Like BMW, Audi will come with the torque vectoring transmission technology. This differential is able to distribute torque from the engine in continuously variable proportions between the rear wheels. It has superimposed stages at the left and right, and a multi-plate clutch running in an oil bath. The clutches are activated by an electro-hydraulic actuator.
The superimposed output stage rotates 10% faster than the half-shaft that normally drives the wheel; the two drivelines can be connected together by the multi-plate clutch. If the clutch is engaged by slippery, the wheel is accelerated and thus receives an additional torque input. The differential reduces the tractive force reaching the opposite wheel accordingly. In most driving situations, almost the complete input torque can be diverted to one rear wheel in this way. The maximum difference in torque between the wheels is 1,800 Nm.
The torque vectoring differential will be available from 2008 onwards.
Yvonnick Gazeau
