Porsche VarioCam

VarioCam was designed primarily to increase torque and power through the rev range, a good side effect is that it also helps to reduce hydrocarbon emissions to a high degree in the 968's exhaust.

The VarioCam operates between 1500 and 5500rpm, and will vary the timing of the inlet camshaft in relation to the exhaust camshaft this has the effect of increasing the overlap and so increases torque.

At the appropriate time the engine management system will send a command to the VarioCam solenoid to move a control piston, oil pressure will then flood a cylindrical chamber and this applies pressure onto the cam chain tensioner, varying the timing.

This system can adjust the cam timing by as much as 15deg., which enhances the torque by up to an extra 6lb ft. When 5500rpm is reached and more bhp is needed rather than torque the system goes into reverse, this can then release an extra 5bhp.