E36M3 original catback on E30

[static]

Hey all

just had my S50 swap done but still with original exhaust.

I plan to do all custom dual 2.25" SS piping with highflow magnaflow dual-in-dual-out cats from headers to the catback and also plan to use the original E36M3 catback for now (got it for very cheap, heavy i know but helps with better weight distribution as S50 is heavier). I do this because i want to got with an aftermarket catback designed for E36M3 down the road without any modifications

So the question is, would the catback fit the E30 without cutting? (can i get away with just custom brakets) or will need to cut pipes?

Any help and advice is welcome

Thanks
Alex

[1990m3]

i just went through this about two weeks ago. I had a cat section that I cut the pipes from that go up through the subframe. Mounted the cat and had the exhaust shop make custom pipes to meet up with the headers and custom chop the muffler and hang it. I used the stock trans brace for the front, that worked very very well, and i used the stock rear e30 hangars on the e36 muffler, but I still have to put two hangars up the in middle so it doesn't sag. It's tight and quiet as is, but sags a little in the middle.

good luck

[Beej '86 325es]

I asked C///M about this a while ago, this is what he said:

To clarify, I'm using S52 headers, cats, and E36 M3 Stromung rear exhaust.

So the exhaust is completely e36 M3 without any modifications to the pipes, essentially a perfect fit.

For what did have to be done. Plenty of banging and bending of the heatshielding that is above the catalytic converters to that the exhaust fit without touching anything.

Hangers - all custom. You will need to weld on or create some brackets to attach to the muffler and cat-back piping that will line up with the standard e30 mounting locations. Overall, it takes some time but is a fairly simple process.

[1990m3]

i don't know how his fit like that, mine definitely does not. I also used S52 headers, maybe my large e30 m3 swaybar is getting in the way. I also run stock offset control arm bushings, not those little THR ones that have extra clearance.

Dave

[static]

yes i am also curious about whether my offset m3 CABs will get in the way.
Anyone that succeded in installing a E36 catback on an e30, has any pictures to show how that was implemented?
I do want to put a Stromung down the road, anyone knows if the catback configuration of piping is the same for stock E36M3 and Stromung(for E36M3)?

also how loud will it be with stock E36M3 muffler, dual-in-dual-out Magnaflo highflow cats and 2.25" SS piping all around?

Thanks
Alex

[Beej '86 325es]

Where are you finding dual inlet/dual outlet catalytic converters?

[static]

local place has them
not sure where they are getting them

Alex

[DanGillan]

flowmaster makes a dual in dual out cat, that's what i will be using.

[325Projectz]

Dual In Dual Out Cat

[C ///M]

I should add, the complete e36 exhaust worked with the e36 M3 stromung muffler because it's so much smaller than the stock e36 m3 peice.

A stock e36 M3 muffler on the e30 just isn't worth the trouble. I don't care if it's heavy, but it's just too big.

If you want to use a stock e36 midsection, you need Treehouse's CAB's, otherwise you'll have to modify the piping because the stock CAB lollipops are too big. Anyway, within the last month or so, I had a shop heat up the pipes a little bit to get the exhaust farther away from the ground and I modified the custom hangers/brackets a bit to make sure it's nice and secure.

Either way, I use a complete OBDII exhaust (dual pipe all the way with o2 ports plugged) and it wasn't very difficult to fit. Went much faster than making a complete custom system.

One last bit of info, when I first started, I had a '95 M3 midsection. I only used that for a few months and then upgraded to the '96+ M3 midsection because its dual pipe all the way, and I easily felt a difference. If you're gonna use a stock e36 midpipe, get the OBDII dual pipe system and plug the o2 ports, it flows waayy better than the OBDI pipe.

EDIT: Current tip placement:

[325Projectz]

Wow, those tips look very nice.

[C ///M]

Thanks, sounds even better combined with the replica GruppeM intake.

[1990m3]

chris - show us some pics from underneath the car. i'm running obdI midpipes right now. how noticable is the difference between obdI and obdII? Do you have any hard data? I should have bought the obdII, don't know what I was thinking

[C ///M]

I'll try to get some pics from underneath sometime.

Unfortunately no hard data, but definitely a difference you can feel midrange to up top.

[Low Level E30]

Either way, I use a complete OBDII exhaust (dual pipe all the way with o2 ports plugged) and it wasn't very difficult to fit. Went much faster than making a complete custom system.

Hey Chris --- Which engine mounts are you using? I want to mount the motor as low as possible, and still be able to use the stock OBDII setup.