MoTeC’s Subaru Diff Controllers (SDC, SDC2 and SDC3) are suitable
for Subaru WRX and STi vehicles. They are plug-in replacements for the factory
fitted Driver Controlled Centre Diff (DCCD) controller, fitting into the OEM
box that is bolted to the steering column underneath the dashboard.
It is worth considering the installation of a MoTeC M800
Plug-In ECU in addition to the SDC2 or SDC3 to take advantage of several
additional features. Using the RS232 serial communication link, all values from
sensors connected to the SDC2 or SDC3 can be logged in the M800 Plug-In ECU,
without having to duplicate any of the sensors.
Functionality:
The SDC units are used to adjust the torque split between
the front and rear differentials to achieve greater control over handling
characteristics such as traction, braking on loose surfaces, turn in response,
and understeer on both corner entry and exit.
The center differential is essentially a limited slip
differential with adjustable preload. The SDCs work by regulating solenoid
current, which is proportional to the preload. When no current is applied (0%
lock) the center differential operates as an 'open diff' with a mechanical
torque distribution of 65% rear and 35% front (60% and 40% in some vehicles).
With increasing current (increasing percentage lock) the preload increases,
requiring more torque difference between front and rear wheels before the center
differential will slip.
There are six selectable control modes: 0% lock, 100% lock
and four user-configurable modes. These modes can be selected using the DCCD
thumb wheel.
Connector:
- SDC - 1 x 40 pin connector fitting directly into the factory
wiring
- SDC2 and SDC3 -2 x 24 pin connectors fitting directly into the factory
wiring
Communications:
- SDC - 1 x CAN
- SDC2 and SDC3 - 1 x CAN and 1 x RS232
