Engineers at Porsche’s motorsport division have liberated an extra 79bhp and 15lb ft from the Cayman’s naturally aspirated 4.0-litre flat six, which redlines at 9000rpm. That takes the total outputs to 493bhp and 332lb ft for a 0-62mph time of just 3.4sec and a top speed of 196mph.
Power is sent to the rear axle through a seven-speed PDK automatic gearbox, which shifts “at lightning speed”, according to Porsche.
Weight has been slashed by swapping the bonnet and front wings for carbonfibre-reinforced plastic items, installing lightweight carpets, replacing the door handles with pull straps, reducing the amount of insulation and installing a lighter rear windscreen. These measures combine with the engine modifications to give a power-to-weight ratio of 348bhp per tonne.
Porsche has also further optimised the GT4’s aerodynamics. A swan-necked rear wing based on that used by the 911 RSR GT racer, new air vents and adjustable front diffuser – together with a 30mm drop in ride height compared with the standard Cayman – are said to increase downforce by as much as 10% over the GT4, and in track-oriented Performance mode that climbs to 60%.
The rear windows, meanwhile, have been swapped for air intakes for improved airflow to the engine, a by-product of which is a “thrilling intake noise right next to the occupant’s ears”.
There is also a bespoke shock absorber set-up and a specific tune for the spring and anti-roll bar rates to give keener handling.
An optional Weissach package, as seen here, brings a carbon-weave finish for various exterior trim items, aluminium exhaust tips, a titanium roll-cage and bespoke 20in forged aluminium or magnesium wheels.
The 718 Cayman GT4 RS is on sale now priced from £108,370, which is £31,840 more than the GT4. The first UK cars are expected to be delivered in March 2022.
GT4 RS: How much quicker is it?
The new addition to Porsche’s hallowed RS line-up is a substantial 23.6sec quicker around the Nürburgring than the existing GT4, hinting at the effectiveness of the extensive mechanical and dynamic modifications.
In the final stage of testing, ex-racer and brand ambassador Jörg Bergmeister lapped the slightly shorter 12.8-mile Nordschleife circuit in an impressive 7min 4.51sec, while a 7min 9.3sec lap time around the full 12.9-mile circuit makes it very nearly as quick as the previous 911 GT3 RS.