AFAIK the Boxter does not have a limited slip, nor is it available as an option. However, if you have Porsche Stability Management (PSM) or its predecessor traction control system, it will have a similar effect to a LSD.
Traction control uses the ABS sensors to detect wheel slip (e.g., inside wheel in a corner)and lightly applies some braking to just that wheel. The open (non-LS) differential doesn't know the difference between the slipping wheel actually regaining traction or being dragged by the brake. In either case it will send more torque to the wheel that has traction, which is the desired effect and what a limited slip differential does.
I do not know what the equivalent "slip factor" for this type of traction control is, or even whether it's meaningful.
Linear Mode
