Visually, the new Porsche 718 Cayman GT4 RS makes no secret of its high performance. The striking rear wing with its swan neck attachment, the NACA air intakes in the bonnet, the extra air intakes behind the side windows — the GT4 RS is clearly recognisable as the flagship model in the 718 range. With the front diffuser and rear wing in their performance position, a setting reserved for use on racetracks, the 718 Cayman GT4 RS generates 25 per cent more downforce than the 718 Cayman GT4.
A rear wing like a Le Mans winner
Even at first glance, the new rear wing of the 718 Cayman GT4 RS catches the eye. The fixed CFRP wing with black side blades and swan neck attachment is derived from the one fitted to the Le Mans class-winning Porsche 911 RSR GT-racing car. The current 911 GT3 was the first Porsche series production car to have this feature. Now the 718 Cayman GT4 RS also benefits from its aerodynamic design. This concept – which holds the wing from above via two firmly attached aluminium struts – results in as little disruption as possible to the airflow beneath the wing. This is only briefly interrupted by the struts and is reunited directly behind them, as a result striking the underside of the wing in a concentrated packet of air. A powerful and constant airflow at this point is more relevant for downforce than the flow over the top. With the car’s rear wing, the effect is the exact opposite to that of an aircraft wing where the air flows faster over the top in order to generate lift.
The angle of attack of the rear wing on the GT4 RS can be manually adjusted in three stages. The same is true of the front diffuser, which can be adjusted in four stages using mechanical sliding elements. This means that a bespoke aerodynamic balance can be attained as required, bringing the vehicle perfectly in line with the track and the driver's preferences.
Innovative routing of process air
As the eye wanders from the trailing edge at the rear of the car, with its integrated third brake light, towards the front of the vehicle, it lingers on the new air intakes behind both the driver’s and passenger’s side windows. Where one would normally find small triangular windows on all other models of the 718 Cayman, the GT4 RS has process air intakes for the 368 kW (500 PS) 4.0-litre boxer engine. The side air intakes behind the doors serve to cool the six-cylinder engine.
An examination of the front of the vehicle reveals four openings which have never been seen before on any model in the 718 range. On top of the wings are wheel arch vents with slats. These slats, a motorsport-derived design, were first used in series production in the 991-generation Porsche 911 GT3 RS. Particularly at high speeds, they reduce the excess pressure in the wheel arch caused by the rotation of the wheels. This is effective in preventing lift on the front axle. Two NACA air intakes give the lightweight bonnet its characteristic appearance. The air intakes were originally developed by the National Advisory Committee for Aeronautics (NACA) — the predecessor of the NASA space agency — and combine two properties that are normally mutually exclusive: they improve brake cooling but without impairing the drag coefficient of the vehicle, which is why NACA air intakes are also frequently used on racing cars.
Vacuum at the rear sucks the GT4 RS onto the road
The entire front bumper area of the 718 Cayman GT4 RS is derived from the GT4 but has been aerodynamically optimised. For example, the front splitter has been redesigned and fitted with flow-around side blades. This improves ventilation and airflow through the wheel arch, further increasing downforce on the front axle. The air flowing under the GT4 RS is greatly accelerated via new deflectors on the fully clad underbody, creating a vacuum at the rear. This provides more downforce at the rear axle.
There are two further NACA air intakes in the underbody of the GT4 RS. They are also used for cooling — the main beneficiary being the gasoline particulate filter — without a negative impact on the car’s overall drag coefficient. Finally, the air flowing under the car exits through a rear diffuser. This component has been taken from the 718 Cayman GT4 and improved using aerodynamic fins on the sides. They provide additional stabilisation of the airflow at the rear and have a positive effect on downforce.
Lightweight construction techniques cut weight by 35 kg
While the aerodynamic elements designed to enhance the new car’s driving dynamics are clearly visible, another performance-enhancing characteristic lies hidden within the body: its lightweight construction. Measured according to DIN standards — fully fuelled and without a driver — the 718 Cayman GT4 RS weighs in at 1,415 kg. Thus, each one of the engine’s 500 PS is responsible for accelerating just 2.83 kg (3.8 kg/kW). To achieve this goal, both the front wings and the bonnet are made of carbon fibre-reinforced plastic (CFRP), the rear window is made of lightweight glass, and bi-xenon lightweight headlights — without a headlight cleaning system — save further weight. Some insulating material has been eliminated, too, and the privacy panel on the luggage compartment has been left off altogether. The interior is fitted with lightweight carpets. And naturally, no RS model is complete without lightweight door panel trim with textile pull loops and nets for storage compartments.
The bigger brake discs add weight to the car, but the Porsche 718 Cayman GT4 RS still weighs 35 kg less than the GT4. With the optional Weissach Package, the weight of the GT4 RS can be reduced even further. If, for example, the customer also orders the 20-inch forged magnesium wheels, the unsprung mass is reduced by a further 10 kg. Externally, the Weissach Package can be recognised by its use of carbon-weave finish on the bonnet, side air intakes and surrounding trim , the rear wing, the door mirror covers and the Porsche logo on the rear window. In addition, the tailpipes of the stainless steel sports exhaust system are made of titanium. The optional titanium cage is also approximately six kilograms lighter than its steel counterpart.
Individual colours grounded in Porsche history
Nine standard colours are available for the body of the new 718 Cayman GT4 RS: White, Black, Guards Red and Racing Yellow as solid colours; and Carrara White Metallic, Gentian Blue Metallic, GT Silver Metallic, Arctic Grey and Shark Blue as special colours. Buyers of the optional Weissach Package can also select unique paint finishes to suit their particular tastes. In the Paint to Sample programme, Porsche Exclusive Manufaktur offers a palette of 115 pre-approved colours.
