The new Porsche 911 GT4 R race car has been revealed as the successor to the discontinued 718 Cayman GT4 RS Clubsport.That makes it the first 911-based GT4-spec racer, and it's powered by a 4.0-liter flat-six that makes up to 513 horsepower and 346 pound-feet of torque. The 911 GT4 R will be sold in the United States for $375,000, and it will start competing in the 2027 motorsports season.