Porsche 911 GT3 RS review

That wing also has a hydraulically actuated active drag-reduction vane (and it works), along with new similarly active downforce-generating flaps under the car’s nose, to produce up to 860kg of downforce at 177mph. That's more than double what the last 911 GT3 RS made; more than the McLaren Senna makes at a similar speed; and considerably more, even, than a 911 GT3 Cup competition car. When Porsche’s development drivers get out of the new RS road car and into one of Porsche Motorsport’s slick-shod junior racing machines, they actually have to remind themselves to slow down a bit.

The clever bit is that all of the new RS’s downforce is only ‘on’ when the car needs it. At the touch of a button, the active aero can be switched off instantly and almost entirely for cleaner-cleaving straight-line pace. Or you can leave the car to decide for itself when you need the extra grip and when you don’t.

Porsche has worked to offset the extra weight of the car’s wider body, wider axles and bigger wheels, and of the various servos and electric actuators of that active aero system. The RS gets carbonfibre-composite front wings, bumpers and doors as well as the CFRP roof and bonnet that we’ve seen on other high-end Porsche GT cars. It can even be had with a carbonfibre rollover bar as an alternative to the Clubsport-package steel one. But, at its lightest, it still comes in 15kg heavier than a GT3 in equivalent trim.

The car’s straight-line performance hike, meanwhile, comes from some hotter cams and shorter gear ratios.

If Silverstone had been warm and dry on the day of our test, I might very well now be gushing about this car’s incredible lateral grip, high-speed stability and outright stopping power. As it was, in the wet, it was quite tough to judge what the GT3 RS adds over and above the already-formidably-fast GT3’s circuit capability. Tough, that is - although not impossible.

The 911 GT3 RS isn’t notably quicker-accelerating than a standard GT3, but it does have that dartier steering response and keener sense of agility that has characterised wide-tracked RS cars for so long. Even in the wet, you can feel that active aero really working – pushing the chassis groundward on its wheels and adding reassuring adhesion through quicker bends, only to ease off again through the slower ones and remind you how little pure mechanical grip a wet and greasy surface might otherwise be granting you on cold Cup tyres.

Porsche's operating plan for the test driving was to have an instructor in a regular GT3 lead each RS-driving journalist around the Silverstone Grand Prix circuit, the former adapting his speed to the competence and confidence of the latter, or so Porsche had thought. As it turned out, through fast corners like Abbey, Stowe and Maggots, it was amusing to watch the expert racing drivers up ahead struggling for high-speed grip and braking stability, their lesser GT3s squirming around and locking up, from the relative security of a car that was just sticking to the track better.

On a very wide and smooth race track, it was impossible to even begin to judge how the GT3 RS might ride on the road; and with spring rates cranked up 50% even over the already high settings of a regular GT3, it seems reasonable to wonder. We will wait and see.

The car does come with one acknowledged compromise on usability: there's no 'frunk' at all on this 911. Porsche had to rework the car's cooling system in order to make room for its active aero, and the new central radiator (based on the S-Duct concept of Porsche's race cars) takes up the space where you might otherwise have carried your luggage.

Back in the driver's seat, the RS’s new multi-adjustable adaptive dampers, active locking differential and traction and stability control systems bring a level of instant driver configurability to the car that we’ve not seen from Weissach before. Through four rotary knobs on the steering boss, you can wind the car’s dampers up and down for both compression and rebound - even to levels softer than a regular GT3’s, if you want to. You can also manually and individually adjust the diff-locking settings for both drive and coast modes.

On the face of it, it's a complicated process to contemplate while half way around a fast lap; but once you're used to selecting each area of adjustment in turn with each knob's central button, then cycling the settings up and down as the function of each adjustment wheel changes in line with the labelling on the car's instrument display, it's surprisingly easy to do it. Want more handling adjustability? Just switch back the traction control, soften up the compression damping a little and loosen up the differential's coasting lock calibration. Want better compliance over bigger kerbs? Take one slow pass down the Hangar straight, clickety-click and you've got it. 

This GT3 RS is clearly a more serious and much more purposeful track tool than any of its predecessors, but it's cleverer and more adaptable, too. On an imperfect rainy day in Northamptonshire, it was remarkably benign yet also quietly brilliant in its way - while it was deeply frustrating not to be able to experience the car differently.

In its intended conditions, when diving deep into braking areas and carrying speed like a racing prototype might, I dare say it ought to be little short of sensational, but we will hold off with a rating for the car until we know that much for sure.