The forthcoming Porsche 718 Cayman GT4 RS has been spotted running tests once again, this time at the venerable Nurburgring Nordschleife circuit in Germany. This will build upon the specification and as a result, performance of the 718 Cayman GT4, which arrived with a 4.0 litre, naturally aspirated flat-six engine producing 420 PS at 7,600 rpm and 420 Nm of torque between 5,000 rpm and 6,800 rpm.

Drive will go to the rear wheels, as is typical for a GT department Porsche, though here the GT4 RS can be seen through the windscreen to sport shift paddles behind its steering wheel – this will be for a dual-clutch PDK transmission in place of the six-speed manual in the ‘standard’ GT4.

The engine in the GT4 RS is expected to output in the region of 450 PS, which is a comfortable middle ground between the GT4 and the 911 GT3 which sports 500 PS from a similarly-sized engine. This should be a development of the 9A2 Evo engine, as head of Porsche GT car Andreas Preuninger has said before that the 911 GT3 engine would not fit into the mid-engined Cayman.

Chassis revisions will likely be uprated springs and dampers relative to the Cayman GT4 in order to handle higher-speed track driving, with the larger rear wing offering greater downforce on the GT4 RS. Further aero revisions feature on the bonnet with NACA ducts, while the rear side windows have been replaced with additional intakes on top of the existing side scoops.

Though the Cayman GT4 and its open-topped sibling, the Boxster Spyder has been offered from launch exclusively with manual transmission, the duo will have the PDK dual-clutch gearbox available to buyers as well by the end of this year, with the Cayman GT4 RS debut likely to be around the same time.