Clutch-type LSD questions

1 - Yes, 100% locking is both wheels locked solid and driving togethor. 50% would therefore be half of the drive torqie converted into locking force. This doesn't necessarily mean drive distribution as that is also a function of drive plate coefficients and preload.

2 - Initially it is more a fuction of preload than ramp angle. The preload is creating a static frction between the plates. Therefore, when you have no preload, you have abrupt locking changes from drive to coast whereas tighter preloads are gentler transitions. Beware, more preload is not a good thing as it creates inconsistent locking bias. The preload can create an excessive amount of locking initially, then be overcome by differential forces and fall off due to a lack of ramp angle, etc. I've only ever used enough reload to get the initial bite progressive. Any more creates problems and heat.

3 - In really low grip conditions you would want a fair bit of ramp angle with a moderate amount of preload.

4 - Friction modifiers are black magic and can be inconsistent in performance. Lubrizol 7906 was always good for clutch pack life but they are not a magic bullet to diff tuning. Most of the friction modifiers commercially available for clutch pack diffs were created to solve problems for car companies under warranty. Figuring out the mechanical fundamentals first is the better way.

 

Can anyone comment on why a 348 has no static preload in the clutch packs?