Recently, a 2015 Porsche 911 GT3 RS prototype was spied during testing on the Nurburgring race track in Germany. According to our sources, the future Porsche 911 GT3 RS (2015) is powered by a 3.8-liter 6-cylinder engine that's going to put out more than 475 hp. Porsche is expected to reveal the new generation 911 GT3 RS in October at the Paris auto show.