Even hotter Boxster on the cards

PORSCHE has plans for an even hotter version of its popular Boxster roadster than the new S model, which will debut in Australia later this year.

The planned car is said to be the true spiritual successor to the legendary 550 Spyder, which inspired the Boxster.

Approval for the high performance lightweight model is still some months away but prototypes are being tested in Germany with performance to match the 911 Carrera.

The prototypes are using a more developed version of the flat-six engine fitted to the Boxster S.

Porsche engineers have met their aim of generating about 75kW (100 horsepower) per litre, meaning the 3.2-litre engine produces about 240kW - putting it on a par with the upcoming 3.4-litre BMW M3 Coupe and supercharged V6 Mercedes-Benz SLK.

The Boxster S, which is slated for an Australian debut at the Sydney Motor Show in October, has 187kW and accelerates to 100km/h in 5.9 seconds.

But the planned lightweight model is said to achieve the same target in just 5.5 seconds.

An output of 75kW was once the domain of pure racing engines but now it is the goal for top-end sports cars like the Porsche 911 GT3.

"With the new GT3 we've achieved a specific output of 100bhp per litre," a Porsche insider told British Autocar magazine.

"There's no reason why that could not be applied to other variants of our water-cooled engine." Along with extra power, the improved performance will come from a weight reduction program.

As well as aluminium doors, bonnet and boot lid, the car reportedly features a 1950s-style low-cut windscreen and a sparse cabin with lightweight seat shells which convey a racing feel.

Porsche's fortunes around the world have been revived by the Boxster since its debut in 1996, providing a much needed new entry level model.

The car has been so successful the company held back the introduction of the bigger engined Boxster S for almost a year while it worked at reducing waiting lists around the world.

It has just been released overseas and will hit Australian showrooms in December.

The Boxster S raises the performance level for the first time with the standard 2.5-litre engine stretched to 3.2-litres, increasing power by 20 per cent and torque by 25 per cent.

That should satisfy those who believe the standard Boxster does not have quite enough power to make the most of the car's brilliant handling.

And as if the extra power, a higher red-line and more low-end punch are not enough to mark the Boxster S as a driver's car, it also gets a new six-speed gearbox to maximise the benefits.

The Boxster S rides on bigger wheels, has slightly firmer suspension to deal with the 45kg weight increase and features bigger brakes all round.

Porsche's five-speed Tiptronic automatic transmission - with manual shifting via steering wheel buttons - remains an option.

Apart from the S badges, the new car is identified only by an extra air intake in the nose and twin exhaust pipes at the back.