The Cavalier Turbo, and
its sister the Calibra Turbo, were fitted with Vauxhall's viscous
coupled 4WD system in order to maximise grip by sending the 204BHP
through all 4 wheels
The
standard power distribution in normal driving conditions is around
75:25. That is 75% to the front axle and 25% to the rear but this can
vary according to the road conditions upto as much as 100% to the
rear.
The
ratio of this power transmission to the rear wheels is dependant on the
differences in RPM between the front and the rear wheels and is
controlled by the viscous coupling in the transfer box.
If
the foot-brake is applied when the vehicle is moving at speeds in
excess of 16mph (25km/h), the drive to the rear wheels is disengaged
via an hydraulically controlled multiple disc clutch within the
transfer box. The 4 wheel drive is then re-engaged automatically when
the brakes are released. All
this is done in a split second with no driver interaction.