Porsche offered up a test day recently at Road Atlanta, just outside the hometown of Porsche North America, for its two most track-capable street-legal machines. They have a fabulous new facility at the end of a runway at Hartsfield-Jackson. Since the track is only 15 minutes from my home, I was not going to miss it. Of course, I was at a California track the day before, so I red-eyed in just in time for the rain to quit on day three. The track gods smiled on us this time!
Lined up on pit lane were 911 GT3RSes in all three colors, four Cayman GT4s, and only two “journalists” other than myself to drive them. Heaven. Both these athletic sprinters have been revised from end to end for lapping road courses, complete with real wings. I am a big fan of downforce.
This is the second time I have sampled each of these, and I was inspired to attend by opposite handling characteristics: oversteer and understeer. Too much of either is a problem. And we want that perfect balance, ja? Of course, that varies from one driver to another, and something I admire about Porsches GTs is their tunability.
The Cayman GT4 is the upstart with an engineer’s ideal mid-engine placement, a counterpoint to Porsche’s flagship, the classic rear-engine 911. It’s up to 385 horsepower now, a further feeding for a chassis hungry for more. And for the purist it has a driver-intensive manual transmission with one of the best shifters to be found anywhere.
When I drove this car at Motor Trend’s annual Best Driver’s Car, it felt really good on the road, but the racetrack revealed a shocking degree of understeer and an annoying level of stability intervention. Our Porsche reps took the car to check alignment. It was a step in the right direction but still uncharacteristic of a Porsche, not to mention a GT. I got so frustrated that I crawled under its gorgeous body and adjusted the anti-roll bars myself: full soft front, full hard rear, textbook to reduce understeer. It certainly helped, but the overriding feel remained a numbing push, hurting the response through the middle of the corners.
Among the four GT4s on pit lane was the very car I drove out west. From the first lap, it was clear we were in a new ballpark. The planets were back in alignment, as were the wheels and ride heights. These vaunted GT Porsches have racing coil-over spring/shock assemblies with adjustable perches. They require a genuine track alignment that sets the load on each wheel very precisely. Corner weighting, in competition speak. Apparently, our first car was off-kilter because now the Cayman was back to its old wonderful self. Attacking Road Atlanta in full banzai (wink, wink, Herr Germans) mode was a natural occurrence, the car begging for the whip on its flanks. The wing was an effective aid in the tricky drop into the esses, where cars always get light as the road falls away.
The Cayman GT4 also excelled at accel coming off the slower Turn 7 and Turn 10B, helped by the effective Porsche torque vectoring with locking differential. It always put power down well. However, I found I had to be careful braking into Turn 5, which includes a strong transition at the end of the esses, custom-made to destabilize a chassis. Further, in direct back-to-back drives, the Cayman felt slightly underdamped and a bit softer than the GT3RS over the same bumps. These factors were truly minor, and I greatly enjoyed pushing the GT4 like the many race cars I’ve campaigned at this historic Atlanta circuit. Striving for perfection and full speed in every corner is very rewarding in this ultimate Cayman.
I had the pleasure of testing the GT3RS once before, at the international launch at the torturously entertaining Bilster Berg circuit in Germany a few months ago. I was enthralled by the Porsche engineer’s long description of the track-oriented upgrades for this model. They touched nearly every piece of the standard GT3, and I believe them when they say they enjoyed the process. See the Motor Trend video below and story of that test for more.
Leaving pit lane and heading up the very steep incline into Turn 3, I was immediately impressed by the power. It clearly surpasses the GT3, crushes the Cayman, and makes me nostalgic for the almost-gone days of natural aspiration. Five hundred peak hp at 8,250 rpm. Glorious soaring power and soundtrack. Brumos Porsche Racing legendary hosts Hurley Haywood and David Donohue both reassure that the new turbo engines coming are really satisfying, but I say grab one of these while you can. The PDK trans is a joy, but it’s so easy and fast that it definitely reduces driver effort and involvement. Porsche does this better than anyone still. The Cayman’s slick six-speed manual feels antique in comparison but so engaging. Yet pull that gear lever into the wrong slot, Mr. Human Being, and it’s the quickest way to spin, crash, or overrev and destroy that fine flat masterpiece hanging close to the pavement behind you. One slipup will cost you $$$. The PDK eliminates that risk, and it’s faster, and I support Porsche’s decision to equip the RS with it only.
I’m rereading the specs, and the technology makes me giddy. Raises my pulse. Rear-steer, dynamic engine mounts, like the PASM shocks, that also magnetically adjust constantly for comfort or performance depending on suspension loads, torque vectoring that uses inside rear braking to improve turn-in. Utterly amazing. And it states right in the factory description that anti-roll bars, camber, and ride height are adjustable for taste.
I’m pleased by that because I always seem to find that Porsche track/race cars, unlike most of the automaker’s street efforts, are not perfectly balanced but are delivered with too much oversteer blended in and other surprising handling issues. Perhaps such things are seen as sporty? Fortunately, adjustments can correct or add characteristics more to specific driver tastes. Boutique style.
What impressed me the most is the sublime control of the PASM shock damping combined with the dynamic engine mounts. Remarkably refined and better than its little brother, the GT4. This car is so very well tied-down on track yet not harsh on the street, and it eats curbing without disturbing its line on track. Braking is another high point, withstanding relentless corner attacks with a consistent, firm, and linear pedal feel, the world standard on track with no compromise on the street.
I’m less than thrilled with this 911’s ability to put its 500 hp to the ground. In second gear, wheelspin-induced oversteer is easily provoked in all-natural form with the stability controls off. I felt this in Germany, too, but not in the GT3. Perhaps this can be improved with a little more front anti-roll bar. I plan to find out.
We started the day with a warm-up that quickly turned into hot laps following Donohue. This rousing almost-race put a wide smile on our faces, using these wonderful playthings fully for their intended purpose. For perfection, I still looked for more stability at the limit. For a balance that would make me comfortable driving with reckless abandon, knowing exactly what would happen. The sizable wing was in its level position, so I asked for more, being a devout disciple of downforce. The willing Porsche reps went all the way to max, position three, a visibly significant increase in angle, but it felt as if we’d lost a bit of rear grip. Maybe the middle position offers the maximum effect. We’ll try that later, as well.
Up front, we removed the screens from those trick and effective fender vents, and that resulted in a clear increase in front grip, but those went back in because what I really wanted was more stick on the hind end. The whole process of these changes reminded me so much of my career of working with a race team to optimize performance.
In sum, we have the ultimate Cayman, now up to nearly 400 horses, and a 911 in street form that can darn near race with the Cup cars. Both are capable of being fine-tuned to the driver’s preference, and both deliver track performance and satisfaction among the very best in the world.