- 493-horsepower 4.0-liter flax-six taken from the 911 GT3
- Seven-speed dual-clutch features revised gearing
- Track-focused suspension and a glorious noise
A bit of criticism has dogged the Porsche Cayman since its 2006 introduction. Sure, it had wonderful handling characteristics, but it felt a bit underpowered relative to the big brother 911. For 2015, Porsche finally answered the call by taking the engine of the 911 Carrera S of the time and installing it into the Cayman to create the first Cayman GT4.
That was on the previous-generation car. For the latest 718 Cayman generation, Porsche introduced the 718 GT4 starting for 2020. The GT4's naturally aspirated flat-six engine generates 414 horsepower and would seemingly leave little room for improvement.
But, you know, that would be wrong.
Unbeknownst to us, Porsche's 718 engineering team had secretly begun developing a version of the yet unreleased new-generation 911 GT3's engine for use in the Cayman. The result? You're looking at it: the 493-hp 2022 718 Cayman GT4. It's fun, weaponized.
Turns out, it's not so simple as just shoving a 911 engine into a Cayman and calling it a day. For obvious starters, in the 911 the engine is in the rear and the gearbox is mounted in front of the engine. Placement into the Cayman, with its mid-engine layout, meant rotating the engine 180 degrees and then reengineering the coolant lines, oil lines, air intake system and the exhaust system, which is now running in the opposite direction.
Interestingly, the extra length and packaging of the new exhaust system were responsible for a drop of around 10 horsepower from the rating it gets in the 911 GT3. Put on your conspiracy hats if you want, but it's just simple exhaust gas physics that limits the power rather than some sort of artificial limit.
Installing the GT4's transmission took a much more creative approach and involved Porsche's engineers raiding both the corporate and motorsports parts bins. Using a 718 Cayman transmission to start (you can't just flip around the 911's GT3 gearbox), engineers filled it with motorsports parts from the Cayman GT4 Clubsport racer, added extra lubrication and, most importantly, the gear set and axle ratio from the previous-generation 911 GT3 RS.
That's major news because up till now the Cayman has inexplicably been saddled by needlessly tall gearing. This custom transmission is a seven-speed PDK (Porsche-speak for a dual-clutch automatic) with no overdrive gears meaning it can (only) reach its claimed top speed of 196 mph in seventh. This is the shortest gearing available in any GT car Porsche currently sells and allows the GT4 RS to out-accelerate all other production Caymans by a substantial margin.
The noise this thing makes is just so good. While Porsche engineers have taken some measures to limit unwanted resonance and vibrations, they haven't done much. The GT4 RS produces a mechanical roar at lower rpm that transforms into a full-on howl over 5,000 rpm. It's a mix of intake and exhaust that's pure motorsport and has strange similarities to Tuvan throat singers, producing two or more tones at once. It's the signature Porsche sound and absolutely intoxicating.
Part of the reason that noise is so prominent is because the rear quarter windows, the ones just behind the driver's and passenger's heads, have been replaced with air intake scoops. These scoops feed directly into the intake manifold, which also happens to be directly behind your shoulders. Running without hearing protection, or a helmet, for an extended period of time at higher rpm will likely give you one hell of a headache.
But as the engine tears toward its 9,000-rpm redline, you just won't care. Throttle response is immediate and upshifts from the PDK automatic are just as fast as we've come to expect and without any unnecessary theater. Downshifts are the same — they're crisp and happen as quickly as you can pull the steering wheel-mounted paddles. And the sound on the downshifts … unnngh. SO good.
It would be easy to say the engine is the star of the show. It's a 4.0-liter flat-six that revs out to a scarcely believable 9,000 rpm and rips out 493 horsepower and all without the benefits of turbos or hybrid assist. Throttle response is instantaneous and crisp, but power can be meted out with the utmost precision, which is especially helpful through long, sweeping turns. Even though torque is relatively low at 331 lb-ft, there's still plenty of tap to whip the RS into a lurid slide with a healthy flex of your right foot.
You'll have no trouble collecting up that lurid slide thanks to the GT4 RS's deft handling. With quick responses and excellent accuracy and feel, the GT4 RS comes across like a big go-kart. You can position the car not only with the steering, but with the throttle or the brakes thanks to the RS's very special mechanical limited-slip differential. Taken from the previous-generation 911 GT3, the differential provides predictable traction under both acceleration as well as braking and allows the driver to make minute adjustments to help rotate the RS through a corner. Being 47 pounds lighter than the standard GT4 with a PDK doesn't hurt either.
Among the suspension modifications, front spring rates have been increased twofold while the rear rates are up only slightly less. Struts are specific to the GT4 RS, and ball joints, instead of softer bushings, have been used for mounting points for both the front and rear suspension for more direct responses and improved feel. When Markus Atz, project manager for the GT and 718 model line, was asked if the loss of on-road ride comfort was a concern, he replied with a succinct and simple, "No."
The GT4 RS was built to do its best work on a circuit, and during our time on The Streets, a technical road course that's part of the Willow Springs complex, the RS simply excelled. Lap after lap, the RS remained consistent, allowing us to experiment with slightly different lines, throttle and steering inputs. That consistency and predictability allow you to build confidence and get faster — the hallmark of a truly great car.
Starting at the front, the nose of the GT4 RS is actually that of the previous-generation 911 Carrera 4S. It's been grafted onto the front of the Cayman for better cooling and improved aerodynamics. The front fenders and hood are carbon-fiber, and those scoops on the hood (they're known as NACA ducts) are for cooling the front brakes. The standard wheels are forged aluminum and mark the first time center-lock wheels have been fitted to a 718 Cayman.
The front brake discs have grown from 15 to 16 inches in diameter and use six-piston calipers to stop them. Of course, carbon-ceramic brakes are available and are a very worthwhile option. Those carbon-ceramic brakes will have no problem holding up to a full day of track use, and track use is why you're buying the Cayman GT4 in the first place.
The rear wing looks a little different thanks to its "swan neck" struts. This design cleans up the airflow under the wing, making it more efficient. The rear wing is adjustable, and there are underbody adjustments to allow for better airflow management. All told, at 125 mph, Porsche says, the GT4 RS makes up to 25% more downforce than the standard GT4.
Even though it's most at home on a racetrack, the GT4 RS feels quite similar to any other current-generation 718 Cayman. Standard equipment includes Porsche's full bucket seats, which demand a certain, shall we say, slenderness to find truly comfortable. Faux suede abounds, and though the interior looks very purposeful, it's far from spartan. Dual-zone climate control, the usual infotainment screen and power windows are all standard, while heated seats, an upgraded Bose audio system and extended leather upholstery are all available. Oh, and the gear selector? That's straight out of the 911 GT3.
Porsche also offers a Weissach package, adding forged magnesium wheels, more visible carbon fiber, titanium exhaust tips and other unique touches, while a custom Porsche Design watch to match your GT4 RS is also available.
While some have wondered if the 718 Cayman would ever get performance it really deserved, engineers at Porsche were busy stuffing its mid-engine sports car with a 911 GT3 engine and more motorsports parts than you can shake a stick at. The result is a stunning street-legal track car imbued with all the goodness of the standard 718 Cayman but cranked up to 11 with the help of some real enthusiast engineers. If you're in the market, and REALLY good friends with your local Porsche dealer, prices start at $143,050 including destination fees. Excuse us while we try to scrounge up a down payment.