The oem vlsd will open up when hot. When fresh, I could do about 30 minutes on the track before it got hot. With wear and tear. I was down to 10 minutes before it would give up the ghost.
The Quaife, WaveTrac, TruTrac, and the new Z1 are gear driven. If you jack up one wheel. The Quaife will open up. The Wavetrac will not. Don't know about the Z1 unit. The TruTrac doesn't fit the Z. Plus side on these is that you can use regular gear lube.
Clutch type like OS Giken, Cusco etc are tunable. You can set them up 1 way, 1.5 way, and 2 way. Plus you can change the amount of lock up. I have an OS Giken set up 1.5 way and 80% lock. The down side is that you have to use gear lube with the LSD additive. The OS Giken needs it's own lube. 75w-280. Which is $70.00 a liter.
