But in a twist that might cause a shudder of consternation amongst aficionados, Porsche has also been working to make the GT3 more acceptable to a wider audience, fitting the hardcore 911 with traction and stability control systems, together with satnav and even the option of a top-end hi-fi.

The 3.6-litre flat-six's impressive hike in horsepower over the 321bhp of the standard 997 Carrera (not to mention the 375bhp of the previous GT3) is down to a sophisticated new variable intake manifold and sports exhaust, combined with lighter rotating masses (crankshaft, conrods, etc) that allow the engine to rev to 8400rpm. Porsche claims that the power output of the GT3, which equates to 114bhp per litre, is about the maximum you're likely to achieve with a road-homologated naturally aspirated engine. And if you're wondering why Porsche has stuck to a 3.6-litre capacity for the GT3 when the Carrera S has a 3.8-litre lump, it's to do with motorsport homologation requirements.

Sitting 10mm lower than even a sports chassis-equipped Carrera S, the new GT3 features suitably upgraded suspension components, yet these are all still governed by the PASM (Porsche Active Suspension Management) system that's standard on the Carrera S.

In addition to a mechanical limited-slip differential, the GT3 also has traction control derived from the Carrera GT supercar's. Its trigger-points are higher than in other 911s, and the threshold can be raised even further in 'sport' mode. Of course, there's also the option to switch the system off completely, for track work, say, although Porsche suggests that, even with it switched on, most drivers are unlikely to trigger it until the point that they actually need it.

Michelin has developed a version of its track-biased Pilot Sport Cup rubber specifically for the GT3. To improve tyre life, the compound is said to be harder than might normally be the case, yet it's still capable of far greater grip on dry and even 'moist' surfaces than standard tyres.

Brakes grow in diameter to 350mm all-round, with six-piston callipers on the front, four-pots at the back. For a further £5349 you can opt for ceramic-composite discs. The ABS threshold has also been raised from that of standard 911s.

In a quest to keep weight down, the GT3 does without underseal (though it is not completely without rustproofing) and sound insulation, and boasts a composite engine cover and (like the Turbo) aluminium doors. Kerb weight is listed as 1395kg - 15kg more than the outgoing model - although you can save a little more weight by opting for Carrera GT-derived carbonfibre seats that tip the scales at just 10kg each.

Those seats are essential, by the way, if you want to tick the box for the no-cost-option Clubsport package, which gets you six-point harnesses, a rear roll-cage, fire extinguisher and what's called a 'battery master switch preparation kit' (Porsche will charge you extra should you want the actual switch).

Porsche insists that the higher equipment levels of the new GT3 won't dilute its character or ability, merely give it more 'universal' appeal. However, in an unusual move for a company that seldom admits to any future model plans, Porsche has already confirmed that there will be a more hardcore GT3 RS 'coming soon'.