Porsche Boxster - A powerful roadster with a powerful character
When revised last year, the entry-level Boxster was given new body colour air intake scoops at the side, a distinctly contoured “lip” at the front, a redesigned rear spoiler, a modified roof featuring a glass window for extra comfort and convenience, direction indicators in greyish-white at the rear, and two striking crossbars right at the end of the car. The most obvious difference between the Boxster and Boxster S – the former’s oval tailpipe as opposed to the latter’s twin tailpipes – has also been redesigned.
The entry-level Boxster, like the Boxster S, offers a high standard of performance and superior engine characteristics. Displacing 2.7-litres, the horizontally-opposed six-cylinder now develops its maximum output of 168kW (228bhp) at 6300rpm. Maximum torque of 260Nm (192bhp) in turn, comes at 4700rpm. With its standard five-speed manual gearbox, the Boxster accelerates from 0–100km/h in 6.4 seconds, some 0.2 seconds quicker than before. Top speed is 253km/h or 157mph. Despite this increase in power and performance fuel consumption is lower than before, returning 9.7 l/100 km (29.1 mpg) according to the EU standard (Tiptronic S: 10.7 l/100 km/26.4 mpg). This represents an improvement of approximately 2 per cent. As on the Boxster S, this is primarily attributable to VarioCam technology offering variable camshaft adjustment up to an angle of 40°, thereby reducing exhaust emissions and any loss of power in the charge cycle.
Valve timing on the intake camshafts is adjusted by a wing cell adjuster fitted directly on the camshafts in the sprocket drive wheel. Porsche was the first manufacturer to introduce this concept in the current 911 Carrera, oil pressure turning the position of the inner wing cell wheel versus the outer sprocket wheel by up to 40° crankshaft angle.
VarioCam is able to respond quickly and precisely to the driver’s demands, whether that be maximum power or a more reserved style of driving to cope with city traffic. This requires highly accurate valve timing both when opening and closing the valves, the intake camshaft being adjusted to an earlier intake point when running under part load. The higher amount of residual gas then remaining in the combustion chamber leads to a reduction in fuel consumption. Under full load, however, the engine builds up maximum power by reducing valve timing overlap on the intake and outlet sides to a minimum. Maximum torque, finally, is provided by large valve overlap with the intake valves closing at an earlier point.