Driven: Porsche 911 GT3 RS

The return of Porsche's homologation special means sleepless nights for Adam Towler

So here it is, the moment many of us have been waiting for: Porsche's homologation special returns, squeaking its way across the blindingly clean workshop floor of the Weissach Motorsport department and out into the wide world.

It is, according to its instigator Andreas Preuninger - head of the GT department at Porsche - a "car that a guy must see an advert for, and then not be able to sleep that night". I'd go along with that: the night before I drove it I couldn't sleep. It is also claimed to differentiate more from the standard GT3 than the Gen 1 version did (along with a seven seconds faster 'Ring time), but at £104,841 it is also £18,777 more expensive than a standard GT3, a car that, it should be remembered, is already sublime.

As with the previous 997 (Gen 1) RS, the new car uses the 44mm wider body from the Turbo/four-wheel drive Carrera models, but now teamed with extensions around the front wheels too, allowing Porsche to increase the front tyre contact patch.

Engine and chassis, weight-loss and aero: those are the three main areas of development. For the former, Porsche has carried over the new 3.8-litre motor from the regular GT3, but there are a few changes to take the power up to 450hp (from 435hp).

Chiefly, these involve a whole new air intake system breathing through two enlarged ram air intakes on the engine lid, the ECU is remapped, there's a modified titanium exhaust, and a further 1kg has been machined off the single-mass flywheel compared to the old car. Compared to the GT3 the dampers are new and the anti-roll bars revised, while PADM active engine mounts are standard fit, as is PASM suspension and full stability and traction control.

RS weight is quoted at 1,370kg (with full fluids), some 25kg less than a regular GT3 and around 80kg more than a GT3 Cup race car. However, to get to that figure you need to specify the carbon ceramic brake option and the lightweight seats, as well as leaving out air conditioning. The test car we drive is to this full lightweight spec, or as Preuninger says, "how we like it".

Porsche's problem is that for every kilo they save, others are being put back in. For starters, the wider body is heavier, there's the Clubsport cage, and the Gen 2 911s have more weight in the nose due to increased crash protection. In response, Porsche has the single nut lightweight wheels, a plastic rear 'screen, a composite engine cover and the carbon fibre rear wing. Then you factor in the carbon buckets, the ceramics, the optional lightweight battery (-10kg).

You can also leave out any form of stereo, as in this car (-4kg if its PCM3), and I would have suggested the deletion of xenon lights. But apparently the extra weight of these is pretty much all down to the extra fluid in the larger washer reservoir that legislation demands, and you need them for fast night driving according to the boss, so simply run them dry.

Porsche has also tried harder with the little details this time around: there is no sound deadening in the roof on the RS, there are no internal door handles (just red pull cords) and even the cup holders have been deleted from the dash (saving 300gms!).

Most obvious are the changes to the aerodynamics, with the addition of the Cup-style front splitter and the rear wing, closely related to that on the RSR and the new R. At full chat the new RS produces 170kg of downforce, or put another way, at 100mph it produces the same amount of downforce as the Gen 1 RS did flat out.

Today, on the tight mountain roads in southern France, that may not be so important. All of the above tech talk is great, but the thing that really grabs you by the undercarriage is the feel and emotion of this car. It's just so responsive, so precise and analogue, so pure in feel. That sound too - reverberating off the mountainside from over a mile away - exotic, granite-edged and rising to a pitch and volume where it seems the engine must burst apart.

The moment you fire it up the noise drills into the cockpit, the flywheel clattering away like an old taxi idling. The alcantara wheel and gear knob feel just right in the hands, with the former connected to an outstanding steering system full of feel and of ideal weighting: the latter, like the regular GT3, has a really sturdy, mechanical mechanism that comes into its own when you're changing gear at high revs. It's not the most relaxing car to drive in traffic, but then again neither is it uncomfortable - if anything it rides slightly better than a stock GT3 due to tyre and suspension subtleties.

Prod the throttle and you notice another difference with the RS - the lower final drive and a shorter sixth gear certainly make the car more responsive, although for UK use they could be shorter still. Hold it to the floor and the RS will sing 'round to 8,500rpm, with performance as ferocious as you'd expect.

The extra front-end grip and that superb steering give you loads of confidence turning into corners, and of course, in the dry the grip is prodigious: as you might expect on Pilot Sport Cups, at zero degrees with a dusting of snow it all becomes a bit tricky. The ceramic brakes have incredible retardation, but the pedal seemed slightly high on this particular car, making any heel-and-toeing difficult unless you were pushing on the pedal very hard.

Still, so much of this car has been tailored for the track, so it would be wrong to claim this is a full review, based as it was on a day charging at mountain hairpins and another watching giant snow flakes idly collecting on that outrageous plank of a rear wing. That there seems excellent front end grip, allied with the confidence from that wonderful steering, and the aforementioned aero improvements, all point to greatness, but that remains to be seen.

So, while I might have alluded to something sensible earlier about 19 grand price differentials, whether you're standing five feet away from it, sat in it - or best of all - driving it, the RS delivers an Weissach-brewed adrenalin narcotic that blows away those practical arguments. May cars like this long continue to be made. Oh, and if you're not taken with the colours or the graphics, fork out another three grand and you can have what you want. Chartreuse Green perhaps?