E36 LS1 Final Drive

[HIDGolf]

Have you guys looked into what gearing you are going to use in the rear? I know of 3 gearing options for the E36 M3. 3.15, 3.23, and 3.38 all with 25% locking. Im worried that with the double overdrive of the T56 that 6th would be only for triple digit speeds. I havent done the gearing calculations yet to confirm my theory.

[GotCone?]

Re: E36 LS1 Final Drive

mods... please don't approve my previous pending post. I finally calculated the gears and a 3.15 will be worthless on the street, but would lend itself to working well w/ 275/35-15 Hoosiers

[GotCone?]

Re: E36 LS1 Final Drive

I know this is an O L D thread...

but If one were to daily drive a LS1/T56 equpied E36 on stock diameter tires w/ a 3.15 LSD how 'bad' would it really be?

The thought is that 275/35-15 on 15x10 for auto-x might work well, but street driving might suffer significantly.

I'm only considering this because I have a nice near fresh 3.15 LSD on the shelf in the garage with a extra pack in there for more locking that I'd really like to use w/o changing out the final drive. Plus it will make it's way under my E36 before I can get to the LS-1/T56 swap.

[Fair!]

Re: E36 LS1 Final Drive

sweetness! Do you plan to modify the LSD to stay more "locked?" Is the 325's only 25% locking like the M3's?

Matteucci has experience with modifying E36 diffs for more grab, yes. It involves a bit of machining and the addition of additional clutch plates, and I presume more preload...

[HIDGolf]

Re: E36 LS1 Final Drive

sweetness! Do you plan to modify the LSD to stay more "locked?" Is the 325's only 25% locking like the M3's?

[Fair!]

Re: E36 LS1 Final Drive

Yes, the 3.91 LSD is what we went with. Matteucci calculated the gearing choice based on:

• Rear tire diameter (285/35/1
• to reach 70 mph in 2nd gear
  +using the 2nd gear ratio for the T56 and
  +7000 rpm limit
• Choosing from the various BMW E36 rear gear set-ups

With a .75:1 5th gear and a .50:1 6th gear, highway cruising will still be perfect with that final gearing. Gotta love the T56 and it's two overdrives. Should still get 30 mpg!

[HIDGolf]

Re: E36 LS1 Final Drive

nevermind, I just found the 3.91 LSD from a 325 mentioned in the other thread.