S50 Vs. S52

[Yeee30]

Well I'm picking up my S52 for a killer deal and got everything off S52E30's car minus his motor! Build thread shortly.

sweet.. welcome to the club. u'll enjoy it alot.

[SwiftE30]

Yeah, I mean people complain about them "not being real M motors" but you will not know the difference when it is in your little light e30. Well, maybe you would if you have driven an s50B32 or s38b36/38 powered e30 :)

Who complains about an s52/s50 swapped e30 not being real M motors? THats exactly what they are.... Or maybe im just misunderstanding what you're saying.

[Wh33lhop]

The US-spec S50/S52 are just bored/stroked M50/M52s with hotter cams. European E36 M3s got the "real" S50B30 and S50B32 which are similar to the S54 and nothing like the US-spec motors; they rev higher, are more responsive, have double Vanos and make a lot more power.

[SwiftE30]

The increase in stroke is beneficial in an S52 no matter what people say.

S52 is better and will make more power, but it's more expensive to swap because of the OBDII.

The conversion to OBDI is not hard. If you think you can complete the engine swap itself, then OBDI conversion will be nothing.

You're going to have to weigh the pro's and con's, but S52 will always be better in my book (in N/A form).

If he can source the whole 97 M3 then it should be no question to run s52 OBD2. Thats exactly what i am doing right now, and the thought of trying to convert to OBD1 just sounded like a headache. A non neaded headache especially when i have the whole car as well.

Cons of doing the s50: no tranny, no extra stuff with it, ie harness, ac, ps, ecu,
Pros; it is already OBD1

Pros of going s52 route: You ahve everything needed to do the swap. It is very easy to stay with OBD2 when swappin in an e30 when you have a whole car to source from. All you will need is someone to make you an adapter for the wiring harness. And there are plenty of guys on here that do it for quite cheap. gregslow318i on r3v will be doing mine for me shortly.

[Wh33lhop]

If he can source the whole 97 M3 then it should be no question to run s52 OBD2. Thats exactly what i am doing right now, and the thought of trying to convert to OBD1 just sounded like a headache. A non neaded headache especially when i have the whole car as well.

Cons of doing the s50: no tranny, no extra stuff with it, ie harness, ac, ps, ecu,
Pros; it is already OBD1

You can use the stock G260/G240 and the stock driveshaft with it. If you use the ZF out of the M3 you need to source a driveshaft from a different car; IIRC an automatic E36 M3 works but don't quote me on that. Having said that this is sort of a mute point (sic) since the S50 needs a rebuild.

Pros of going s52 route: You ahve everything needed to do the swap. It is very easy to stay with OBD2 when swappin in an e30 when you have a whole car to source from. All you will need is someone to make you an adapter for the wiring harness.

I don't know why more people don't do this themselves. It's really as simple as getting an X20 and a C101 and connecting the pigtails. You are right about staying OBD2 being cheaper, as long as you want to retain all of the extra O2 sensors and aren't planning on tuning it. Personally I'd prefer going the OBD1 route and getting it BAR'd as a '95 M3.

[SwiftE30]

Im not good with electrical and the guy thats going to be doing it is local so im not to worried about it if theres problems. I thought is was possible to delete the 2 extra O2 sensors? and what does "getting it BAR'd" mean? I have no problem saying its an s52 from a 97 M3.

[SwiftE30]

heres the explanation of what the adapter does from the guy that will be doing it

This adapter will a take the big mystery out of the wiring your 24v e30 swap. Since bmw changed its plug configuration and style between the e30 and e36 body stiles this leads to a big road block to the swap. But my adapter will allow for the following functions on your swap.
starting
alternator charge indicator
services indicator reset
oil level for your obc (if applicable)
fuel consumption indicator
coolant temperature
check engine light (if applicable)
abs system (if applicable)
tachometer
oil pressure light
fuel pump


the adapter also comes standard with a jumper harness for the oil level sender and abs power lead. So that when you get your adapter, it is a simple 6 step installation.

[Adrian_Visser]

Make sure that the adapter also is wired correctly for vehicle speed signal and O2 sensor heater relay power.
It is really very easy to do it yourself all you need to do is read the etm and write shit down especially if all you are doing is making a pigtail adapter all you need is to butt splice the right wires together.

Regardless of whether you think you are good with electrical or not it is really a very simple process and as long as you double check everything i.e. ring the harness out with a meter afterward you will have a hard time making any mistakes.

[Wh33lhop]

Yeah, all of those "functions" are enabled by connecting a single wire. I understand if you just don't trust yourself but it is really simple. The wiring diagrams of each car can be found online, for free, instructions for how to read them can be found easily in JGood's sticky thread in this section. On top of that, plenty of adapter pin assignments/connections have been posted online, in r3v and other sites. It really is simple as hell.

[87e30]

Is the guy greg? Because greg won't sell you an obd2 adapter, obd1 only.

[SwiftE30]

hmm you guys make is sound not so difficult. and yeah it was greg that was going to do it but now that i know he doesnt make OBD2 adapters i might as well just do it myself. Makes sense, the thought of the swap was daunting and after researching im comfortable with doing it, its the wiring now that seems daunting. i guess just more research.

[Adrian_Visser]

AFAIK from a two minute search the x20/c101 is almost the same with just a few wires for EWS added. That is the main difference between OBDI and II, well that and having 4 O2 sensors. The EWS and extra O2 sensors can be programmed out of the DME with a reflash now though.

If you have a whole donor car that you can get the key, antenna and transponder and whatever else you need for the EWSII to work from it is only like 5 more wires to hook up (unverified internet opinion).

(You should do a search and some reading on this too. Search OBDII wiring kamasutra)

[SwiftE30]

yeah i just found that and i've been going over it. And yes i do have the whole car w/ key and everything else. I bought a 97 M3 with low miles with a damaged front end for such a screamin deal. It also had the whole setup for the m50 manifold conversion so that was a plus. My swap was put on hld becuase i had to wait for a MAF which took forever.