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Actually, both Boxster engines are equipped with VarioCam variable valve timing. VarioCam does precisely what its name implies. It varies the timing of the intake camshafts to optimize the performance at any engine speed and load. The camshaft angle is continuously varied by means of twin rotary valve vane adjusters. VarioCam kicks in at 4200 RPMs and peak torque is on tap from 4700 to 6000 RPM.

As well as enhancing power and torque, the system offers smoother running, better fuel economy and lower exhaust emissions. The engine management system identifies current engine requirements, then automatically and seamlessly signals adjustment of the valve timing to match.

The Cayman S and 911 have VarioCam Plus which combines variable valve timing with two-stage lift on the inlet side. The resulting benefits include greater power and torque at all engine speeds, as well as smoother running, better fuel economy and fewer exhaust emissions.

Essentially, the system creates two engines out of one, switching seamlessly between them as driver inputs change. All operations are controlled by the engine management system, which ensures rapid acceleration and smoother running.

The two-stage valve lift mechanism on the inlet side includes a series of electro-hydraulically switchable tappets. Each of the 12 tappets consists of two concentric lifters, which can be locked together by means of a pin at the request of the engine management system. When the tappets are locked, the outermost ring – which is driven by two large-profile cams – is in direct contact with the valve. When the pin is removed, the innermost lifter – operated by a smaller cam lobe – has sole influence over the amount of valve lift. The timing of each valve is controlled by means of an electro-hydraulic rotary vane adjuster at the head of each inlet camshaft.

To improve responsiveness when starting from cold, VarioCam Plus will raise the amount of lift and retard the valve timing. At medium revs and minimal load, the valve lift is lowered and timing advanced to help minimise fuel consumption and emissions.

To achieve maximum power and torque, the lift is raised and the timing advanced.