Exhaust question - I may be crazy

[s8ilver]

So as some of you know, I got rear ended a while back in my 2.8 Coupe. I'm taking the car into the body shop tomorrow for a quote, and may just take the payout and deal with the bumper on my end. I had a thought about grabbing a Z3M bumper on eBay, painting to match (found one in my color but it's got a few marks), ditching the spare tire (I have AAA) and running a dual exhaust.

Does anyone know if a Z3M front section (with cats/resonators) will bolt up to M52TU downpipes? The car currently has stainless eBay headers, so no idea what mods (if any) PO had to do to rebolt up the stock exhaust. If the front section could be made to bolt up, I have the exhaust that came off my Z3M when I installed a Supersprint system after their incredible sale a while back (I actually bought the system locally for a bit less than the sale price so couldn't pass that up). If I could bolt up a front section and nab an M bumper, I'd only be in around $500 plus paint. According to some of you, I could even paint the bumper myself, which I'm not opposed to trying.

Thoughts? After studying the RealOEM diagrams, the flanges for the M front section look a bit more spaced out than the M52TU, but if that's all it is, could I just fab something to fit? Any other big issues to tackle? I don't have rear O2 sensors (deleted in tune), so I'd just plug the bungs behind the Z3M cats. Meow.

Other option is to just add a Y-joint after the current resonator and dual it that way.

[jrkoupe]

I know u dont want these thoughts but here goes:

y?....... y do it?....all that work.....

do u just like the quad look?

I never feel good about mods that dont really do anything or simply make a car look like something its not....

[MartyBtoo]

Don't non-M Coupes have a spare tire well right where the right side muffler has to go?

Marty

[BMW135]

I don't know if things just "bolt on" but all it takes is money or elbow grease... I can understand why you'd want it though. I LOVE the way the arse end of my car looks with the quad exhaust.

[s8ilver]

Is the editor tool not working here anymore? Whenever I click the pen icon, the forum deletes my posts by default. I replied to 3 posts, clicked edit and forum deleted it.

- - - Updated - - -

Don't non-M Coupes have a spare tire well right where the right side muffler has to go?

Marty

Yes, easily deleted. In fact, I've learned my spare tire doesn't even fit over my front M brakes, so unless I got a flat in the rear only, I'm using AAA.

I don't know if things just "bolt on" but all it takes is money or elbow grease... I can understand why you'd want it though. I LOVE the way the arse end of my car looks with the quad exhaust.

100% agree. My Z3 is very jealous of my Z3M.

I know u dont want these thoughts but here goes:

y?....... y do it?....all that work.....

do u just like the quad look?

I never feel good about mods that dont really do anything or simply make a car look like something its not....

No, I came here for opinions, and did preface by stating I may be crazy. I value your opinion.

M52TU is sort of a dual exhaust already...twin pipes from headers to resonator, and then a single pipe from resonator to a single muffler. Why not take advantage of what BMW may have initially wanted to be a true dual exhaust? I assume they did it as is to fit the spare tire.

My car is sort of M...suspension, brakes so not completely posing, right?

I also have six nice mufflers in my garage collecting dust and was looking for a project for two of them.

[jrkoupe]

I understand your points....

[s8ilver]

People do front M bumpers, mirrors, and grills all the time and no one seems to care. So they cut airflow, can't see as well, and get a flash of chrome for what purpose? I would say simply for looks. I'm am more after a better sound than looks, but I do admit I love the look of quad tips >>>> than a single dual exit. Let's see how much the insurance company tries to short me tomorrow and I'll go from there. Thanks all.

[Vintage42]

Don't non-M Coupes have a spare tire well right where the right side muffler has to go?

Don't all dual exhaust Z3s have no spare tire, and a battery well relocated to the center? Does converting to dual exhaust require a new section of trunk floor?

[Z-Thrizzle]

From my understanding the Z3M midsection should line up to the long-tube headers. I've noticed that part of the Z3M midsection exhaust is double walled. Suppose you can cut part of the mid-section and weld on connectors. This is probably what most people do with S52 long-tube headers with stock mid-section.

[Potes]

mufflers <


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[raubritter]

Does converting to dual exhaust require a new section of trunk floor?

yes... The Forbes diff mount reinforcement is pretty extensive 'surgery' anyway, so I ran the idea past Randy to convert my car to dual-muffler exhaust while he had things apart. He considered removing the spare tire well and replacing with sheetmetal, but then how to give the replacement sheet metal strength (needs stamping, bossing, whatever it's called)?

He happened to have a new, unused M trunkfloor lying around and was up to replacing mine with it. Turned out to be... fun... for him . I think it might be more of a project than OP is hoping, but I say it's worth a try... If you are a sheetmetal fabricator then maybe you could just remove the spare tire part and modify it to work...? Yes, Ms have just a big hole in the middle of the trunkfloor where the plastic battery box hangs from.

I love the look of quad exhaust on a Z3, and why not make my car look more like I want it to... Also took the badges off the back, and the look with the 'facelift' rear fenders is pretty exotic...

[s8ilver]

From my understanding the Z3M midsection should line up to the long-tube headers. I've noticed that part of the Z3M midsection exhaust is double walled. Suppose you can cut part of the mid-section and weld on connectors. This is probably what most people do with S52 long-tube headers with stock mid-section.

No idea if my headers are long tube, but I follow. I'll get under both cars and take measurements. It's nice to have an M parked next to the Z for reference.

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[ihm96]

The one thing I would mention to be careful of is the license plate. On our 2.8 Coupes its neatly tucked below the hatch on the bumper, but on M's there is no license cutout and it is slapped onto the hatch with some stupid US bumper guards. Looks way worse that way imo, the bumper is definitely the better spot for it

[BimmerBreaker]

Yeah where are you gonna put the plate? Gonna get an M trunklid too and swap key cylinders?

[ihm96]

Ugh that would be awful. If I ever get an M coupe honestly I'd probably do a reverse conversion and swap to the non M bumper and hatch. You would only have to modify the bumper really with new cutouts cause the floor would already be setup for it and those stupid US bumper things just really grind my gears. Even newer cars get screwed with those sometimes, like the Euro version of the AMG GT rear bumper is way sexier and cleaner

Yeah where are you gonna put the plate? Gonna get an M trunklid too and swap key cylinders?

[DiqueTico]

The license plate wouldnt be a huge issue, just mount it on the rear bumper(or tow hook mount) and figure out lighting for it if your state requires it. This is what @mplicit did.
The work to figure out would be the trunk floor if you want to run an OE style exhaust.

[Tigershark48]

Why not just upgrade from your Z3 to an M? Even after all the work and money to change yours, you still wouldn't have an M.

[s8ilver]

Why not just upgrade from your Z3 to an M? Even after all the work and money to change yours, you still wouldn't have an M.

I have an M.

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[Tigershark48]

Cool! Just read your profile. Good luck with your Z3. Sounds like some challenging work.