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Feature

21 Nov 2019

Photos by Barry Hayden

Weissach’s mid-engine masterpiece

Armed with six finely tuned cylinders the new 718 Cayman GT4 packs a punch

When the 718 range was unveiled in 2016, the instant apoplexy surrounding its turbo-charged four-cylinder engine was curious to behold. Here was a car whose superior performance was only begrudgingly acknowledged, and where the overwhelming criticism was that the new car didn’t sound like the old one.
 
There were always questions marks over what the GT department had in store for the next generation GT4 and Andreas Preuninger and company have once again caught us all on the hop.
 

 
The frequently and not always fairly maligned four-pot has been left on the shop floor, replaced by a completely new engine that, against industry expectation, is unrelated to the 3.8-litre flat-six inherited by the latest track-only GT4 Clubsport from the previous gen GT3. Instead, Weissach has created a new powerplant based upon the existing 4.0-litre boxer currently on duty in the 992 Carrera. But it is a substantially different beast, relieved of the efficiency-oriented twin turbos and heavily bored and stroked.
 
The internally coded 9A2 Evo has been developed specifically for mid-engine applications and is substantially cheaper to produce than its bespoke GT3-derived predecessor. Nevertheless, it spins up to 8000rpm and produces a useful 414bhp in the process, a gain of some 34bhp over the previous generation car. It’s also relatively future proof, with Piezo injectors exactingly regulating fuel delivery and the ability to shut down three of its six cylinders during constant cruising.
 
The 718 chassis this engine is bolted to was already something of a masterclass, a careful evolution of the 981 with MacPherson struts all round, more stiffly sprung and benefiting from beefier anti-roll bars. Steering was more direct, the rear subframe strengthened and the wheels widened for greater traction and grip. In short, there wasn’t, and still isn’t, a better chassis set-up in the small sports car segment. Ripe territory, then, for a sprinkling of the GT fairy dust.
 

 
And just as with the first GT4, the underpinnings of the new car are a generous Weissach wish list, with the front axle lifted lock stock from the GT3 while the rear has a new damper set up and the GT3’s subframe. Two-way adjustable suspension enables a simple switch between road and track set-ups too, as telling an asset as the unique 20-inch wheels are shod in semi-slick Michelin Pilot Sport Cup 2s.
 
The Weissach team have also dedicated a great deal of time to the aerodynamic possibilities of the new GT4, exploiting the space made available by that mid-engine configuration to install a substantial new rear diffuser that significantly enhances the car’s overall downforce. In combination with a 20 per cent more efficient new rear wing, downforce over the rear axle hits 12kg at 124mph. Overall, downforce has been increased by a remarkable 50 per cent, all apparently without adversely affecting drag.
 
And given the once over, all this seems entirely plausible. From any angle the GT4 screams motorsport, from the extended chin spoiler and capacious air scoops to the PASM-induced 30mm lower stance and that Ronseal fixed rear wing. Inside, the message carries over with acres of Alcantara, bolstered by the optional Clubsport pack’s body-hugging fixed bucket seats and half-cage, the latter of which does a good job of obscuring what was left of your rear view after the wing arrived.
 

 
This particular GT4 is AG’s left-hand-drive press car, so currently on the wrong side of the road to be on the wrong side of the car. Porsche’s GT products are always mildly intimidating over the first few miles, so this ought by rights to be a thoroughly unnerving experience. And yet, not a bit of it. The 718 GT4 is utterly approachable amid the mandatory weave through urban traffic and congested motorways en route to some decent driving roads. The engine, although blessed with a distinctive chatter at low revs, is a far cry from the persistent aural threat delivered by the GT3’s race-derived unit. Which some may lament, but it does make it a markedly less stressful car to pootle about in.
 
Opened up, the long gearing for which the previous gen GT4 was criticised is still in evidence, but this at least serves to make the driving experience less frenetic on major roads. The 420Nm of torque on offer peaks at 5000rpm, some 3000rpm below the red line, so you can cruise in relative comfort, albeit with a fairly intrusive level of engine noise.
 
But on a faster driving road, the GT4 is, of course, in its element. The suspension is incredibly supple, even in PASM’s more focussed Sport mode, and rides out surface changes and substantial undulations with surprisingly little transfer to the cabin. This is not something you’d expect from any sports car, let alone one running ball-jointed suspension and 295/30/R20 tyres. 
 

 
Get the tacho past 5000rpm and the 9A2 Evo changes character, the chatter becoming a holler, the flat-six tenor back where the dewy-eyed purists wanted it. In any given gear, and at almost any revs, it feels as if there is always something in reserve in the GT4, something that could quickly turn ‘rapid progress’ into ‘prison’.
 
Leant on in the corners the GT4 feels staggeringly composed, absent of determinable roll and willing you back on the power ever earlier. Keep the revs in the sweet spot and the car absolutely explodes out of the turns with an animal ferocity, the instant response of natural aspiration devouring the road ahead.
 
Mercifully, the single most impressive thing about this car is its brakes. Front and back these are 380mm composite discs with aluminium monobloc fixed callipers which scrub off speed with unholy alacrity. And the pedal feel is tremendous, short in travel, almost immediate to bite and full of feel. If there’s one thing you want in a road or track car with this degree of go, it’s a comparable capacity to stop and the GT4 absolutely nails this.
 

 
There’s little doubt that the improvements in the 718 chassis make this car an authentic and hugely impressive addition to the GT stable. The engine is a curious thing, not quite as committed to the cause as the GT3’s, yet a far cry from the turbocharged flat-four. It’s not unreasonable to speculate that, having developed this unit uniquely for the 718 platform, we will see lesser cars in the series finding themselves back in the six-cylinder club before long.
 
But for now, the 718 GT4 is the first of an exciting new breed of Caymans, and it is more than enough to be getting on with. Porsche recently put a road legal GT4 around the Nordschleife in 7 minutes 28 seconds, some four seconds faster than the Carrera GT, a once in a generation all-carbon V10 hyper car. Such is the dizzying state of progress that this sort of performance can now be yours for £75,000.

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