Home » 2015 Porsche 911 GT3 R vs. GT3 Cup vs. GT3 RSR – Visual and Specs Comparison » 2015 Porsche 991 GT3 Cup 4 2015 Porsche 991 GT3 Cup 4 Home » 2015 Porsche 911 GT3 R vs. GT3 Cup vs. GT3 RSR – Visual and Specs Comparison » 2015 Porsche 991 GT3 Cup 4