Upcoming flagship variant edges closer to production debut.

Spy photographers have captured the Porsche 718 Cayman GT4 again this week, ahead of an anticipated reveal later this year.

The prototype was spied alongside the related 718 Boxster Spyder development vehicle, wearing next to no camouflage as per the most recent sighting.

It's believed the 718 Cayman GT4 and 718 Boxster Spyder will become the flagship versions of Porsche's smallest sports cars, packing more grunt and enhanced aerodynamics to their lesser brethren for improved performance on the track.

Additionally, the GT4 and Spyder will likely divert from the current 718 range's move to downsized turbocharged engines, instead opting for a detuned version of the 4.0-litre flat six that currently does service in the 911 GT3 – which makes 368kW of power and 460Nm of torque in that model.

Drive will be sent to the rear wheels, and it's expected both a six-speed manual and seven-speed PDK dual-clutch automatic transmissions will be available.

The previous-generation Cayman GT4 was powered by a 283kW.420Nm 3.8-litre flat six, capable of hitting triple figures in 4.4 seconds. We're expecting the new model will edge closer to the 4.0-second mark, even in the high threes – considering the 718 GTS does the benchmark sprint in 4.1 seconds, you'd think Porsche would want the flagship to be quicker.

In addition to the unique engine, the GT4 will get the more focused bodykit you see here, a fixed rear wing, and an upgraded wheel and brake package with added grip and stopping power.

As we've noted previously, the tailpipes on the GT4 prototype appear to be wider set than the centrally-mounted units of the current crop of four-cylinder 718 models.

In terms of timing, it's believed the 718 Cayman GT4, and potentially the 718 Boxster Spyder, will make their debut at the Paris motor show in October.

Stay tuned to CarAdvice for all the latest, and head to the galleries section for more images.