The Porsche 718 Cayman GT4 Brings a Glorious Flat-Six Back to the 718 Family

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From Car and Driver

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  • The 2020 Porsche 718 Cayman GT4 is the new range-topping performance model in the 718 Cayman lineup.
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  • Rather than the turbocharged flat-four engines used in other Caymans, this model has a naturally aspirated flat-six.
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  • The 718 Cayman GT4 will go on sale next spring with a starting price of $100,450.

It has been three years since the Porsche Boxster and Cayman ditched their naturally aspirated flat-sixes for turbocharged flat-fours. While we still haven’t made peace with that change, Porsche’s bean counters say customers didn’t seem to mind. Like their predecessors, the 718 models find about 25,000 new owners a year globally, and the impressive performance figures speak for themselves. Despite that, the new 2020 Porsche 718 Cayman GT4 confirms what corporate actuaries won’t admit: Cars this good deserve equally special engines.

The new 718 Cayman GT4 uses a 4.0-liter, 8000-rpm, bored, stroked, and turbo-free version of the 992-generation 911’s 3.0-liter 9A2EVO engine. Hitting the high notes requires new cylinder heads, valves, pistons, connecting rods, and crankshaft. The intake manifold, with two resonance flaps, is also new. The free-breathing six-cylinder makes 414 horsepower at 7600 rpm and 309 pound-feet of torque from 5000 to 6800 rpm. That’s an increase of 29 horses over the 2016 GT4, which made identical torque. The only gearbox paired to this engine is a six-speed manual. Porsche says it could have wrung 400 horses from the turbo four that powers the 718 GTS but used this flat-six instead to avoid turbo lag altogether.

Why not detune the GT3’s 4.0-liter engine instead? Because when Porsche flips its flat-sixes 180 degrees to mount them in the middle (with the transmission behind the engine), that leaves no room for the 911 GT3 ‘s external oil tank. Even without borrowing the GT3’s magic, Porsche promises this engine will deliver the nasty cold starts and raspy symphony of its classic (or three-year-old) models.

In modifying this new model from the current-generation 718 Cayman, Porsche spaced the exhaust pipes farther apart as on the GT2 RS and stretched them into ovals that sit in a large new diffuser. The low stance, new front bumper, larger side intakes, and towering wing identify the GT4 as the top of the 718 Cayman food chain.

The GT4, which Porsche says can hit 188 mph, has an adjustable wing that helps it generate 50 percent more downforce than the last generation did, up to 330 pounds. It borrows the 911 GT3’s front suspension and brakes-15.0-inch rotors all around with six-piston calipers up front and fours in the rear, or 16.1-inch front units and 15.4-inch rears with the optional carbon-­ceramics-and adaptive dampers from the GT3 RS. The ABS and stability-control programming are RS spec, too.

The anti-roll-bar end links, camber, and toe can all be manually adjusted, although the ride height-1.2 inches lower than a standard 718’s-is fixed. A clutch-type limited-slip differential with brake-based torque vectoring pairs with electric power steering. The GT4 has wider tires than in lesser models, with 245s at the front and 295s at the rear; Porsche fits either Michelin Pilot Sport Cup 2 or Dunlop Sport Maxx Race 2 tires on new 20-inch wheels. At roughly 3300 pounds, the GT4 is heavier than before, in part because of the enlarged diffuser and a bigger starter motor. It is also nearly 200 pounds heavier than the Cayman GTS by Porsche’s reckoning, although fans of the flat-six will likely forgive the extra weight.

While the new engine employs the usual composite oil pan, forged pistons, and plasma-coated cylinders, it’s the first flat-six Porsche to feature cylinder deactivation. Deactivating the auto stop-start function disables the cylinder deactivation. As in previous GT4s, there are no driving modes. These cars are always in Sport, although a button allows drivers to enable or disable automatic rev matching. In all other manual 718s, rev matching can’t be turned off unless you’re willing to forgo stability control, too.

U.S. models get pull straps instead of door ­handles and either one-piece buckets or 18-way power seats. Europeans can delete the stereo and order a roll bar, six-point harnesses, and a fire extinguisher as part of the Club Sport package. Otherwise, it’s an all-black affair on both continents, with silver stitching and faux suede on the seat inserts, steering wheel, and shift lever. Full leather is available with silver, yellow, or red stitching.

When the Cayman GT4 arrives next spring, it will cost $100,450 to start, which is $18,500 costlier than a manual Cayman GTS and $2900 more than its new Spyder sibling.

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