In 2015, PROsport Racing developed the Porsche Cayman Pro4. The in-house design based on the Cayman was developed by the team from Wiesemscheid for the GT4 class. In 2016, former DTM driver Peter Terting and veteran Jörg Viebahn won the title in the Pro class of the GT4 European Series. After the 2018 season, the car's use in the SRO sector ended, but after a few appearances on the Nordschleife, the car still competed in the then DTM Trophy in 2020 and 2021.

After the races, the team kept the Porsche for purely emotional reasons. "But over time, the question arose as to whether we could bring the car up to the level of a current GT4 car," explains team principal Chris Esser. "This developed into an employee project of our young team members, who, if there was time, developed the vehicle over different stages in winter."

First, the team installed a new sequential transmission, with paddleshift. This alone resulted in a weight saving of 40 kilograms compared to the original PDK transmission, which was installed in the Cayman Pro4 in 2015.

As a new engine, PROsport Racing installed the 3.8l engine of a Porsche 911 GT3 Cup (generation 991.1), which develops 460 hp. The traction control and ABS system of the one-make cup vehicle were also installed – the original vehicle did not yet have these driving aids installed, which significantly improves drivability.

The aerodynamics of the vehicle have also been refined, especially the larger rear spoiler catches the eye. A new front splitter also helps the Cayman Pro4 to develop more downforce. The Porsche Cayman Pro4 will also drive on wider wheels, for which the rear axle has also been widened.

"The project was very important for our employees, as many mechanics in modern motorsport are no longer really familiar with points such as vehicle development, as a large part of current motorsport are customer sports cars. I was very pleased to see how they were absorbed in the project and independently worked out which changes would best suit the vehicle. In total, we have invested around €50,000 in the further development of the Cayman Pro4. When I look at the price at which we developed the car in 2015 and have now developed it further, it shows me very clearly how expensive GT4 racing has become in the meantime and in the end the cars are only slowed down again by the Balance of Performance. I find it remarkable that we could still compete competitively in various racing series with our ten-year-old car, while we are currently no longer allowed to compete in the GT4 European Series with our six-year-old Aston Martin Vantage GT4," Esser continues.

Most recently, the team completed a first day of testing with the revised Porsche Cayman Pro4 on the Nürburgring GP circuit. "On the same test day, in addition to the Cayman Pro4, we were on the road with our Aston Martin Vantage GT4s. The same driver was about two seconds faster with the Porsche than with the Aston Martin. The times were about halfway between GT4 times and the lap times of the current Porsche 911 GT3 Cup, which were also tested. That makes us very confident. We suspect that we will be able to drive lap times of 8:20 – 8:25 minutes on the NLS version of the Nürburgring-Nordschleife!", Chris Esser concludes.

The Porsche Cayman Pro4 will still take part in Friday testing in the course of the 2025 season as part of the Nürburgring Endurance Series. As soon as these are successful, PROsport Racing will also start racing with the car. The team from Wiesemscheid would determine the drivers at short notice.

At the KW 6h ADAC Ruhr-Pokal races, PROsport Racing will compete with the usual Aston Martin Vantage GT4 and the Aston Martin Vantage GT8R. The Aston Martin Vantage GT4 will be driven by Jörg Viebahn, Michel Albers and ADAC GT Masters race winner Benjamin Hites. The father-and-son team Guido and Maxime Dumarey will drive the Aston Martin Vantage GT8R in the SP8T class.