Another start to an m50 build.

[brian90]

Hey R3V I am about to tackle the task of the popular m50 build. I currently have a 91 318is that has about 145000 miles on it. I'm trying to get this swap done as fast as possible because my car is hurting. I have a blown head gasket so I have mixed coolent and oil and it's plugging everything up in my car witch is making it over heat. I don't want to waste my money on trying to fix it because i have an m50b25tu sitting in my garage waiting to go in. I plan on having this done ASAP within 2 weeks. the engine I got is out of a 94 325i but the engine harness it came with is all chopped up. So after searching I found a guy that is selling a e34 525 that is a 95. Will this harness and even the ecu work in my car or even with my engine.I know in 95 they switched to obd2 so do i have to delete something from the harness or ecu because I don't want to run obd2. I have done quit a bit of research on the whole m50 swap (good waste of time in school) but I do still have questions. Everyones help will be greatly appreciated.

[748Snowman]

http://www.e30dohc.com/wiki/index.ph...HC_Swap_Basics


This is a good start if you haven't seen it before, other wise check the Stickies at the top of this forum.

[matt]

Yes, the harness and ECU will work out of the 5 series.

You need to pay attention to how you put the car together. The stock chip you will have is for a stock OBD1 3" MAF and green-top 17lb injectors. The M52 comes with an OBD2 MAF (sell it to someone) and pink top 21.5lb injectors. If you are going to run the M52 on the stock chip, use the green injectors. If you would prefer a tune for your actual motor, shoot me an email or PM and I'll be happy to sell you a chip for the M52 with pink injectors.

Thanks,
Matt
matt at racersmarket.net

[brian90]

Thanks for the input but I don't know if I'm just not reading it right or what. So when I use the OBD2 stuff on my 94 engine I will have to get a different MAF and Injectors or can I use what I have. Also do I have to bypass anything on the harness so I don't get fault codes? Lastly I was about to order the engine mounts from Bavauto but I noticed that there are two different models. Both are for the 535i but have two different production dates. Here are the part #'s what one should I buy? (#11 81 1 175 735, #11 81 1 132 793) Lastly I know what I have read but I want to make sure will the e32 brake booster and master work on my car with out any cutting of the firewall. I have seen a lot of people that say yes but no one really say about any custom work. Thanks guys I will keep this thread going with pictures of the progress here soon.

[matt]

Oh, sorry... you don't have any OBD2 stuff. I misread your post, thought it said M52 instead of M50TU. You shouldn't have to bypass anything, just use the computer and harness from the 5 series on your car and you'll be good to go. Stock OBD1 chip, MAF, and injectors.

[brian90]

Sweet thanks for your help matt. I know everyone gets all upset when someone says that they need to do it cheap but I'm in a tight situation and I need to get it done fast and cheap.I was reading about using the stock 240 tranny but I was not able to find what linkage to use. Do I need to use the 260 linkage but shorten it or what? Where can I find the connectors to make the harness adapter?

[JGood]

OBD-II started in 96. As Matt said, just swap the parts over from the 95, everything will connect right up. You can use the oil pan off the 95 as well, if you don't already have an e34 oil pan. It may even be easier to just pull the engine from the 95 and use it, if it's good.

As for the connectors, if you want to do it quick/easy, there are members of this and other forums that make complete plug and play adapters fairly cheaply. Or you can make your own adapter from connectors, just check junkyards or ask people who are parting out cars.

[brian90]

Yeah the engine i have is just rebuilt and the 5 series has over 200 thousand miles on it so i am going to use my engine. oh yeah blonde moment about obd2 i want to make my own adapter but i don't know where to get the connectors are they just the tops of the engine harness.

[matt]

You can cut the connector off your original motor harness and solder/crimp/connect it onto your new motor harness.

There are plenty of wiring diagrams around, or you can get a harness adapter.

[brian90]

oh sweet okay now i understand. that makes it a lot easier to grasp. Does anyone have ideas about the linkage or the booster. I keep reading the e32 is the same as the ix but i wanna make sure before i order it.

[lifeiskaos]

Best would be to get the linkage and carrier from a euro 320i. They had m20's with getrag 240's. The selector rod was $19 from the dealer, but I'm using a DTM style carrier bolted to the chassis, and don't know how much the carrier would cost. Also, if using a getrag 240, you'll want an e36 manual driveshaft with an e30 csb mounted backwards, or again, a euro 320i driveshaft.

735i and 325ix boosters are indeed the same, but you'll want to replace the pedal pickup fork from the e32 booster with an e30 fork.

[brian90]

Thanks for the clarification on this guys really. I'm going to order everything today then. Is there a reason why I can't used my center support bearing for the e36 driveshaft.

[brian90]

So I started to pull parts today off of the 95 525i. When I went and pulled the ecu it is a silver label 413. I know people were saying that's bad for the m50 swap. Why is that, and should I get my money back and try and find another ecu. What would be better to do because I hear that you just need to run a chip in it or something? Some input would be nice on this, thanks.

[matt]

There is no real difference between silver and red label ECUs. The only difference is the chip. The silver label ECU may have an EWS chip which will not run if you install it in an e30. If you get an EWS delete chip, or a performance chip, you will be fine with the silver label ECU.

[brian90]

Matt what would you recommend for a chip? I'm going to run everything stock but probably a custom exhaust and intake for now.