The Porsche 718 Cayman GT4 and 718 Spyder are just flat (six) wonderful

If you’re in the habit of rooting for the underdog, chances are you won’t find yourself on Porsche’s side of the stadium very often. Their sports cars are predictably competent, predictably expensive for their feature sets—and just as predictably, they are marketplace winners. This goes double for the GT-badged efforts, which have spent the last decade generating waiting lists in dealerships across the globe.

It’s therefore easy to predict Porsche’s speedy application of the GT-whatever formula to the new versions of its 718 mid-engine cars, which is how we arrived at the new 718 Cayman GT4 and the 718 Spyder. They share mechanicals, but there’s one significant difference: the Spyder doesn’t wear the outrageous wing of its Cayman GT4 sibling.

Thankfully, they’re both blessed with a screaming flat-six in place of the good-enough-but-unglamorous four-cylinder turbo found elsewhere in the 718 line.   Frank-Steffen Walliser, vice-president of the 911 and 718 product lines, is quick to dismiss any notions that this is an upsell disguised as sporting necessity.

“Going back when the decision was made, [the four-cylinder 718] was mainly driven by CO2 and emissions regulations,” he said. In China, where cars are heavily taxed based on engine size, sales of the turbo 718 have been strong. “Response was cool in the West, not to the base model [718] but in mid-level S and GTS models.”

In other words: The four-cylinder program isn’t ringing the bell as hard as Porsche would like. So (re)-enter the flat six. It’s not rocket science. The outgoing Cayman GT4 was beloved by critics, collectors, and track-rats alike, so it’s not like the engineers needed to do anything drastic.

Changes focused on horsepower and high-speed stability. Aerodynamic improvements come from an enormous rear diffuser, made possible by a single exhaust silencer shaped like an upside-down “U.” Porsche claims 50 per cent more downforce in total, without any more drag. It’s a technical tidbit with which to bore your friends, rather than a tangible improvement to be enjoyed on a daily basis.

The engine—9A2 Evo in Porsche-speak—is from the turbocharged 911 Carrera, enlarged to 4.0 litres and shorn of the twin turbos. Headline figures are: 414 hp (34 more than the old GT4) at 7,600 rpm and the same 309 lb-ft of peak torque over a higher, wider rev-range (5000–6800 rpm). The motor now uses direct piezo injectors and cylinder deactivation to reduce emissions.

The new GT4 is heavier, by 45-55 pounds with equivalent options, according to GT division boss Andreas Preuninger. He blames emissions equipment and the new rear silencer. With a full tank, the GT4 and Spyder are listed at 3130 pounds.

Drag racers beware: The new cars are still slower from 0-60 than a Boxster GTS with PDK transmission, but the claimed 0-60 mph in 4.2 seconds is entirely respectable, and outright acceleration is missing the point. The turbocharged 718 GTS benefits from a computer-controlled, high-pressurized torque curve, while the GT4 must spin to win.

“Mankind is linear,” Porsche’s Walliser joked. “Normally we fail when things aren’t linear. Like in Chernobyl, they thought the reactor was linear, but it wasn’t.” Now, turbocharged motors aren’t as bad as Chernobyl, but you see where he’s going.

Porsche launched the new GT twins in Scotland, a place where the clouds always threaten rain. Mercifully, it was just a threat during our drive in the drop-top Spyder.

On the narrow, undulating, roads north of Edinburgh, it’s evident why this car is no underdog. The chassis is transparent, the steering fizzes with information. From the moment you roll away, the tidy Alcantara-wrapped steering wheel is moving around in your hands. It transmits bumps and cambers and everything else the front wheels are doing. The steering is so light and delicate that all of the information coming through never becomes tiresome. The rack is electrically assisted, as before, but at this point: who cares? It’s really good. Or, rather, very linear.

The Spyder flows through corners in controlled fashion—and that’s always expensive. The bill-of-materials for suspension components is double what it is on the regular 718, Walliser admitted. The front end is lifted from the GT3, while the rear is heavily revised with helm joints and extra aluminum bracing.

There are minor prices to be paid for this thoroughbred provenance. It takes a long stretch of road to spin the motor to 7600 rpm, even in second gear. Damping quality is typically excellent, but at low speeds on city roads it could get tiresome.

The six-speed manual gearbox is still among the best. The clutch pedal has a fine, granular feel that makes it easy to use and the shifter—now shorter—slots into gears with a solid, chunky action. A PDK automatic will be an option on both the Spyder and GT4, but not until next year.

One note about the roof: the 2011 Spyder had a makeshift top, meant for fair-weather use only. The new one uses a traditional folding roof which Porsche promises will stay attached at 187 mph and—wait for it—will not leak in a car wash. Hallelujah.

When it was time to drive the GT4 at the ancient Knockhill circuit, the clouds made good on their earlier threat, drenching the tarmac. Ex-Formula 1 nice guy Mark Webber—who was on hand basically because Porsche paid him to be—described the track conditions as, “borderline acceptable.” Low fog and standing water, “can make it pretty tricky,” he added.

The soaked track only proved how beautifully the GT4 is balanced. (Because it has the engine in the middle, where it should be.) This car is a blank canvas for a good driver, rewarding careful inputs with predictable response.

In these conditions, the Auto Blip rev-matching function is helpful if your downshifts are not smooth as Mr Webber’s. Unlike in the previous GT4, there is a dedicated switch for auto rev-matching. It replaces the Sport mode button, because it was redundant; this whole car is sport mode.

The hardtop GT4 was always going to be the presumptive favourite in this pair, and so it is. Annoyingly. However, the Spyder was the car that sparked more joy; it doesn’t take itself quite so seriously.

Both the new GT4 and Spyder will hit dealerships next Spring, priced at $99,200 and $96,300 respectively. Production is not limited to any specific number, according to Walliser. “These are not only for selected buyers who have a collection of five GT3s,” he said. That should come as good news for anyone who missed out on the previous GT4, but bad news for speculators who paid way over list on that car.

How long can Porsche keep making linear cars with naturally-aspirated engines and manual transmissions? “At the moment, I would say for the next 15 years,” Walliser said. “Until after my retirement.”