m52 e30 swap Diff option

[Yayrea]

Hello R3v, due to my project e30 being a salvaged title i decided to venture away from the LS2 swap until i get a clean title dream e30. Ive decided to go with a m52 for now on this body. I have the m20 and getrag 260 pulled along with the driveshaft and S2.79 LSD. I was surprised to have a 2.79 LSD out of my 85 325e. I would love to have this m52 boosted, but its not a guarantee. I havent completely decided how deep into this project im willing to go. I got my 325e for $200 and have put a few hundred into it tryin to bring the m20 back to life and some minor body work. I will eventually have to upgrade some of the suspension and brakes but im not sure which ratio of differential i should go with for a m52 swap. Still havent decided on which transmission im going to run either. I could stick with my current 260 but think im leaning towards the zf.



Any input would be helpful. Been reading that most people like to stick to the 3's when it comes to diff ratio. This is supposed to be a track build non CA street legal.

[pazi88]

With that diff ratio the 320z zf is the right gearbox choise. Those are dirt cheap and can be acheived from many different bmw models.

[Wanganstyle]

m52 e30 swap Diff option

track inspired “build”?

Welded diff is best for Instagram posting.

If you have an actual track and actual lap
Time reference then that data would be critical

M52b28+Zfsg320 in NorCal and middle cal is best with a 3,91 with 7,000rpm limit; thunderhill east/west, buttonwillow

Laguna Seca and Sonoma you could go 4,10 but realistically it gets busy. 3,91 would be the best choice overall

Anyone suggesting for a slug ratio 2,79 for a m52 has just honestly never gone to the racetrack;

[philakamrbean]

I've got a 3.64 torsen to toss into mine. The 3.64 is the common gear the ITR guys are running, so why re-invent the wheel? BTW, my car is only dedicated to dodging cones and track duty. Going behind a zf320 and 3.2L M50. :D

[agent]

I've got a 3.64 torsen to toss into mine. The 3.64 is the common gear the ITR guys are running, so why re-invent the wheel? BTW, my car is only dedicated to dodging cones and track duty. Going behind a zf320 and 3.2L M50. :D

Then you don't want a Torsen.

[philakamrbean]

I've got a z3m diff in it for now, but clutches need to be rebuilt. The 3.64 diff cost me a whopping $109 at the junkyard the other week. I've never run a torSen, and if I don't like it I can rebuild the 3.15 or find another diff in the 3.46 to 3.64 range and make something work.

[Yayrea]

track inspired “build”?

Welded diff is best for Instagram posting.

If you have an actual track and actual lap
Time reference then that data would be critical

M52b28+Zfsg320 in NorCal and middle cal is best with a 3,91 with 7,000rpm limit; thunderhill east/west, buttonwillow

Laguna Seca and Sonoma you could go 4,10 but realistically it gets busy. 3,91 would be the best choice overall

Anyone suggesting for a slug ratio 2,79 for a m52 has just honestly never gone to the racetrack;

Dont have a lap time in mind.
Just picked up my m52b28 which came with the zf 5spd trans and harness and Siemens 41.1 DME. Looked hard for a long time and was patient enough to find the complete long block with accessories withe the iron block. Looking to do the s52 cams, camshaft, m50 manifold, would like to bore the block to the 86.4mm and make it a 3.2L then add a turbo (still a rookie in the turbo field, trying to educate myself right now for the right choice turbo). Currently looking for the 3.91 differential (quite pricey), wish my 2.79 was worth money haha.



Working on all new suspension, brakes, subframe reinforcement, new brake/fuel lines and other cosmetics. Gathering parts for the build as that goes on. Got to find a reasonable machine shop to do the boring if i decide to go that route. Will need all new gaskets and would like to upgrade the clutch and flywheel while the m52 and zf are out of the car.



Will i be ok running this with my standard 4 lug setup with new brakes and calibers and rotors or should i upgrade to the big brake setup?


Thanks
Alex