Cars with Jan Coomans: Porsche GT4 RS

Before we get too sad about that, let’s rattle off some more figures. The GT4 RS will do the 0 to 100 km/h sprint in 3.4 seconds, and getting to 200 only adds another 7.5 seconds on top of that. That’s pretty incredible acceleration, not just for a Cayman. The RS is helped by new shortened PDK gear ratios, the shortest ever used in a Porsche GT car in fact. That will show all those journalists who kept complaining about them, I suppose. As with all RS models, the GT4 RS is only available with the PDK dual-clutch gearbox. Downforce is also up by 25 percent over the regular GT4, thanks to the larger swan neck wing at the back and a larger splitter at the front. If you set the car to its highest downforce setting, it’s got just as much as a 992 GT3 in its default configuration.

But let’s get into how the car actually drives. I’m fortunate to own a 718 GT4 (with some modifications) so as you can imagine, I was quite eager to compare it to my own car and see how well I’ve done making it quicker without the full force of Porsche’s engineering department behind me. The GT4 RS Nurburgring lap time was 23.6 seconds faster than the regular GT4, so one would certainly expect to notice that kind of difference. Unfortunately, we would not be driving on the Michelin Cup 2 R which was used for that particular lap time of 7 minutes 9.3 seconds. Instead, the GT4 RS press cars were shod with regular Michelin Cup 2 tires, with the same N1 Porsche spec marking as is found on the GT4.

Inside, the car is very familiar to sit in, as there has hardly been any real change since the 981 generation Cayman and Boxster back in 2013. The GT4 RS does have the PDK gear selector from the 992 GT3, and the dashboard is covered in Race-tex (Alcantara) which fits in with the racing vibe. But other than that it’s the usual cabin with a near perfect layout and excellent driving position. For maximum lightness and performance, the cars used on the racetrack had the PCM delete option (no infotainment system) and were all equipped with the optional Weissach package which means the roll cage is made out of Titanium and it lets you add magnesium wheels which remove 10 kilograms of weight on their own. The Weissach package also adds a bunch of carbon fibre accents on the outside of the car, and the airbox on top of the engine is changed from a plastic one to carbon fibre.

On to the track then, and of course the first thing that jumps out is just how much engine sound is created by the new air intake and airbox. It’s pretty incredible and it overpowers everything else. The power, also, is rather impressive. We’ve known this engine for quite a while now, but it’s hard not to fall in love with it every single time you drive it. It’s just mega. Handing wise, there is no clear tendency for the car to slide more on the front or rear axle, only after a couple of hard laps when the tires had started to lose significant amounts of grip did understeer become noticeable. The steering is super sharp and accurate, even more so than the regular GT4 as the rubber bushings in the suspension have been replaced by solid ones. It means that you’ve got laser-like precision at your disposal to place the car exactly where you want to.

It’s a very, very fast car on track. It’s not entirely on the 911 GT3’s level, thanks to the much more primitive MacPherson strut suspension, so there is still a hint of the «Cayman complex» present if you look hard enough. But it’s really close, and most important of all, a GT4 RS is more exciting to drive. It’s not quite as stable, and the smaller cabin combined with the huge intake sound makes it feel faster than the much more muted and composed GT3. If I say that the GT4 RS has 97 percent of the capability of the latest generation 911 GT3, the engagement factor is probably 197 percent. The suspension is a lot stiffer than in the regular GT4, as the front spring rate has more than doubled, and it really helps the RS feel closer to a race car than less compromised on track than other fast road cars usually are.

All this does mean, however, that if you take a GT4 RS out on the regular roads it feels very much like a duck out of water. It’s not that you can’t drive it around normally at low speed. Of course you can. And the GT4 RS is even pretty quiet on the outside if you do because it’s subject to even stricter noise restrictions than the 992 GT3 was. Inside the car however, the lack of noise deadening material takes its toll. There’s loads of noises coming from the engine department and none of them particularly fruity. It’s just the whirring of a pump, the rattling of a chain, the ticking of the high pressure fuel injectors… it’s more annoying than exotic. If you want the GT4 RS to produce its glorious sound, you have to step on its tail and let it rev to 9000 RPM with your right foot to the floor and the engine’s individual throttle bodies fully open.

But at that point, you feel like you probably shouldn’t be doing this on the public road. It gathers speed so quickly and with such a furious sound that, combined with the sheer stiffness of the suspension, it does actually feel like you’ve taken a race car out on the street. A place where it doesn’t really belong. Sure you can drive it to your nearest bakery in the morning to pick up a couple of croissants. Possibly even a pain au chocolat. But you wouldn’t want to do any sort of long distance road trip, that’s for sure. The main comfort this car offers is that you don’t get wet driving it in the rain.

If not a racetrack, at the very least you need an empty twisty road not too far from where you live and drive until all the stress and frustration from the past working week has left your body. Which shouldn’t take long. An interesting note however is that the exhaust sound of the GT4 RS is actually rather quiet and uninspiring, similar to the regular GT4. Which is fine for me, as I only care about what the car sounds like to the people inside the car. And on the inside, the sound level is GT3 race car. Apparently, the reason for the muted exterior sound is that the GT4 RS, by being launched only now, is subject to even stricter noise regulations than the 992 generation 911 GT3. Anyway, the air intake is so loud that you’d need to put on a very loud aftermarket exhaust to hear it at all.

I had long talks with Porsche ambassador and legendary racing driver Joerg Bergmeister about the car which he effectively developed during countless laps of the Nurburgring Nordschleife. I was quite pleased to find out that he had gone for nearly the same spring stiffness as I had on my GT4, and just like me he had found that the brake bias had to be moved forward a little. Joerg is a great guy who really loves his job (well, who wouldn’t) and it was quite eye opening when he took me for a lap in a GT4 RS which was on the stickier Cup 2 R tires. While I was quite proud of getting relatively close to him in terms of lap time, the way a racing driver makes the track wider than it at first appears is quite amusing. I hadn’t even thought of driving on the green stuff on the far side of the kerbstones, as these areas tend to be slippery on most tracks I drive on. But Estoril is a track with lots of motorbike races, so for their safety it’s almost as grippy as the main road surface. To a pro driver, that’s free real estate and a lot of time gained by driving over it on corner exit.

But in the end, it’s not difficult to distill what the GT4 RS is about, and it’s not lap times. Though it certainly is extremely fast by any standard. Instead, this car is a celebration of the naturally aspirated engine, in particular the magnificent Porsche 4 litre flat six motorsport derived power plant. We’ll be probably able to enjoy it for many more years in the 911 range, but it will never be as raw and exciting as it is in this most ultimate of Caymans. The engine takes centre stage in such a big way that one almost forgets to appreciate the car’s sublime mid-engine handling characteristics which have been fine tuned here better than ever before. I feel privileged to have driven it, even if I may never get to do so again. At least the age old question of what it would be like if Porsche let the Cayman off the leash has now finally been answered.