I've seen mostly Quaife in the US, but John Cooper offers ATB. How is ATB compares to Quaife?

ATB LSD

Quaife

 

ATB = Automatic Torque Biasing

Quaife = Brand of ATB differential

 

>>ATB = Automatic Torque Biasing
>>
>>Quaife = Brand of ATB differential

Thanks for the clarification! Totally make sense.

I guess the one JC offers is their own brand. JC LSD does look different than Quaife.

 

I highly doubt JCW makes their own differential. Most likely, it is a Quaife of Torsen unit that they resell. There's a great article in Grassroots Motorsports magazine this month about the various types of differentials:

http://www.grmotorsports.com/

 

If you go to the Minimania DriveTerain section you'll see both of these...click on them and read the write ups (and look at the prices) and I think you'll go with the Quaife IF that is the kind you want...
On there, the First one you posted is actually more expensive than the Quaife...
They also have the Phantom (which I just ordered)

L