Which diff should i use?

[Strickly German]

Wats up i got a e30 im puttin a s50 in complete motor trans i have the diff also but i was told to use a 3.25 ive been searching and looking for vids but can really get an answer. Im lookin to do good numbers on the highway bassically w/e she can push and im not looking to get launched on off the line.. i was told a 3.46 is good but not sure on wat it gives u off the line and in top gear.. and secondly why cant i use the 95 e36 m3 diff isnt it a 3.46 also?

[1990m3]

search youtube, there are a lot of swap car vids and the diffs are often listed in the description.

e36 m3 diffs have different moutning points and will not work in an e30.

[sharky]

3:25 is a good multi use ratio.

[russiane30]

get a 3.25 i bought one from BOBY and i love it on a highway u top out about 145 148 and i raced with my friends e36m3 he was in a 4th and i was in 5th and it looked like he was standing still. its verru torque

[rThor432]

and secondly why cant i use the 95 e36 m3 diff isnt it a 3.46 also?

Only the auto-magic cars had that diff. The diff wont physically mount in your car, but iirc you can swap the ring/pinion/carrier into an E30 case.

get a 3.25 i bought one from BOBY and i love it on a highway u top out about 145 148 and i raced with my friends e36m3 he was in a 4th and i was in 5th and it looked like he was standing still. its verru torque

What engine do you have? Did the car run into the great wall of aerodynamics at 145, or did you run out of revs?

[e30polak]

The 3.46 diff will be faster in every respect, but will have a lower top speed, rev higher on the highway, and cause you to shift earlier.

I used to have the 3.25 with my s52+ZF set-up, and it was a great ratio. However, the 3.46 made the car accelerate faster in each gear. I will never go back! :woowoo:

[russiane30]

What engine do you have? Did the car run into the great wall of aerodynamics at 145, or did you run out of revs?[/quote]


its an s52 and i ran out of revs

[Strickly German]

Well ive seen the 3.25 on youtube and looks like it gets about wat u guys say is there another diff that can pull 155 out of 5th n not b a slug in 1st

[Uber E30]

2.93... its equal to a 3.73 with a g260

[gobuffs]

Stock 95 M3 diff was 3.15 FYI. 96s had a 3.23. Autos had a 3.38. There is no E36 that I can think of that had a 3.46. In fact 3.46s are fairly rare. Like others have said the E36 diff won't work, but the internals are the same 188mm.

[rThor432]

is there another diff that can pull 155 out of 5th n not b a slug in 1st

Well, the 2.93 with the 260 isnt a slug in first either.. I might go out and take 1st-3rd gear video in a little bit. I just realized that I've got a camera that is capable of video.

[Stu]

2.93... its equal to a 3.73 with a g260

Pretty close, 3.73*.805 = 3:1

My old car with stock 195/65/14 would pull to 6800-6900 with a 260 and 3.73, very slight uphill. Would not pull to 7100. I'm sure it would've pulled to redline on flat ground.

Dads old car with a 1:1 gearbox and 3.46 would pull 7500 in 5th. It may have had a little more.

With an overdrive 'box, I'd use a 3.73 or 3.91 with a 2.8 or greater motor. With a short-stroke 2.5, I'd use a 3.91 or 4.10.

The 1:1 gearbox is a blast with a 3.45 but 5th gear is way high on the revs.

[e30Rob]

since we're on this subject, i as well am in the middle of an M50 swap out of a 92 325is (no-vanos) i am using the Getrag 250 tranny and driveshaft from the 325is...I had a deposit on a 3.25 from the Euro Depot and they sold it out from under me so i ended up going with a 3.73.....only thing they had left in an LSD.....will this setup be ok?

[jahnaboi]

The 3.46 diff will be faster in every respect, but will have a lower top speed, rev higher on the highway, and cause you to shift earlier.

I used to have the 3.25 with my s52+ZF set-up, and it was a great ratio. However, the 3.46 made the car accelerate faster in each gear. I will never go back! :woowoo:

When are we running!?

[e30s50dan]

does anyone have a "Master list" of what diff's came out of which cars year/model/manual or auto ..i can then go to the junkyards