A friend of mine has a 2015 R1 flashed with a Akra 3/4 exhaust. My bike is a 2016 ZX10R flashed with a two brothers 3/4. When we race the results are about the same. Although, when we race from lower speeds he always gets the jump on me and then I start walking past him. Another friend of mine has a 2016 R1, stock. And he cannot keep up with us. It is amazing the difference a cat delete and flash will make on these bikes.