Z3 M52 in 1991 318is (California BAR)

[Codym42]

I have the same setup as MJ. I also have a '97 Z3 m52 in my e30 and am using the stock manifolds. I went through the same search and couldn't figure out why the part numbers were different from an e36. Markert Motor Works used a Synchro Design Works downpipe on mine and had no issues fitting it to the Z3 manifolds.

[mjweimer]

I used the Syncro Design Works downpipe which is designed to work with the stock FCAB's and ends in an S-bend so you can attach you own custom exhaust (they also sell a complete front to back exhaust but I have other plans).


Since you are going to do a BAR cert and need a factory center section, I think you will be limited on clearance and will need to run Treehouse style FCAB's. I have no specific experience with this but many on this forum will and there should be some documented installs.




MJ

That's great news!! I gave up hoping that someone would chime in as it seems like Z3 information is limited. Thank you!

This means it'll fit like the e36 ones, which means I probably need to get some Treehouse style FCABs then?

[Jean]

Even if, say I BAR it as an e36 swap rather than a Z3 for purely exhaust fit reasons?


Well, the thing is, they're going to ask for proof it's a California emission certified engine its a very recent rule that's been put into place and honestly I can't say what the ref is going to do if you have e36 stuff under there. You could always call and ask a ref, they're very helpful. I know an OBD2 e36 has 4 oxygen sensors, one in each exhaust manifold and two post-converter. Real OEM shows the Z3 has one 02 pre-cat and one 02 post cat. This is where you'll have issues if you're running an e36 mid pipe. If you look at the Z3 emission label it should tell you the number of 02's so you can verify what is shown on realoem.

You could, go to the junkyard and pull and emission label from a 328i and hope he doesn't verify the vin that's on the back of the cylinder head(if it's even there, its was on my m50) which he might not because he probably doesn't know its there. If he does and he looks it up in his system and sees that it's been smogged as a Z3 its whole life you might have issues.

Interesting, I didn't have to do this last time I went through BAR. Will have to look into it myself now too

[fastestbox]

BMW often assigns a different part number when a small detail changes. My bet is the Z3 M52 manifolds are a different part number because they come with M18x1.5 plug installed to seal off the O2 sensor bungs.


My '97 Z3 M52 manifolds look identical to the regular M52 manifolds and my Syncro Design Works downpipe fits up perfectly - it is just their regular part made for all M/S5x engines.


MJ

That's great news!! I gave up hoping that someone would chime in as it seems like Z3 information is limited. Thank you!

This means it'll fit like the e36 ones, which means I probably need to get some Treehouse style FCABs then?

[mjweimer]

BMW often assigns a different part number when a small detail changes. My bet is the Z3 M52 manifolds are a different part number because they come with M18x1.5 plug installed to seal off the O2 sensor bungs.


My '97 Z3 M52 manifolds look identical to the regular M52 manifolds and my Syncro Design Works downpipe fits up perfectly - it is just their regular part made for all M/S5x engines.


MJ

I guess I'll either learn it the hard way or find that it fits!

The engine mount arms are identical to an e36 and the front suspension seems to be exactly the same, so I don't see why the manifolds wouldn't be the same, yet they have different part numbers.

The Z3 M44 exhaust manifold is identical to the e30's, I know that has about zero correlation or weight but here's hoping!

I ended up chopping up the z3 harness in the process of getting the damn thing out (my first motor pull) so I ordered and received an e36 harness to eliminate some of the guess work.

[fastestbox]

no idea about exhaust, looks like you're gonna be the pioneer with that info. As far as engine harness goes, it's probably the same considering a z3 is considered an e36. You probably already have checked, but realoem probably has that info

I guess I'll either learn it the hard way or find that it fits!

The engine mount arms are identical to an e36 and the front suspension seems to be exactly the same, so I don't see why the manifolds wouldn't be the same, yet they have different part numbers.

The Z3 M44 exhaust manifold is identical to the e30's, I know that has about zero correlation or weight but here's hoping!

I ended up chopping up the z3 harness in the process of getting the damn thing out (my first motor pull) so I ordered and received an e36 harness to eliminate some of the guess work.

[wworm]

no idea about exhaust, looks like you're gonna be the pioneer with that info. As far as engine harness goes, it's probably the same considering a z3 is considered an e36. You probably already have checked, but realoem probably has that info

[fastestbox]

I know an OBD2 e36 has 4 oxygen sensors, one in each exhaust manifold and two post-converter. Real OEM shows the Z3 has one 02 pre-cat and one 02 post cat.

Good info! I'll save the sticker for sure. Now I'm just left with the question of if the Z3 manifold fits. The 2 O2s instead of 4 sound great to me, which means one cheaper cat instead of 2 if the OEM proves to be bad.
Plus I'm not sure how I'd have to change the harness if I wanted to run 4.


Last questions and I don't want to clutter everything with another thread but:

Does the Z3 exhaust manifold fit an E30? Does the midpipe? Can't find ANY info on this.

Is the Z3 engine harness a good candidate for splicing to the C101 or should I grab an E36 harness?


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[TheRob]

Even if, say I BAR it as an e36 swap rather than a Z3 for purely exhaust fit reasons?


Well, the thing is, they're going to ask for proof it's a California emission certified engine its a very recent rule that's been put into place and honestly I can't say what the ref is going to do if you have e36 stuff under there. You could always call and ask a ref, they're very helpful. I know an OBD2 e36 has 4 oxygen sensors, one in each exhaust manifold and two post-converter. Real OEM shows the Z3 has one 02 pre-cat and one 02 post cat. This is where you'll have issues if you're running an e36 mid pipe. If you look at the Z3 emission label it should tell you the number of 02's so you can verify what is shown on realoem.

You could, go to the junkyard and pull and emission label from a 328i and hope he doesn't verify the vin that's on the back of the cylinder head(if it's even there, its was on my m50) which he might not because he probably doesn't know its there. If he does and he looks it up in his system and sees that it's been smogged as a Z3 its whole life you might have issues.

[fastestbox]

Im pretty sure the entire exhaust until the cat is the same, highly doubt the Z3 got anything special there.

I found the manifold and mid section on RealOEM and it seems to be different than an e36. I've searched all over and I can't find anyone that has used the z3 manifold. The m42/m44 manifold on the e30 and the z3 are the same, and I know that's 2 less pipes to deal with but maybe it may mean the m52 z3 manifold will fit alright?

Treehouse racing CABs will help clear the downpipe, but you likely will need to "massage" the subframe, but many people have different ways of tackling this issue.

Have fun with that badboy. OBD1 intake, S50/S52 cams and a reflash and you're going to be happy as a clam

I'll have to pick up some of those CABs, will probably be able to sell my fresh poly garagistic offset lollipops to offset the cost.
And thank you! I'm super excited to finally have a car with torque again!

Keep the underhood emissions label for the Z3.

Even if, say I BAR it as an e36 swap rather than a Z3 for purely exhaust fit reasons?


Also another question! The z3 I bought has some backfees and I would like to junk it without having to deal with registering it or whatever. My local Pick N Pull seems to not buy cars unless they're under my name. Anyone have any insight? Should I just trailer it to a scrap yard or what? A surefire way to waive the fees and telling them I'm literally going to scrap it ASAP?

[TheRob]

My exhaust is almost entirely E36. If you have a welder, a chop saw and you'll need to get some exhaust piping of the right diameter it can be done. It tucks up nicely under the car and doesn't rub on anything. The mid pipe and cat are untouched of course

[KIRIEIW]

Z3 M52 in 1991 318is (California BAR)

Bolting a e36 exhaust to a e30 is, well easier said then done. I personally couldn’t get it to work with my car and I have no clue how Dmitriy got his bolted up for BAR. 100% will need to get a BFH at the bare minimum/ start forcing crap to fit. More then likely remove the entire front sway bar from the car. Not going to be easy that’s forsure.


Edit: Of course re install the sway bar after its BAR’d.



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[TheRob]

Keep the underhood emissions label for the Z3. The BAR wants to know the engine was from a California certified car and not a federally certified car. It will make everything easier. I didn't have that info when I had my first appointment and it took a little leg work to get the info.

[2mAn]

Wasnt that the same car I was looking at too? Sounds familiar.

Im pretty sure the entire exhaust until the cat is the same, highly doubt the Z3 got anything special there.

Treehouse racing CABs will help clear the downpipe, but you likely will need to "massage" the subframe, but many people have different ways of tackling this issue.

If you're going OBD2 dont forget to get every piece of the SAI. Search ... "MrGreen" (I think thats his name) he did a OBD2 M52 conversion here in SoCal and got it OBD2 legal

Have fun with that badboy. OBD1 intake, S50/S52 cams and a reflash and you're going to be happy as a clam

[wworm]

Funny that we were looking at the same car! Just out of curiousity, it's the one that's been epoxied and painted green right? I got to the PO's house and I was greeted by big metal teeth on the front of it - something that wasn't in the original craigslist post but funny nonetheless! (I'll post a pic of it tomorrow)

My car is already pretty low so I'm not thrilled about that, maybe the z3 one might fit a little better. Definitely going to need some custom exhaust work done regardless.

Already got the offset bushings so I'm already one more step ahead than I thought! Edit: thought solid as in the bushing not the arm, don't have the treehouse style so gotta add that to the list :(

Thanks for your response btw, and you'll be the first person I'll talk to about offloading some of these 318is parts. :)

hahahah yes thats the one! and happy to help. This should be fun to follow. Good luck!