Photo: Porsche Porsche has unveiled its new GT4 machine of choice, the 911 GT4 R, that will replace the 718 Cayman GT4 RS Clubsport beginning next year. The 911 GT4 R, which is largely based on the German manufacturer’s high-performing new Type-992.2 Porsche 911 Cup car, will allow drivers to begin in single-make series and progress through the Porsche Motorsport pyramid, up to GT3 competition, all on a single 911 platform. Powered by a 4.0 liter six-cylinder boxer engine that delivers up to 520 horsepower, the same powertrain found in the single-make car, the 911 GT4 R is expected to make its official race debut in January’s IMSA Michelin Pilot Challenge season-opener at Daytona International Speedway. It will be eligible in all series than run to the SRO GT4 technical regulations, including GT4 European Series, Pirelli GT4 America, among numerous others. Compared to the 718 Cayman, which has gone out of production as an internal combustion engined road-going model, th...