Originally Posted by marts1
If you are using the same bike, same wieght, etc., twice the speed you will not get. Ratio's come into play here.
Marts1 is correct,
and add to his words, torque, advertised horsepower verses actual, combustion effeciency, etc etc. You cannot simply take a given horsepower, add a value to it and compute speed. Many factors come into play before an actual figure could be derived. That being said and to give you some answer, you can generally always expect an increase in speed by adding horsepower but its just not simple addition. Good luck, and ride safe at any speed.