To ensure that the engine’s power is best transferred to the road, the chassis engineers who worked on the new Porsche 718 Cayman GT4 RS have regularly looked to racing technology. The main development objective was to provide the driver with a high level of steering precision, combined with excellent grip in the corners. In combination with the near-instantaneous throttle response of the 500 PS (368 kW) engine, this results in exceptional driving qualities that give the driver a high level of confidence in the car and a lot of driving pleasure.
The front axle of the 718 Cayman GT4 RS was taken from the 911 GT3 RS (991.2 generation) and is also used in the 718 Cayman GT4. The classic MacPherson strut-type axle is additionally equipped with helper springs that keep the main springs under tension when they are deflected. The main spring maintains its original tension even under maximum load. This benefits the vehicle’s controllability during particularly dynamic driving.
Thirty millimetres lower, wider track, more camber
Compared to the 718 Cayman, the body has been lowered by 30 mm. In addition, the front track is six millimetres wider and the rear track is eight mm wider than on the 718 Cayman GT4, which reduces the vehicle’s lateral inclination. At the same time, the rear axle camber was increased by a quarter of a degree, which means that the rear tyres transfer greater cornering forces. The result is even greater predictability when taking corners at speed.
Ball joints at all connection points of the chassis ensure a particularly tight connection to the body, which results in very precise and direct handling.
With adjustable PASM chassis as standardIn addition, the track-focused chassis of the new top-of-the-range model in the 718 series features RS-specific spring rates and damper tuning. The chassis can also be adjusted for circuit driving. The tracking, camber and anti-roll bars can be individually adjusted to the driver's preferences and the circuits characteristics for driving on the racetrack.
The GT4 RS is equipped with Porsche Active Suspension Management (PASM) and sports tuning as standard. This active damping system unites what is effectively two chassis in one. In Normal mode, the dampers operate in a more comfortable state of tune, but they automatically switch to a more athletic mode when the car is being driven dynamically. In Sport mode, on the other hand, firmer damper characteristics are directly activated, supporting an agile driving style. Sports tuning, which can additionally be switched on, results in even more tightly controlled damping and ensures even better performance on the circuit.
Porsche Torque Vectoring makes for more agile cornering
The heart of the driving assistance systems is the Porsche Stability Management (PSM), which also combines three electronic control systems in the 718 Cayman GT4 RS: the anti-lock braking system (ABS), Electronic Stability Control (ESC) and Traction Control (TC). As one would expect from an RS, these control systems intervene very sensitively and only when very close to the limit – drivers should not feel that control has been taken away from them, particularly when they’re on the racetrack. Porsche sets up its chassis so that it already combines the best possible performance with safe handling even without the use of electronic control systems. Therefore, if you want to drive without a safety net, you can switch off the systems in two stages (ABS excepted): ESC OFF gives the driver sole responsibility for cornering stability, and the ESC+TC OFF setting overrides traction control as well.
Porsche Torque Vectoring (PTV) is also available as standard for the GT4 RS as a further driving dynamics system. PTV works with an electronically triggered brake intervention on the rear wheels; in addition to this, the 718 Cayman GT4 RS has a mechanical limited-slip differential with RS-specific locking values (traction 30 per cent/overrun 37 per cent). In practice, PTV, which cannot be switched off, works in such a way that, in dynamic driving, the inside rear wheel is braked slightly as soon as the driver turns the steering wheel. This means that additional power is delivered to the rear outside wheel and, in a corner, gives the car a steering impulse in the direction in which the steering wheel is already turned. This extra steering effect leads to an even-more agile and direct driving experience and makes cornering faster and safer at the same time.
Lift system protects against contact with speed bumps
For the first time in the 718 series, Porsche is offering an optional front axle lift system for the 718 Cayman GT4 RS. At the touch of a button, the ride height is hydraulically raised by approximately 30 mm at the front axle. The ground clearance at the front spoiler lip is therefore increased by around 40 mm, which makes it easier for the driver of the RS to cope with speed bumps, garage entrances or multi-storey car park ramps without contact. The lift system also reduces the risk of damage caused by kerb edges. It can be used at speeds of up to 60 km/h and, of course, when stationary – but the driver’s door must remain closed.
The new Porsche 718 Cayman GT4 RS uses aluminium monobloc fixed-calliper brakes with six pistons at the front and four pistons at the rear. As the housing of the monobloc brake calliper is also the brake carrier, brake pistons are located on both sides of the brake discs. This results in a high level of rigidity, which ensures very good pressure point behaviour even under high loads.
Enlarged brake system with additional ventilation
The cast-iron/aluminium composite brake discs have a diameter of 408 mm at the front. They are therefore 28 mm larger than those on the 718 Cayman GT4. The brake cooling system has also been adapted to the increased performance: two NACA air intakes in the bonnet direct air flow to the front wheels. These air ducts mean that the brakes can withstand even a continuous load on the racetrack without any problems. On the rear axle, deceleration is provided by the familiar brake discs from the GT3, which have a 380 mm diameter.
As on the current 992-generation 911 GT3, the brake discs on the 718 Cayman GT4 RS are no longer drilled, but dimpled. The dimpling process creates small dents on the brake disc, which, just like the bore, helps clean the copper-free brake pads. Another advantage of the countersunk brake disc is its even higher temperature resistance.
Optional ceramic brakes and magnesium wheels
The brake callipers of the GT4 RS have a red paint finish as standard; they are optionally available in High-Gloss Black. The Porsche Ceramic Composite Brake (PCCB) system is also available as an option, recognisable by its distinctive yellow brake callipers. On request, these are also available in High-Gloss Black. Unlike the cast iron/aluminium composite brakes, the discs of the PCCB system are still drilled, but are a bit larger: 410 mm at the front, 390 mm at the rear. Ceramic brake discs guarantee the highest level of fade resistance under heavy loads, but their decisive advantage lies in their weight: PCCB discs only weigh about half as much as cast-iron discs. This reduces unsprung mass and increases both driving comfort and agility.
The 718 GT4 RS has the ideal wheel size, just right to fill its wheel arches: 20-inch wheels (8.5 J x 20 ET61 at front, 11 J x 20 ET50 at rear), made using aluminium forging technology. The wheels are painted Dark Silver (satin finish) as standard and for the first time in the 718 series feature a centre-lock nut in Black with an ‘RS’ logo in Silver, also as standard. In addition, attractive special paint finishes are available as options: Indigo Blue (satin finish), Neodyme (satin finish), Black (satin finish) and classic Silver. One special highlight is the optional paint finish in Black (satin finish) with a rim edge painted in Racing Yellow. In conjunction with the optional Weissach package, 20-inch forged magnesium wheels are also available, which reduce a further 10 kilograms of unsprung and rotating mass on the vehicle. An exclusive version in White Gold Metallic is also available for this variant, but the combination of Black and Racing Yellow is not included in the Weissach package.
Tyre pressure monitoring takes into account conditions on the racetrack
Road-approved sports tyres fitted to the GT4 RS in the same dimension as on the GT4 ensure the necessary grip: 245/35 ZR 20 at the front and 295/30 ZR 20 at the rear.
Drivers who plan on spending most of their time on track can also purchase special track-focused tyres from their Porsche dealer. Their technology is based on that of the standard sports tyres, but uses a modified rubber compound and an optimised profile. This makes them primarily suited to use on racing circuits; they offer even better performance on a dry race track, with certain performance losses in wet conditions. Nevertheless, the tyres are also road-approved.
The standard Tyre Pressure Monitoring (TPM) system is also optimised for use on track. It not only warns against gradual or sudden pressure loss, but also takes particular account of pressure and temperature.
