[Liquidpaper]

Fellow Track Rats,

My new differential just showed up at the shop today -- getting it installed Monday. Pics to follow along with a very detailed review regarding street and track impressions.

[Anderw]

cool! can't wait to see your review really thinking about getting one myself

[inktomi]

If you don't mind my asking.. about what is the installed price on a custom diff?

[Liquidpaper]

I don't know what installation cost is yet, but the differential itself was 3800. It was custom built though, so that factors into the price. I also raised my final drive ratio to 3.46 from the stock 3.08. If you wanted a quaife or a cheaper clutch type, you could get away with much cheaper.

[ketema]

Definitely interested in getting same. I messaged diffs online but no response. I look forward to your review from on track

[Liquidpaper]

Originally Posted by ketema

Definitely interested in getting same. I messaged diffs online but no response. I look forward to your review from in track

He's been really busy. Try calling and leaving a message.

[Liquidpaper]

It's here . . .

[Iceman51sn]

Originally Posted by Liquidpaper

It's here . . .

Can't wait to read your review!

[Liquidpaper]

Picture of the differential.

Also, for those of you thinking of doing this, removing the rear end on an M235i is . . . interesting. Most BMW's (even the F30) have a bolted differential (for the axels and driveshaft). However, the M235i has splines (I think they're mechanically superior, but EXTREMELY HARD to fiddle with/swap out differentials). Will probably be a few more days in the shop

[///Mobbin]

Originally Posted by Liquidpaper

Picture of the differential.

Also, for those of you thinking of doing this, removing the rear end on an M235i is . . . interesting. Most BMW's (even the F30) have a bolted differential (for the axels and driveshaft). However, the M235i has splines (I think they're mechanically superior, but EXTREMELY HARD to fiddle with/swap out differentials). Will probably be a few more days in the shop

Very cool, can't wait to hear your impressions, congrats on the new go fast part!

[rwalker]

yeah, my shop charged me 7 hours for the diff swap :-(

[Liquidpaper]

Originally Posted by rwalker

yeah, my shop charged me 7 hours for the diff swap :-(

What differential did you swap in?

[rwalker]

I run a Quaife

[Liquidpaper]

Originally Posted by rwalker

I run a Quaife

Cool. Who'd you buy from?

[rwalker]

Harold at hpashop

[Liquidpaper]

Called the shop. It'll be done today.

I'll probably have some fun with it tonight down the PCH (after traffic is gone) -- maybe some easy canyons. Don't want to make it too hairy -- that shit is hard (and dangerous) when its dark outside.

Just so you all know, the differential spec is as follows:

Diffsonline 3-Clutch Custom
REM Polished Gears
35/60 Ramps
100 ft/lbs preload (will probably settle closer to 80 ft/lbs)
3.46 final drive ratio

I'm very excited for (1) the extra corner stability and traction (that "dig in" feeling accelerating around corners) and (2) the drive ratio increase (12% torque increase through the power band from mechanical advantage). Should definitely liven the car up.

I am also very interested to see how it behaves going into corners with that 60 ramp lockup. It seems like a 60 degree ramp would be a subtle lockup (probably is), but I wouldn't mind a little push going into/out of corners -- car tends to oversteer just a tad right now.

[Béhème]

Originally Posted by Liquidpaper

Fellow Track Rats,

My new differential just showed up at the shop today -- getting it installed Monday. Pics to follow along with a very detailed review regarding street and track impressions.

I'm afraid the differences shall be unnoticeable on the street and so subtle on the track, except for slow speed corner exits if you had spinning before, that it would take a road racing professional to appreciate and analyse the differences.

[ketema]

Originally Posted by Bhme

I'm afraid the differences shall be unnoticeable on the street and so subtle on the track, except for slow speed corner exits if you had spinning before, that it would take a road racing professional to appreciate and analyse the differences.

I don't think you need to be a professional on track to notice. I'm not a professional but I track a lot and I notice damn near anything that is changed or different with the car. I'm sure OP will be able to appreciate his purchase.

[Béhème]

Originally Posted by ketema

I don't think you need to be a professional on track to notice. I'm not a professional but I track a lot and I notice damn near anything that is changed or different with the car. I'm sure OP will be able to appreciate his purchase.

If your lap times are consistently within the same second, and very close to what a pro would do with the same car, I agree.

[Liquidpaper]

Originally Posted by Béhème

I'm afraid the differences shall be unnoticeable on the street and so subtle on the track, except for slow speed corner exits if you had spinning before, that it would take a road racing professional to appreciate and analyse the differences.

I might not notice the limited-slip functionality, but I will notice the 3.46 rear end immediately... lol

[ketema]

Originally Posted by Liquidpaper

I might not notice the limited-slip functionality, but I will notice the 3.46 rear end immediately... lol

Did you get one of those charts from diffs online that shows the maximum speed in each gear? How different is it from stock now? Definitely want to know if you feel like it accelerates faster. If you can get some timing data on a strip or track please post.

[Liquidpaper]

Originally Posted by ketema

Did you get one of those charts from diffs online that shows the maximum speed in each gear? How different is it from stock now? Definitely want to know if you feel like it accelerates faster. If you can get some timing data on a strip or track please post.

I did, and it's a significant boost -- about 12% increased torque from mechanical advantage at all RPMs.