Borg-Warner has launched an electronically controlled four-wheel-drive system that is not engaged continuously but only as needed.
The system senses when a vehicle's front wheels slip and transfers power to the rear axle, from side-to-side or to a single wheel.
The InterActive Torque Management system was introduced on the Acura MDX, a luxury sport-utility that debuted in North America in September. A European application is expected in 2001.
The system consists of a housing, ring and pinion gear set; oil pump and associated bearings, seals and shafts; two InterActive Torque Management devices; and an electronic control unit. The system manages the torque between the front and rear axles and side-to-side across the rear axle.
The electronic basis of the system means that InterActive Torque Management is fully interactive with other vehicle systems such as antilock brakes and vehicle dynamic systems, allowing integration of four-wheel drive with other vehicle systems.
The system also provides additional traction for extreme off-road and towing applications, and allows better use of run-flat tires by allowing the drive system to cope with an unequal tire-rolling radius.
Its light weight improves fuel economy and reduces emissions compared with mechanical systems.