Most modern four wheel drive cars use a differential to control the distribution of engine torque between the front and the rear wheels. This centre differential has a significant impact on the handling of a 4WD car on different surfaces and individual drivers will have different preferences for how it is set up.

With the introduction of computer-controlled centre differentials and aftermarket electronics it is now possible to customise these handling characteristics. MoTeC supplies a range of centre differential controllers that can be configured to control the torque distribution by adjusting the percentage lock between front and rear differential.

Rally drivers and their teams can adjust the car's setup for various track surfaces and conditions and specific driver requirements. For example, reducing lock will improve turn-in, while increasing lock can promote understeer on both corner entry and exit and improve braking stability on loose surfaces. Naturally, the setup of the differential controller will also influence traction.

MoTeC's SDC (Subaru Diff Controller) and MDC (Mitsubishi Diff Controller) were designed with the current Group N favourites in mind; the 2003–2007 Subaru STi Impreza and the Mitsubishi Evo VII–X. The SDC and MDC units quickly and easily replace the factory centre differential controllers with no wiring modifications needed.

Models 

Currently there are centre differential controllers available for the following vehicles: