A PORSCHE under-powered? Could it be true? Well, some people thought so when the original Boxster was unveilled back in 1996.

While its price-cut compared to the legendary 911 allowed a whole new income group to gain admittance to the very exclusive Porsche owners' club, its 2.5-litre "boxer" engine was regarded as being underwhelming.

Mind you, that's by Porsche standards, as a combination of 150kW and 245Nm wrapped in a sleek two-seat convertible body weighing in at 1250kg would more than satisfy most people.

But Porsche takes its reputation as a performance leader seriously. Hence the Boxster's capacity was boosted to 2.7 litres for 1999.

But that was not all. Enter the Boxster S - the ultimate Boxster.

At its heart is a bored version of that six-cylinder engine, which like the other Boxsters sits amidships inside the rear axle line. Capacity is out to 3179cc, power to 185kW at 6250 rpm and torque to 252Nm at 4500rpm. Kerb weight is up only 45kg.

With a claimed 0-100km/h time of 5.9 seconds and 0-400 metres in just 14.2, we are talking junior supercar pace here.

Variably timed double overhead camshafts with four valves per cylinder are a standard part of Boxster engine kit, but the S is unique in having a two-stage resonance intake manifold which aids power delivery and flexibility.

Engine management is provided by the Motronic ME 7.2, rather than the 5.2 system used by the 2.5 Boxster. Taken from the 911 Carerra 4, 7.2 allows the use of an electronic accelerator pedal, known as E-Gas.

The big advantage here is electronic management of the air flowing into the engine through the entire load range, which Porsche claims has a number of benefits in terms of driveability and smoothness.

Speaking of which, a six-speed manual gearbox - another donation from the Carrera - takes the place of the base mode's five-speeder as the standard gearbox, while the five-speed "Tiptonic S" semi-auto is an option. This gearbox includes a new toggle switch on the steering wheel to allow manual changing even if the gear lever is still in "D".

The chassis and suspension have also come in for attention.

The reinforced lightweight steel body is lowered 10mm and there are firmer shock absorbers, springs and stabiliser bars all-round, while the rear suspension features longer rear axle control arms to increase toe-in stiffness.

Other changes include revised wheel mounts, larger wheel bearings and larger wheels.

Unique design five-spoke, 17-inch wheels are standard all-round, seven inches wide up front and 8.5 inches wide at the rear. Pirelli P-Zeros are the tyre of choice, with the fronts measuring 205/50 ZR17 and the rears a meaty 255/40.

Completing the performance upgrade is a brake system that again owes its origins to the 911 Carrera. Compared to a 2.7 Boxster, brake disc diameter and width at both ends have been increased and the discs cross-drilled.

The aluminium four-piston calipers are painted red to differentiate them from the units used on the 2.7.

Other cosmetic external touches include titanium-coloured air scoops at the front, a Boxster S logo on the bootlid and twin exhaust pipes.

Inside the cabin, it is familiar territory for any Boxster owner, the S distinguished by black soft-paint finished on all plastic parts and surfaces, aluminium touches on the lid and door openers, the shift lever trim and instrument surrounds, greyish-silver instrument dials and an inner liner for the powered folding roof.

Storage space is limited but that's typical of all two-seat sportscars.

On top of the standard equipment which all Boxsters get - air-conditioning, radio and single-slot CD player, alcantara/cloth interior, powered seat rake adjustment and fog lights - the S exclusively gets an alarm system, remote central locking, intermittent windscreen wipers, illuminated vanity mirrors and a three-spoke steering wheel complete with the Porsche logo in aluminium colour.

Safety equipment for all Boxsters includes four airbags and anti-lock brakes.

The windscreen is reinforced for the unlikely event of a rollover and rollbars sit behind both seats.

The excellent Porsche Stability Management system as previously seen on the Carrera 4, a pop-up wind break and a hard top are all options.

Disappointingly, considering this car costs well over $100,000, so is cruise control.

But disappointment is an emotion rarely linked with the Boxster S.

From the moment you sink down, down into a cockpit that is surprisingly adjustable and comfortable - the driver's seat adjusts for height as well as fore and aft while the steering adjusts for reach - for what looks like a squeeze from a distance, the sheer quality and solidity of the package strikes you.

The steering wheel with its dimpled sections at 10-to-2, the large tacho smack-bang in the centre of the three-dial display, the clean and functional centre console, the body-hugging seats. It's all quality, it's all well thought out and executed.

And it's tactile. The gearshift, for instance, seems to anticipate where you want to go. It's surprising though, that it has quite a long throw and a distinct two-stage feel, nowhere near the snappiness of Honda's S2000, for instance.

But there's no supercar heaviness about it or the clutch. It's a manual gearbox you could live with day in and day out, and the pedal positioning is perfect for heel and toeing.

But it is not all good news. The lack of a left-foot rest is an odd omission, the stalks feel cheap and the plastic rear window is not good enough when you consider Mazda's MX-5 has glass.

But with that engine sitting in behind your right ear there is no forgetting this car's ultimate purpose.

There's a lovely collection of mechanical noises from the valvetrain, the exhaust and the driveline which evolves into an inspiring snarl as the revs rise. And the temptation is to hear that basso snarl time and again, such is the smoothness and linearity of the engine's response.

The tacho races around the dial, with the meat between 4000rpm and 7000rpm, propelling you hard and fast at the next corner.

Arrive there at speed and those big brakes do a magnificent job. Pedal pressure needs to be quite heavy but there is never a hint of fade.

The steering is also solid and heavy, perhaps not as alive as what you would expect but unerring in its accuracy and unless really provoked into oversteer, consistently neutral when cornering. Grip levels are incredibly high: no wonder PSM is an option.

That old bain of drop-tops - scuttle shake - only rears its ugly head on the roughest of surfaces, serving more to emphasise how strong and stiffly set up the S is. Yet the ride is not bone-rattling: it's more than acceptable considering the wheelbase, tyre size and chassis application.

Roof down, the Boxster S is a lovely flowing car, a uniquely Porsche blend of menace and performance. And with the windows up and wind breaker in place, top-down motoring is a pleasure, wind just clipping the top of a six-footers's head.

You can hear the engine all the more clearly and the brakes squealing as the calipers bite hard into the discs.

Roof up, the looks are less convincing and rearward visibility can be a challenge - thankfully the mirrors are huge. But there is no doubting the roof's effectiveness at keeping noise and weather out.

There is no doubt this is the ultimate Boxster ... at least for now.

You see, there's a Boxster coupe under development now and supposed to hit the streets in 2002. Can't wait for that one!