Originally Posted by blue2000s
You can purchase torque biasing differentials like what's in your miata from guard transmissions or quaife. Guard also sells clutch lsds. 2009 is the first year that a mechanical limited slip is offered in the Cayman, I'm not sure about the Boxster.
Yes, LSD will be available on the 2009 Cayman and Boxster, but initially only with PDK and not a manual tranny. That is expected to change mid-year, but for now LSD with PDK only. As for a retrofit on a 986 and 987, I have seen threads regarding those that have added it, but someone that has actually had it done should comment, as I am not familiar with it.