Porsche’s 718 Cayman GT4 is waging war on the neutering of the sports car with a new, naturally aspirated flat‑six and a manual gearbox. And that’s just the start of what makes it so special

There’s something missing on the centre console of this Porsche 718. It takes a few moments for me to twig, but now I have I can’t stop the smile from spreading broadly across my face. It doesn’t matter how hard you look for it, you won’t find a Sport button on the new Cayman GT4. Nor a mode switch on the steering wheel, a manettino-style device or anything of their ilk. If you need a five-second summation of this car’s character – and why it’s a thoroughly essential evo machine – you could do a lot worse than remembering the above small observation.

Replacing the 981 Cayman GT4 was always going to be a task fraught with potential controversy. Our 2015 eCoty winner, it’s a car that slayed even such giants as the 991.1 GT3 RS and Ferrari 488 GTB, that breezed every group test it was entered into. No wonder everybody wanted one.

Therein, of course, lay the problem: there weren’t enough to go around, and pretty soon a speculator’s market turned what was meant to be a Motorsport department car for the common man (relatively speaking!) into another brilliant Porsche tantalisingly out of reach. While many cried foul, Porsche’s response was that it simply underestimated demand. This time the promise is that everyone who wants one should be able to buy one.

Then there was the small matter of what might power the new car. As far as we could see, the new GT4 would have a distressingly large hole where the 3.8-litre MA1 naturally aspirated flat-six once sat, an engine now long out of production. Would Porsche really drop the GT3 RS engine in there, perhaps detuned? It always felt unlikely given the exotic nature and unit cost of that motor. Then again, surely it wouldn’t use a version of the 2.5-litre four-cylinder turbo motor either; the thought of that really was too much to bear – and the aghast look on Andreas Preuninger’s face whenever the four-pot was mentioned in the past also made this option hard to give credence to.

What transpired is something no one really expected. An all-new engine, but based on the turbocharged 3.0-litre flat-six from the 992; taken out to 4.0 litres, and without a turbocharger in sight. A new naturally aspirated performance engine in this day and age is an exceptionally rare occurrence; one fitted to a six-speed manual gearbox rarer still. This one makes 309kW and 420Nm, and thanks to the fitment of a heavy, but effective, gasoline particulate filter, it meets all the emissions regulations forthcoming over the next few years. From talking to Porsche’s engineers there’s a very real sense of pride and also the hard toil that’s gone into making this engine a reality.

This, and a good deal more reasons, explains why I’m bubbling with excitement as I turn the nose of RX65 PGE in through the front gates of Knockhill Racing Circuit, where the 718 GT4’s launch event has just finished. One lone GT4 has been left behind, with evo’s name on it. Yes, I could have flown up, and that would, drearily, have been quicker, but when you have the key to Porsche’s heritage fleet 981 GT4 – the very car we drove on eCoty 2015 – well, what would you do? Exactly. Any excuse to drive what remains one of my all-time favourite cars needs to be snapped up sharpish. This won’t be a twin-test, but it’ll be a useful and unusual bonus to be able to compare and contrast new and old in such an immediate and real-world fashion. ‘PGE’ will be my second shadow over the next 48 hours.

I don’t mind admitting I catch my breath when I see the 718 sitting outside the circuit shop. In solid white, and with that huge front bib, extractor vents, even larger rear wing and substantial rear diffuser, it looks as if it’s just been pushed out of the racing workshop at Weissach, doubtless complete with that strangely saccharine smell of spray-on cleaner, potent fuel and fresh rubber that always seems to cling to new motorsport machinery.

With key in hand and with the sweeping road to the circuit and majesty of the eponymous hill in the forefront of my mind, it feels fabulous to be back in Scotland – something of an unofficial home for evo these days. Yet, there’s an even greater treat in store. Starting here means our usual range north is extended: it won’t just be the Border country for us, but the Cairngorms and the spectacular Old Military Road too. In a 718 GT4. Did anyone notice me actually run across the car park with the key?

Who cares. That first start of a new car is always special, and even more so when you’re about to hear – and feel – a crucially important new engine from Porsche. The result is a deep, resonant boxer thump, and even in these first few seconds the character of the new engine is different to that of the old car, which has been assaulting my eardrums at close range for the past near-800km straight. A push of the exhaust button on the centre console increases the volume markedly, although it’s still on the polite side of raucous. Otherwise, in here, it’s all very familiar to anyone who’s driven a 718, albeit with copious Alcantara trimming and the optional lightweight carbon buckets. For me, it’s a perfect driving position, and the GT4’s long-distance capabilities are further improved by other key factors. Firstly, it’s undeniably quieter in the cabin. Not just down to the engine; there’s also less of that idiosyncratic high-frequency thrash – is it cogs meshing? – that characterises the old car’s acoustic signature. Most of all, it’s just much more smoother-riding. Not the stuff of evo dreams? Well, the benefits of that will be apparent soon enough…
It takes a little while to reach our location, but the farther north the A93 penetrates, the more eye-widening it becomes. By the time you’re at the mouth of the colossal valley at the Spittal of Glenshee, there’s a sequence of viciously undulating short straights, and tight corners partially hidden by the crests in the road. I know from experience that it can be the absolute undoing of many a car, so I set my initial pace accordingly, but the GT4 suddenly snaps to attention. The first few downhill braking zones are all that’s required to appreciate the phenomenal power of the optional carbon-ceramic brakes, their abrasive qualities literally audible above even the whine and thrash of the engine. The short shift of the gearlever is slicker than before, too, although no less mechanical and precise in its feel. A heel-and-toe down two gears is a sublime moment, the six yelping with appreciative fury if you manage to time it just right. Not in the mood? Press the auto-blip button on the centre console. Thankfully no longer is it tied up with a Sport mode and the PSM system.

From there, the A93 is fast, with long, sweeping stretches where self-restraint is the only limiting factor to your speed. A vista of almost unimaginable depth and grandeur fills the windscreen at times, and there’s the opportunity to get the new engine working hard. As in the 981, the gearing feels overly long, and we know from speaking to the engineering team that this was one thing they weren’t able to change. So the GT4 will hit a faintly ludicrous 138km/h in second gear and forays into the upper echelons of third are really very naughty indeed. That’s a shame, because not only does it blunt the car’s low- and mid-range acceleration, it also means fewer opportunities to enjoy that wonderful gearbox.

At more normal speeds the GT4 could almost be called reserved. That’s due to two reasons. Firstly, because as soon as the revs go past 2000rpm the exhaust valves shut, even with the exhaust switched to open, and they don’t seem to open up again until 4000rpm. Secondly, there is simply less induction noise in the cabin, full stop. But lower the window and jump aggressively on the throttle and you can hear the intake system gasp urgently for breath, then roar with real ferocity, instantly. And as soon as the motor begins to work hard, so it really finds its voice. There’s a shriek that continues past 5000rpm, then six, seven, and all the way to 8000rpm. It’s a fantastic sound – one that riffs seductively from the Mezger back catalogue in a manner not found in the last of the naturally aspirated DFI units. The need to meet legislative requirements has clearly draped a very thin veil over its ultimate exuberance, but there’s no doubt in my mind this is a beautiful new powerplant.

Those earlier dramatic undulations had opened my eyes to something else about the new GT4. I had remembered them as being an immense test of a car, and to a certain extent a driver’s stomach. But it had felt like the 718 had barely broken into a sweat, and the more I upped the pace, the more it seemed to like it, almost begging for more commitment on my part. Now, with photographer Dean Smith at least partially satisfied that we’ve got some good images in the bag, it’s time to head south to our hotel in the Borders, away from the brooding mountains, partially cloaked as they are in low-hung cloud and almost black unless streaked with one of the rays of sunshine that occasionally peeps through the foggy ceiling, applying a floodlit stripe across a grassy hillside. Knowing that we’re currently 10 minutes the wrong side of locking-up time, and still three hours away, is also a certain encouragement.

It feels like there’s not a soul for 100 miles in every direction, and I’m finally confident to let the GT4 have its head. Pouring the nose into each constantly evolving curve is easy, because the steering reminds me of that of the 991.2 GT3 RS in how it feels light and fluid in your hands, yet every bit as precise and linear. For an EPAS system it is incredibly good and allows you to have total confidence in what the car’s doing, and what it may be about to do next. The other characteristic is that extraordinary damping, an initial pliancy on every compression stroke that, without surrendering anything in the way of control, neutralises instantly almost any awkward bump, camber or anything else the road can throw at it. Far from making the GT4 aloof, it’s a gateway to even more driver engagement.
I’m still buzzing and slightly in awe of the 718 when the rain begins to fall – and does so with a vengeance. As a veteran of the track-based press launch the week before (see last issue), the GT4’s rear bespoke Michelin Cup 2 tyres are past their first flush of youth, and at one point I can barely muster 80km/h on the motorway without the onset of aquaplaning. Suddenly the little Cayman feels very small under the twilight sky, wipers flailing wildly and just a few monochromatic shapes passing for the world outside. It’s a character-building journey, but when we arrive I nearly walk into the old stone archway of our town-centre coaching inn, because my eyes are fixated on the GT4 in the corner of the car park. It’s got seriously under my skin, and I confess I’m helpless to resist it.

The next morning is on more familiar territory, a road we know well that’s a fine test of any car. Sure enough, the GT4 breezes it, but there are two moments that stand out so clearly in my mind afterwards that they come to define the car. The first is the ‘rollercoaster section’, a heinously difficult and narrow stretch about a kilometre long. The GT4 scythes through it. Cuts it down to size and then spits it unceremoniously aside. Even when the camber switches unannounced at the top of the most formidable crest, followed by a blind change of direction, the 718 just wriggles its hips and laughs. Turn-in is immediate, but there’s an even greater sense of pivoting agility once the nose has stuck. If it hasn’t, quite, you’ll know about it, as is the case when we hit a section of damp tarmac with a coarser surface, and the wheel shimmies delicately to signal the lowering of the grip level.

The other is a downhill luge run across the valley floor, with a sequence of high-speed S-bends just slightly too pronounced to be straight-lined. The surface is unusually smooth, but the cambers induce a constant rocking motion. The 718 is poised, yet bonded with staggering purchase, inspiring immense confidence, as if riding on some invisible cushion of air, an absorbent layer of damping it can tap into where required. Could it be the aero making a contribution, too? There’s 50 per cent more downforce, largely thanks to that chunky rear diffuser. I drive the passage again and again, until I feel so in tune with the car it’s almost like an extension of my own body. Don’t go thinking it’s completely benign though: strike a damp patch and it’ll lose traction, quickly, at the rear, well into third gear on occasion.

Things I don’t like about the 718 GT4: the gearing’s too long for fun, fast road use, and the engine could be louder, both in induction and exhaust – but only because inherently it sounds so good. That really is about it. It’s a useable size, has more than enough performance, and drives spectacularly well. It has moved the GT4 lineage along in a way I never thought possible, and now really does feel like a bonsai GT3 – a true younger sibling of the Porsche Motorsport family. And on this showing I still fear Porsche will struggle to build enough of them…

By Adam Towler | Photography by Dean Smith

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