Torsen LSD or not? How to prove?
10-10-2006, 10:07 AM
#31
Rennlist Member
By turning the wheels with the car in the air, you are in effect checking/testing the unloaded lock, since the wheels are turning the drivetrain. If you want to check the loaded lock, you need to turn the driveshaft and check which direction the wheels turn (hard to do, unless you have the engine out of the car and can easily grab the drive shaft sticking out of the torque tube....).
For a clutch type LSD to have the rear wheels spin in opposite directions, I believe it would have to be setup so that it nearly 0% lock unloaded. Stock 944 LSDs are 40% loaded/ 40% unloaded lock, so the wheels will turn in the same direction regardless (either turning the drive shaft, or spinning a wheel). I dont know what the lock %'s are for a 993.
There are some clutch type LSDs that are setup for racing that have 0% unloaded lock - I believe this is done/preferred for guys that do a lot of trail braking (since I dont think you would want the rear wheels tied together when turning under braking). For those LSDs, turning the wheels by hand, they will spin in opposite directions, but if you turn the driveshaft, or trans input shaft, they spin in the same direction.
For a clutch type LSD to have the rear wheels spin in opposite directions, I believe it would have to be setup so that it nearly 0% lock unloaded. Stock 944 LSDs are 40% loaded/ 40% unloaded lock, so the wheels will turn in the same direction regardless (either turning the drive shaft, or spinning a wheel). I dont know what the lock %'s are for a 993.
There are some clutch type LSDs that are setup for racing that have 0% unloaded lock - I believe this is done/preferred for guys that do a lot of trail braking (since I dont think you would want the rear wheels tied together when turning under braking). For those LSDs, turning the wheels by hand, they will spin in opposite directions, but if you turn the driveshaft, or trans input shaft, they spin in the same direction.
