Diff options/opinions for swap

[PiercedE30]

I'm (going to be) running a 4.10LSD with a G260. I think my top speed in 5th is something like 156. I'm not going to be going that fast unless I'm at a racetrack.

[Beau B]

If you want a 3.15 you need to get one out of an M Roadster I ran that with my ZF S50 when I had it, basically if you are going to use the tranny out of the E36 m3 you want a gear ratio similar to that usually 3.15-3.46 and if you use the 260 you want one similar to your stock ratio 3.73-4.10 etc..

[bmwpower]

If you want a 3.15 you need to get one out of an M Roadster I ran that with my ZF S50 when I had it, basically if you are going to use the tranny out of the E36 m3 you want a gear ratio similar to that usually 3.15-3.46 and if you use the 260 you want one similar to your stock ratio 3.73-4.10 etc..

Thanks for the info. Not dying to use the 3.15, just may have had a line on a 3.15 cheap...oh well.

I'll look for the other rears, thanks.

[Van Westervelt]

I have s50 with the 260, running a 3.73 lsd. 75 mph in 5th gear and I am about 3k rpms.

I like it. First is a lil short but not ridiculous like with the 4.10. Car LOVES 3rd gear :)

[BeirBrennerE30]

th e36 m3 trans is a bolt in and requies less mods to work than an e30 trans. IMHO its the better option of the ones you listed. the diff ratio is really up to you based on how you use the car and the fuel ecomomy you want/ the acceleration you want.

[mazur]

I'm running a zf tranny with 3.73 diff. My top speed is 130mph at 7k rpm, lol.


3.25 would be nice.

I'm going turbo and think I'm going to go with a 2.95 rear end. Talk about cruising rpms

[Bmjpv]

My 3.25 lsd ??

First I had a 3.73 in my 88'is with the m20 motor,, In doing the 24v swap installed a 3.25 lsd !,, I installed a 95'zf M3 gear box ,,I'm turning 4k at 72mph ,, I'm running the 205/55/15 tire ! After reading this I think I don't have a 3.25 ,maybe what ?? I'll do the math ,,What did I install another 3;.73 ?? What ever I have it's not to good for these california freeways. !! joe

Well I did the math an I'm coming up with that 3.73 that I just got rid off !! I need to hear from other on the ratio issue ,,I was about to install a 2.93 lsd thinking that was my next swap !

[madjurgen]

a little too torquey for my taste

is that even possible?

[static]

is that even possible?

took words outta my mouf

yea more torque, but have to row the shifter more often

[Bmjpv]

I got 3.73s again ??

Ya ,the new (3.25 ?) went in at time of 24v install and ya the motors fun but I got tired real fast about not going fast ! If that's what happened,that I installed another 3.73lsd to replace my orginal 3.73lsd than that's about the dumpest BMW thing I've read about !! But it happened to ME !! I bought a 3.25lsd, but what do I get ?? someone else do the math and what do I have ? joe

[rede30]

there is a 3.46 option out there. I always forget about it myself, but i might try it out since my 3.25 is not as locky as it should be.

[Ablice]

I plan on starting with a 3.25LSD with my planned M50 swap. At 65mph/108kph that tach will be at 2500rpm. I liked the 2000rpm of the 2.79 eta :(

I'm thinking about a 2.93 or something, I want something tall geared (I'm using a Getrag 260) for fuel economy. Can the M50 pull a 2.79 or 2.93?

[Bmjpv]

Got the 3.73 again?

Ok ,I've got this done now,Installed a 2.93lsd in my 24v ,zf gear boxed 88'325is.. Yes the 3.25 lsd that I bought for my 24v swap to replace my stock 88' 325is (3.73lsd) turned out to be Another 3.73 and not the 3.25 that I wanted !! I installed yesterday a 2.93 lsd , I pulled the cover plate and counted teeth ,11-41 ,do the math and you get 3.73 again!! This 3.73 that I bought had 3.25 painted on the top and a tag for the 3.25 bolted to the cover ,Why wouldn't I beleave it's not a 3.25 ?? Anyway I like this gearing for driving ,nice change but I can Now see that the 3.25 could be a perfect gearing for 24v ZF gearboxes. FOR SALE NICE 3.73 lsd !! How dumb is all of that ?? joe

[e30polak]

a little too torquey = 3.46

is that even possible?

i like getting the extra traction off the line and the longer gears, second of all i live in LA so traffic on the 405 and the 10 suck balls with a short 1st and 2nd

[techmaniac]

Hi, I´m also starting this september my S50 swap, anyway... I was thinking in 4 diferent set ups for the tranny and diff, but havent found any usefull info... coments would be great...

1st:
E36 M3 trans with 4.1 diff = this should really give me some bad ass torque?? this would mean that at 100km/hr I would be around 4k rpms?

2nd
E30 G260 tranny with 4.1 diff = I dont know what would come out of this... any tips?

3rd:
E36 M3 trans with 3.25 diff = this would give me more economy than torque??? :S

4th:
E30 G260 trans with 3.25 diff = any coments about this one??

I care about high speed at low rpms, ending-speed, speedway confortability and a fun rear.... and I dont know how to get a little of everything...maybe another diff??

any tips are good tips...thanks