m30 4.10 diff?

[afelice]

I am looking to do a m30 swap soon and my car has a 4.10 limited slip and I was wondering if anyone else is running this set up and how they feel about it or if someone is running a 3.91 diff how they feel about that im just curious what peoples thoughts are on it

[LJ851]

Too much gear in my opinion. Somewhere around 3.5 ratio matches the m30 torque curve nicely.

[Alpina]

Too much gear in my opinion. Somewhere around 3.5 ratio matches the m30 torque curve nicely.

agreed.......

3,46 3.64

[uturn]

1st gear will be the dedicated donut burnout gear!

[E30SPDFRK]

I had a 4.10 on my last m30 swap like 6 years ago, it was fun but there was a lot of shifting involved. I had a 3.25 with my first m30 swap and I thought it was a bit too tall for the power, I agree that 3.46 or 3.64 would be the perfect ratios.

[MR 325]

A 4.10 and even a 3.73 are too short in my opinion.

I'd recommend 3.25 or 3.46.

[ethrty]

definately agree. 3.2x to 3.64

luckly you will have no trouble selling the 4.1

[ThatOneEuroE30]

As what others have stated or a 2.93 if your running a g265 cant say if its any different on a g240. Most turbo m30 guys will run a 2.93 ive noticed

[lukeADE335i]

The first 3 gears are longer on the G240 by between .1 to .2 vs. the G260 depending on the gear, so what ever diff you run, you'll have slightly longer gears on the gears that really matter for acceleration from a standing start (with 4th being 1:1 on both and 5th being 0.81 on both).

I've run 3.25, 3.46 and 3.73 gears in mine & driven a 3.9 LSD equipped M30 swap too. The 3.9 LSD is usable, but pretty short. I'd say the 4.10 is pushing it too far.

Depends what you want out of the car - smooth daily that has some grunt, but feels like what BMW would have done from the factory: 3.25 (I currently run a 3.25LSD).

Fun weekender that hammers, feels effortless in any gear, and likes to drink fuel: 3.73.

If you were to run a 3.9 diff, I'd run a hotter cam, beefed up rockers, a set of headers & extend the redline to 7000RPM. Then your torque curve would match the diff better :devil:

[CorvallisBMW]

Agreed, anything over 3.73 is too short.

[afelice]

thank you all so much for your help! I think im going to go with a 3.25lsd when I can id also like to turbo the car so I think it will be good for that

[CorvallisBMW]

I'm about to try a 2.93lsd in my turbo m30, I'll report back with notes :up:

[afelice]

Thanks!

[totheredline]

I'll be running a 3.73 on my fully built, carbed, m30 in what should be a 2,300lb car.

[Doughnut]

I had a 3.46 with my g265 it was awesome! 1st gear was quite short but suited my driving style.