M50 OBD1 -> S52 OBD2 swap requirements?

[cbr]

I've recently picked up an e30 with a M50 swapped into it and I'm trying to figure out what I'll need in terms of parts/etc to replace that motor with an S52 and convert to OBD2 at the same time.

From what I've found I think this is what I'm looking at needing:

- Engine (the oil pan is compatible, correct)?
- Wiring harness
- ECU
- Emissions crud (charcoal canister, evap, etc)

Is that it? It seems like an amazingly short parts list so I'm almost certain I'm missing a few key things...

(and apologies if this has been covered elsewhere)

[328ijunkie]

Don't need the emissions "crud"
Just get the ecu flashed...

[cbr]

Don't need the emissions "crud"
Just get the ecu flashed...

Unfortunately I'm in California and want to keep it street legal...

[328ijunkie]

We helped a member here "MrGreen" pass obd2 bar about a month ago.

[ian e30 318is]

We helped a member here "MrGreen" pass obd2 bar about a month ago.

Didn't know this was possible...I have been telling people the wrong thing for a couple months. How did you end up getting this to work? I was under the assumption that OBDI car needed OBDI engine and accessories.

[328ijunkie]

You have to keep the OBD whatever that came with engine.
M/s50=obd1 m/s52+=obd2

[4DR_Lou]

I'm currently doing an OBII m52 swap. from the top of my head, you will mainly need the following:

-OBII engine w/modified wiring harness
-e34 m50 oil pan w/modified dip stick tube (alternately, you can tap the oil pan for the drain)
-ECU w/deleted EWS (you can also keep EWS by wiring it up)
-modified water temp sensor (Markertmotorworks.com has these in stock)
-activated carbon canister
-fuel pressure sensor
-unmodified stock exhaust midpipe and catalytic converter
-smaller lower control arms to clear midpipe
-engine/trans mounts (i'm using Condor's kit)
-328i driveshaft (mated to a zf320 transmission)
-smaller brake boost to clear intake manifold (i'm using a modified Porsche 944 booster)

i may be missing a few things...

[cbr]

I'm currently doing an OBII m52 swap. from the top of my head, you will mainly need the following:

1. OBII engine w/modified wiring harness
2. e34 m50 oil pan w/modified dip stick tube (alternately, you can tap the oil pan for the drain)
3. ECU w/deleted EWS (you can also keep EWS by wiring it up)
4. modified water temp sensor (Markertmotorworks.com has these in stock)
5. activated carbon canister
6. fuel pressure sensor
7. unmodified stock exhaust midpipe and catalytic converter
8. smaller lower control arms to clear midpipe
9. engine/trans mounts (i'm using Condor's kit)
10. 328i driveshaft (mated to a zf320 transmission)
11. smaller brake boost to clear intake manifold (i'm using a modified Porsche 944 booster)

i may be missing a few things...

I renumbered your list for conciseness but I believe numbers 2, 4, 7, 8, 9, 10, and 11 would be identical from an M50 vs a S52/OBD-II build? Of particular concern on that list would be the lower control arms, if I don't have to touch those I'd rather avoid it...

[kronus]

there aren't any smaller control arms. I think he means smaller control arm bushings, like the Treehouse Racing ones.

4 is different, you need that one to connect to the OBD2 harness.

7 is different, the OBD2 midpipe has 2 O2 sensor bungs, 1 behind each cat. The OBD1 one just has 1. The part #s are also different, and a particularly anal referee will check.

the rest are the same.

[cbr]

Sweet! thanks!

[328ijunkie]

4 is the same, you need a retreaded sensor on a m/s52 no matter running obd1 or 2 (assuming early 97 and up Cyl head)

[4DR_Lou]

Kronus and Junkie are both correct. It's been awhile since I touched my unfinished swap. It looks like Treehouse's website is no longer available, but the CABs are alternatively obtainable from Vacmotorsports.

You will also need the air pump and the other components that attaches to the device:
http://www.realoem.com/bmw/enUS/show...diagId=11_1540


There are build threads out there for passing bar.. you just have to do research.
One member that comes to mind is Arch4angel.

[4DR_Lou]

Looks like Vac no longer sells them either

bimmerworld has CABs for sale also:

http://www.bimmerworld.com/Suspension-Steering/Control-Arm-Bushings/BimmerWorld-TrackCAB-Solid-Control-Arm-Mounts.html

Please note: If you look into Arch's thread, he had to shave a few from the smaller sized passenger side CAB to clear the midpipe. Correct me if I am wrong, you can bend the midpipe a bit to clear the midpipe... but in the end, it all depends on the ref you get during inspection.

[kronus]

I asked my ref (after I passed) about how much modification of the downpipe is allowed (including bending or denting) and he said that if he can see any, he has to fail it. so, uh, don't go to that ref, I guess.

FWIW I had a good amount of clearance with stock OBD1 downpipes and THR knockoffs. (you can get them on ebay) The OBD2 pipes are bigger due to external heatshielding, but not quite that much bigger. maybe a 1/4" more diameter?

[kronus]

4 is the same, you need a retreaded sensor on a m/s52 no matter running obd1 or 2 (assuming early 97 and up Cyl head)

on OBD1 harnesses there are two 2-pin plugs for the two water temp sensors. on OBD2, there is one 4-pin plug that goes to a combination sensor. because you'll need a e30 cluster temp sensor to have a reasonable water temp output, you need a harness that merges the two sensors into one plug.

so, yes, the sensor is the same, but you'll need to do some harness fuckery.

edit: you'll need to make basically the reverse of this harness