are not any louder than stock euro manifolds. just my 02 cents worth Frank


Posted by Paul on January 30, 1999 at 15:28:18: In Reply to: Re: exhaust posted by Frank Haas on January 30, 1999 at 11:15:28: Ordinarily I read the comments or suggestions on the board, determine their accuracy and move on. But before any of you run out and build your own "System 300", I thought I'd let you know that Jim does not use a 528e muffler. I also know that HE can barely build his system for $500.00. Just food for thought.


Posted by Troy Rudolph on January 30, 1999 at 20:51:37:
In Reply to: Re: exhaust posted by Bill Bowes on January 29, 1999 at 20:21:49:
Bill, When are you going to give us some detailed directions on how to port those exhaust manifold? Please? Thanks Troy


Posted by Troy Rudolph on January 30, 1999 at 20:55:52:
In Reply to: Re: exhaust posted by Paul on January 30, 1999 at 15:28:18:
In the photo, it certainly looks like a 528e muffler. If you know it isn't, could you let us know what it is? Many thanks.


Posted by Peter Florance on January 31, 1999 at 20:03:34:
In Reply to: Re: exhaust posted by Troy Rudolph on January 30, 1999 at 20:51:37:
: Bill, : When are you going to give us some detailed directions on how to port those exhaust manifold? Please? Yeah, Bill. Quit holding out on us! Peter


Posted by Paul on January 31, 1999 at 00:27:41:
In Reply to: Re: exhaust posted by Troy Rudolph on January 30, 1999 at 20:55:52:
: In the photo, it certainly looks like a 528e muffler. If you know it isn't, could you let us know what it is? Many thanks. I shouldn't as it will very well come back to bite me in the you know what, never the less here it is. 524td.


Posted by Karl Koenig on February 01, 1999 at 22:20:12:
In Reply to: Re: exhaust posted by Peter Florance on January 31, 1999 at 20:03:34:
I saw the MM catalog, the porting job looks real straightforward. In fact, I've already started on the Bavaria manifolds i picked up. Thanks to all for the great info. That's what this board is all about


Posted by Karl Koenig on February 01, 1999 at 22:29:17:
In Reply to: Re: exhaust posted by Paul on January 31, 1999 at 00:27:41:
Wow, looks like I really hit hit the jackpot with this thread.

NEW! Here are the pics of the exhaust manifolds. The top is ported with a die grinder by yours truly. The bottom is stock.

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