S2.93 with 3 Disk Not Locking

[dsphil]

Hey guys, looking for some advice here. I recently installed the Thayer motorsports 3 disk clutch setup in my S2.93. After the first ~25 miles of easy driving and wide turns the breakaway torque was measured at abt 60ft/lbs at the right rear. After a few weeks, I did a hard 2nd gear pull and snapped a cheap rear cv (car is S50 powered) and coasted to a stop. Fast forward to my next track event at Palmer motorsports park and the cars is almost coming to a stop on the hard uphill left hander because its spinning the inside wheel so bad. I re-measured the breakaway torque and I can barely get my wrench to click at 40ft/lbs. Is there a chance my new friction disks are spent? Maybe the Belleville washer isn't preloading it enough? Any other thoughts? I did contact Theyer and the got back to me quickly saying that is seemed to be acting normal. I find this hard to believe since I recently drove an e36 M3 on the same track and just drove right through that same turn with no spin at all. Thanks in advance for any feedback.

40ft/lb is close to spec. I doubt there is any thing wrong with the unit if it is not making weird noises. An unequal limited slip will yield different results from a left and right turn. You can't compare to your e36 because you probably have different tires and suspension setups. To help with your wheel spin, try to loosen your rear sway bar. You really need to understand how it works on the road. It is important to keep both wheels in contact with the pavement and how to input power. Too much power will actually make the LSD less effective.

[Wanganstyle]

S2.93 with 3 Disk Not Locking

40ft/lb is close to spec. I doubt there is any thing wrong with the unit if it is not making weird noises. An unequal limited slip will yield different results from a left and right turn. You can't compare to your e36 because you probably have different tires and suspension setups. To help with your wheel spin, try to loosen your rear sway bar. You really need to understand how it works on the road. It is important to keep both wheels in contact with the pavement and how to input power. Too much power will actually make the LSD less effective.

A new Oem Lsd in a e30m or 325is will lock up and smoke 2 tires

The same 188mm zf 25% 2 plate Lsd is used in the e32 735i-5 speed manual and mine would do figure 8 doughnuts.

A the same unit was used in the e36m3 and if new or not worn out they will also do figure 8 doughnuts


On the track it’s a different story; the local track to benchmark with is Buttonwillow and the corner is club corner; if you are driving it correctly you’ll be flat out and the inside rear drive tire airborne. 2 plates will wheelspin, 3 plates will wheelspin, 4 plates if setup correctly will not.

This is data from actual testing on street legal 100-200tw tires with actual street cars and global time attack cars and nasa st4 cars.