E30 diff upgrade

[Leonstt]

Hi guys

I have a question regarding diff ratio of my E30. The setup I'm running curently is M52B28 engine combined with E36 323i tranny and inthe back I'm using E30 M10 diff with 3.64:1 ratio. I'm not too happy with this Drivetrain setup because the gearing is way too short for my liking. What setup can I use to get longer gearing to make it a little more bearable on the highway? I have a budget, so i cannot go for some fancy racing diffs

Thanks

[82eye]

i think etas run 2:92.

[Northern]

https://www.e30zone.net/e30wiki/index.php/Differential

^ List of what cars came with which diffs.
You want something 2.93~3.25 to be close to stock. Which of these are actually available to you will depend on your country,

[82eye]

if you know what you are doing it is possible to swap gear sets in the case. the m10 would be a small case 168mm diff. something to keep in mind if you ultimately swap crown and pinion gear sets. not sure i would go to the bother unless the diff had an ls unit though.

[TobyB]

The small case can't go much lower- 3.45 from a manual E36 318's the practical limit. That case will bolt in, if you can find one from a 318ti

The mid case had 2.7x in early manual etas, 2.93 in later etas,
and the E36 can give you a 3.15 gearset if you
wanted to split the difference. but you'd have to assemble that, and make
sure you used a carrier from a 3.15 and higher e30, as the 2.93 carrier has different spacing.


t
2.93 and fine with that, because 1st is pretty low already.