S52 swap questions

[Poeman446]

First and foremost, i got a decent deal on a S52 and ZF 5 speed trans, complete harness, siemens ECM and a few other things, and I want to swap it into my e30. My main question is WHY do people convert it to OBD1 instead of leaving it OBD2? I can understand the intake manifold i guess, but even then, it seems like a lot of wasted time. I have all of the sensors on the engine, and I can get access to any that are not directly on the engine (i have full exhaust with O2 sensors, etc.) having that said, what other peripherals are needed for the OBD2 to work correctly? I planned on getting the EWS out of the car, but also having the ECM reflashed (is that possible/easily done on a siemens ECM?)


Next, I have an 1987 325is with the 3.73 LSD. Should i use the Getrag 260 that I already have and fab up all of my other brackets, or just use the ZF, and what all does that entail, such as rear differentials and other hardware. ( i can also buy the driveshaft) I know that the 3.73 will be geared too high for the ZF, so if i use it, then i need to get a new rear diff (probably from an eta). People who have used and do use the G260, do you recommend it or would you use the ZF? Thanks. I'm trying to do as much research as I can at the moment.

[justin_l_]

OBD1 used to be cheaper.

I used a ZF with a 3.23 out of an m coupe.
The only brackets you need to fab to run a 260 is the trans brace, which people on here sell all ready to go.

[pshooter]

I am also in the process of swapping an OBDII S52 w/ZF.
I know that the rear O2, SAP, EWS can all be flashed out.
I'd like to get to the essential number of sensors necessary to make a viable swap.
Using an M50 intake shouldn't pose too much of a problem adapting sensors.

Mine will primarily be a track / autocross car. That said I prefer not to trailer to my autoX events. Being an 87 in NY means they just look for a cat and no check engine light.

I'll leave the 3:73 for the time being. I'm sure I'll want taller gearing for WGI. But I'll see.

[Poeman446]

I believe there are similar laws in NC. they look to be sure there is no CEL and there are cats on the car, but I don't even know If i have to have cats on the car or not. I'm going to keep them just in case. I have a G260 that I bought out of a later model eta. probably has untold hundreds of thousands of miles on it. It came out of a junkyard car but the odometer was broken, I'm sure. Part of me wants to use the g260 because it will be a bit cheaper (I have no problem making my own brackets. I have access to a mill, lathe, welders and a little experience to get the job done too!), already have the driveshaft, etc. So it will save money. Similar story with the ZF, but I also want to use it because it matches the engine from the factory, however, the rear diff situation and driveshaft situation scares me away from it a little bit, as its sure to be a bit more expensive. I'm also worried about having annoying CELs, because if I put that kind of money in the car, I don't want it constantly throwing codes. Cheap, Fast, Reliable, choose two. I am choosing Reliable and Cheap(...Truthfully I don't mind spending a little money), and because its an S52 I'm leaving out 'fast', which is a relative term anyway. For someone like me, its fast enough for now.