Diff options/opinions for swap

[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

[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.

[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 :)

[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.

[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..

[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.

[ericzz]

I am running an e36 trans . I did the swap with the 3:25 and after a few days went to a 3:46 and will not go back . I can cruise at 60 with a 3k rpm . I may have a tach that is not 100% but it's close! Go witht he 3:46 unless you spend 75% of the time on the highways


FYI I HAVE A 50,000 MILES LSD 3:25 FROM A 535IS FOR SALE .

[bmwpower]

it actually matters a lot... decide on your transmission first! then pick a complimentary rear end.

fun and good on highways are mutually exclusive when picking a diff... a 4.10 would be fun.... a 3.15 would be good on highways

Ok... so which is better to have....E36 M3 trans or E30 G260? Longevity wise, performance. With the G260 I need a custom bracket, with the M3 trans I won't...those kind of thing too.

Which trans provides the most & less expensive options when picking a rear? I don't want to go one way and find out I only have a couple of options and they're all $$$.

[BeirBrennerE30]

Ok, but does it matter which transmission?

I'm either going with an E30 G260 or the E36 M3 transmission.

I want a rear end that is fun, but is also good on highways.

it actually matters a lot... decide on your transmission first! then pick a complimentary rear end.

fun and good on highways are mutually exclusive when picking a diff... a 4.10 would be fun.... a 3.15 would be good on highways

[bmwpower]

3:46 is way fun
3:25 is great for spirited driving and daily use with highways .

Which trans are you using?

[matt]

Ok, but does it matter which transmission?

I'm either going with an E30 G260 or the E36 M3 transmission.

I want a rear end that is fun, but is also good on highways.

Of course it matters.

[bmwpower]

3:46 is way fun
3:25 is great for spirited driving and daily use with highways .

Ok, but does it matter which transmission?

I'm either going with an E30 G260 or the E36 M3 transmission.

I want a rear end that is fun, but is also good on highways.

[ericzz]

3:46 is way fun
3:25 is great for spirited driving and daily use with highways .

[e30polak]

i heard 3.46lsd is also fun, a little too torquey for my taste

[static]

i like my s50/ZF/3.25lsd combo for every day driving, on highway and in the city.