I have a 93 hicas 240sx with lsd.
Now what is a 2way/lsd/vlsd er well what is the difference.
I have posi on my pickup truck is the another way or saying 2way??
I know the difference between posi/lsd/open though.
Well:
VLSD = VISCOUS Limited Slip Differential
LSD = Limited Slip Differential.
What’s the difference? In a VLSD, the spinning action of one axle versus the other heats up the viscous fluid and locks both axles together. It’s the fluid that does the work. In a mechanical LSD, like your posi-traction unit, the diff uses a clutch pack inside to transfer power to the wheel that isn’t slipping. You may have heard of setups like the Detroit Locker, for example, which is used in Drag racing. When actuated, the diff locks together with teeth and completely locks the diff together, meaning you’ll get the LSD effect for launch.
A 1 way LSD only works on acceleration effects.
A 2 way LSD works during acceleration and deceleration effects to stabilize the car.
Now, I’m sure the guys here can give you more detail - I drive a FWD car myself and don’t have all that much experience with LSD’s, other than to say my Spec V has one. 
This has been covered in great detail before. In the same section.
Since i am such a nice guy here you are
http://www.n-e-c-c.com/forum/viewtopic.php?t=4192&highlight=cusco+kazz
Coolio, that’s what I needed.