Want to do S52 swap

[cowmoo32]

I just became the proud owner of a 1987 325. This is going to be my fun/track/autox car and I'm wanting to swap out the M20 and replace it with (preferably) an OBD-II S52. This is the parts list I've come up with so far. I would greatly appreciate if anyone could help me shed some light on this project and add any parts that I'll need to get in order to do this.

• S52 engine
• S52 wire harness
• S52 ECU
• Transmission
  • Getrag: upgrade tranny mounts
  • ZF: E36 driveshaft, use E30 guibo
• Oil Pan
  • M50 oil pan
  • M50 dip stick
  • M50 sump
• E36 throttle cable

Also, I have heard that OBD-I is easier, but is OBD-II that much harder that it's not worth the work for the power? I'm going to be COMPLETELY stripping the car. The wiring is shot; the last time it was driven, smoke started coming from under the dash.

[erik325i]

• Oil Pan
  • M50 oil pan
  • M50 dip stick
  • M50 sump

To be specific you need the oilpan from an e34 M50.

Also, I have heard that OBD-I is easier, but is OBD-II that much harder that it's not worth the work for the power?

You have it backward. You accually gain power from swapping to OBDI.

-Erik

[cowmoo32]

Really? Wow. From what I'm finding though, both the S50 and S52 produce 240hp.

[erik325i]

Really? Wow. From what I'm finding though, both the S50 and S52 produce 240hp.

Yes, stock they both produce 240 hp.
When you convert the s52 to OBDI however, you gain power. It is 3.2L afterall, so it should naturally have more power than the 3L s50. It's all the OBDII crap that's holding it back.

-Erik

[cowmoo32]

Ohhh, I thought you meant use the S50 b/c it's OBDI. You're saying take the S52 and convert it to OBDI. That makes sense

[devonjordan]

Not to thread jack, but realistically how hard is this swap?

Other than the parts that are needed how much custom modification is needed, ie changing the motor mount positions, or things of that nature. Im pretty sure me and a very well technically inclined friend can do teh pulling dropping and wiring, is there much more than that?

/end thread Jack.

Do the S52-->OBD1 that would be SICK!!!

[WillisE30]

Not to thread jack, but realistically how hard is this swap?

Other than the parts that are needed how much custom modification is needed, ie changing the motor mount positions, or things of that nature. Im pretty sure me and a very well technically inclined friend can do teh pulling dropping and wiring, is there much more than that?

/end thread Jack.

Do the S52-->OBD1 that would be SICK!!!

Search, there's a number of threads on it.

[cowmoo32]

Not a thread jack at all, I was wondering the same thing, actually.

[e30polak]

it's actually pretty straight forward, u got the parts list down, the hardest mod will be clearing the exhaust, i opteds for a 6-1 turbo manifold as my header and it works great, also the e21 booster provides half as much brake assist as the normal 3251 booster, so i will be installing a vacuum reservoir, don't forget to get a chip that gets rid of the speed sensor and EWS, without EWS removed u wont be able to start the car...the results r amazing, while ur at it u might as well upgrade to a 540 hfm and 24 lb injectors and get the chip from turnermotorsports.com with all the goodies on it...have fun with it...don't put ur budget too low, it may surprise u a lil but its definitely worth it :up:

[cowmoo32]

EWS? I haven't heard about that. I do plan on swapping out the manifold, though. Hadn't thought about injectors, but I might as well do it while the engine is out. I had hoped to be able to pay for this in one summer's worth of work, but it's looking more like 2-3...

Ive added a few things to my list, and I think it's pretty complete now.

7. Engine mounts
...a. E36 arms
...b. E28 535i mounts
8. Transmission mounts
9. Drive shaft (if needed)
10. E30 325iX brake booster

[euroshark]

This thread really thould be in the 24v section, here: 24v DOHC section

You will find lots more help there than in the M30 swap section! Good luck