by narlystarly » Fri Jul 06, 2007 4:28 pm
S15 Helical LSD
The S15 differential has gears that are cut in a fashion that when the car is turning the gears mesh together and transfer power to the tire with more traction. It does not lock like a clutch diff, but is very smooth. The best thing about a helical diff is that it practically never wears out. You can treat it the same as an open diff, change the oil regularly and it will outlast the car.
The S15 helical differential is probably the best diff for road racing applications. It is not recomended for drifting because it never actually locks. The differential can only multiply the torque it can apply at the side with low traction, so if one tire has very little traction (such as on ice or in the air) then the differential will act the same as an open differential.
That last line leads me to believe that it will act like an open diff when both wheels are jacked up too. So theoretically the diff should be sweet.
Hope this helps, info from a wiki book site.