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M50/S50/S52 E30 Conversion

Discussion in 'E30 (1984-1993)' started by MGarrison, Jan 14, 2009.

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    mooseheadm5

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    ^----Exactly.

    I just wanted to put the idea into your head that you still don't have all the parts you need. You should get (should have gotten) the exhaust, PS pump, MAF, intake boot, rack (not necessary but a nice upgrade), radiator/hoses/tank, etc. Some people have tried E32/34 V8 boosters, but I never found out if they worked.
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    az3579

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    Whoa dude, I never said I had all the parts. It's probably going to be a looooooooooooooooooong while before I do. I expect to have all the parts by the winter, but if nothing comes up and everything goes according to plan financially, I might have all the parts by the end of summer. I'm saving up a bit so I could order more parts at a time, unless I come across a mega deal that has to be bought immediately.

    Why do y'all think I'm rushing into this? I'm taking my sweet old time.

    z31maniac guest

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    I don't care about how fast you buy you're parts.

    I'm talking about these very, VERY basic questions, have been answered dozens upon dozens of times.

    So I was telling you to quit being lazy and do some research. You need to go spend a week reading the 24v DOHC swap forum on www.r3vlimited.com.

    It will answer any possible question you might have without ever having to start a new thread. People who have done this swap (and are in the process) had to do the research, so everyone who is thinking about it needs to as well.

    Don't be lazy.
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    az3579

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    Read back a half a page or so. Paul asked me what parts I'm getting and I answered. I didn't go straight upfront and ask "what should I get?". I will do the research for the appropriate parts when the time comes to buy them. I didn't just basically ask up front what I need for the swap, I just answered Paul and perhaps asked a question or two in the process. It's not like I'm asking people to outline the swap on here. I know that section of r3v exists and will research it when the time comes, so there's no need to snap at me, thank-you-very-much.

    z31maniac guest

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    Now don't go getting all excited on me.

    [IMG]

    Autohaus guest

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    Yeah B, don't be lazy :). Will the euro bumpers come before S50?
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    az3579

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    Yes, because my OCD dicates that a straight bumper > S50 ANY DAY.
    Besides, I can't stand the rattle of the darned thing in the shock "socket" any more.
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    MGarrison

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    Duct-Tape uber alles! Or... ummm... yeah, that's it... Super-Glue! :p
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    Brian A

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    I completely disagree. The greatest of modern fix-anything automotive (and anything else) products is ShooGoo. My eyes get misty just thinking about the veritable plethora of issues that a small dab of ShooGoo has resolved.
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    az3579

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    So recent events has forced me to have to purchase an exhaust for my car.
    My problem: I don't want to spend money on an exhaust now and then have to spend money on it later for the S50 conversion.

    The swap is a long ways away, but I cannot live with such a loud muffler.

    Some background:
    Driving home one day from picking up a spare Euroweave for cheap, I hear a noise (windows down) rattling along the Merrit Parkway. I think nothing of it, thinking it was a car behind me, but when he got off the exit, the sound still existed. I also noticed my car was a bit louder than before.

    I pull off at the next service station and there is my hanging tailpipe, the end of it all shiny from dragging along behind me for 20 miles. The car sounds absolutely horrible, and is just a notch above the sound of those ricer Civics in the neighborhood. It is so loud that I can't have a conversation in the car with someone between 2000 and 28000rpm.

    I don't really want to get an exhaust "temporarily" just until I get the swap done; I want to put in the exhaust I will be using later, to save money. I have researched some forums on this (with the little free time I have nowadays, despite being off for 5 days in a row) and have found most people singing the "custom exhaust" tune. This sounds OK to me, as the local muffler place says it's cheaper for them to do a custom job than a stock one. Strange enough, but I don't mind the custom job being cheaper.

    Then someone offered to help me weld the new exhaust in place, which will save in labor (thanks Ben :) ), so all I have to do is order the correct exhaust now. I had my mech look at it and he says that everything from the cat back is all rusted, and there are multiple leaks throughout that section. I personally inspected the cat forward and it looked decent from there (no major rust, just a very very light coat of what looks like it), but from the back it looked as though it would all crumble apart.

    I found a used exhaust for a 325e somewhat locally. I read that this will choke the S50 in the higher rpm ranges, which I find logical. Another possibility was to get a 325i exhaust, but there are concerns that it might not be compatible with the exhaust manifold of the current M20B27. Is this the same exhaust manifold as the B25 or are they different? Any recommendations, without going the custom route (plug-and-play)? Or, is custom completely worth it, and would be compatible with my current setup AND the S50?

    I don't know if I have a correct view of the situation. If I was to change everything from the cat back (resonator and muffler and pipes), would that later bolt right on to an exhaust from the M3? I'm assuming I'm going to need the M3 headers or exhaust manifold (what's the difference between headers and exhaust manifold?) and a catalytic converter from it as well. Is this true?




    Seeing as this is the first time I've ever been involved with an exhaust, I'm learning little by little what each component does and how it fits into the picture. I'm just looking for opinions from some of you. So, any takers?

    (And before y'all flame me, yes I did look on r3v and still have some unanswered questions. Heck, I'm currently reading a thread on it and posting at the same time!)
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    mooseheadm5

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    The manifolds are the same. You can't use a cat-back 325i exhaust because your 325e has a single outlet cat and the 325i is dual. I have a spare 325i exhaust you can have really cheap, but it is pretty far from you. PM me with the closest greyhound station and I'll find out the shipping cost. Many S50 swappers use an E30 M3 exhaust, but that is not compatible with your current setup. Hell, think I saw one use an S50 exhaust with minor mods, but once again that would not work with your current setup. My advice would be used 325e or i exhaust and change it later. Custom is cheaper because they only pay for materials vs. the high price of the aftermarket Ansa or similar. You will have to do some exhaust work twice, so save the custom part for when the new motor goes in.
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    az3579

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    Ah, that was missing information. So, there are cats that have two outlets? Didn't know that; I thought that there is a single outlet and it splits into two or something.


    So what you're saying is that there is no exhaust that is fully compatible with my M20 and the S50, and that either way I'll have to pay for it twice?

    That's a real bummer. I can't use the 325i exhaust you suggested because as you said, my cat doesn't support it, unless the exhaust you are offering has a cat and everything there on?
    If this is the case, then I might be interested in swapping (I always liked the two-exhaust pipe look anyway) since the headers are the same. This exhaust isn't compatible with the S50 then either? It is my understanding that regardless of the headers, all the pipes merge into one or two pipes that lead into the cat, and from there on it shouldn't matter what catback exhaust you have since it's the same setup. Isn't this correct? Is there a reason why the 325i exhaust won't work with it (if there is a reason other than being restrictive)?

    As far as doing custom work twice, which part requires custom work?


    I'm just trying to understand how exhausts fit together and am doing a bad job at it. lol
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    mooseheadm5

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    Correct. Nothing is a direct bolt up. Both 325i and M3 exhaust have been used successfully, but there is some work that must be done either way. E36 exhaust has been used with only minor mods, but it is in no way compatible with the M20, so using it would require custom work now, and then undoing of said work later.

    THe 325i cat is two pipes in, two pipes out. The S50 headers do not bolt directly up to the M20 cat at all. That is where the custom work comes in. If you have and want to use a 325i exhaust, then you have to make pipes that go from the S50 manifolds to the m20 cat. Other than that, there is no reason not to use a 325i M20 exhaust (well, you may lose maybe 2HP on the top end.)

    You would not have to do custom work twice, but you will absolutely have to do exhaust work twice. Once to repair the problem you have now and once when you install the S50. I suggest taking the cheapest possible route now and saving the money for quality work when the S50 goes in. I PM'd you about the exhaust I have. That would be direct bolt up to the car and cost very little for installation. If you can't find anything cheaper than that, let me know. You would then either be able to have that modified for the S50 install, or just source an E36 exhaust.

    z31maniac guest

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    I'd go ahead and just do a 2.5" single from the header back. Then when the new motor goes in all the muffler shop will have to do is make a Y-pipe to connect the new headers to the existing exhaust.

    cognoscenti guest

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    Yep, you're stuck with doing exhaust twice, but this time can be on the cheap.

    On a tangent: why S50? An OBD1-converted S52 is a significantly better choice! Don't tell me price is the object, either - the two swaps have become remarkably close in cost during the last 1.5 years.
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    az3579

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    I've yet to be convinced as there is no proof that it is significantly better, if much better at all. They're the same in my eyes.
    Besides, it takes less to convert the S50 to OBD-I cost-wise and labor-wise, because... well, it's already OBD-I!


    And, there weren't any S52's for sale locally-enough for me to bother anyway.

    z31maniac guest

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    15-20 whp and 15 torques isn't better at all? And not having to worry about the lifter issues? Either way it will still be better than what you have now.

    When I called around to the different salvages the price of the two were always within a few hundred bucks. ALthough you do add another layer of expense by needing to get all the necessary OBD-I parts, usually somewhere between $400-650 to get manifold, sensors, etc.

    I did get to drive an OBD-I S52 in an E30 (mine isn't done yet) last weekend, all I can say is WOW. It's fantastic.
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    az3579

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    According to specs, they have the same (except for torque, which is minimally up). Are you saying the S52 allows for more power to actually get to the rear wheels?


    And even if this is the case, it's not worth the extra expense to me. Besides, why does everyone care all of a sudden that I have an S50 instead of a 52? Who cares?? It's an S5x, which is good enough for me. :D
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    mooseheadm5

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    The stock S52 makes the same HP, but more torque. Once you convert it to OBD1, it is similar to increasing displacement on an S50, since it is 3.2L instead of 3.0L
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    az3579

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    A little update on the project.
    Last week I ordered the E34 525i oil pan. This week I have another $xxx to play with and need to order some other parts.
    Unfortunately, the oil pan is the only thing I'm 100% sure of. Everything else is a "one person got this, the other got that" sort of situation. Different people are using different motor mounts, different brake boosters, different transmissions/flywheels/clutches/starters, etc...

    I need the setup that is the MOST compatible, and requires the least amount of modification to get it to work. I've been reading up on this in this thread:
    http://www.r3vlimited.com/board/showthread.php?t=45442

    There are waaaaaaaay too many pages of side conversations (why won't this work, that work) and 60 or so pages is just rediculous. I've read through about 27 of them this week and still haven't found solid answers to what I should be using to get the most compatible fit.

    I'm about 90% sure that I need E28 M5 motor mounts. I'm only 90% on that because I talked to someone at work and he said that he and his friend used E36 motor mounts on the E30 M50 swap they did. Is the E28 M5 the most compatible fit? Will it require any modifications whatsoever?

    I'm also reading about the transmission/flywheel/starter setup. People are saying the M20 flywheel won't quite sit flush with the oil pan. I have no idea how this whole transmission system works, or why a flywheel would come into contact with the oil pan, but I did plan on re-using the Getrag 260 if possible (because of price), but I might reconsider if it's "easier" to just use the E36 tranny. If I reuse the G260, then I think I'd need a custom transmission crossmember (what the heck is crossmember?). If I get an E36 tranny, this wouldn't be the case, but then I think I'd need a new driveshaft as well, and the shifter would have to be bent as well as it wouldn't sit quite right. If I got an E36 tranny with a matching driveshaft, would there be any extra work involved regarding custom fabrication or rebalancing?

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