You cannot exceed the speed of light as measured from ANY reference frame. This fact is the reason time dilation and constriction of length occur. These things prevent an outside observer from looking through the window of a spaceship traveling at C-1 and seeing the traveler throw a ball forward at +2 resulting in a ball speed of C-1+2=C+1. Your clock and measuring stick (both necessary for speed measurements) will be different than those in the spaceship. This will result in you observing that the ball is moving extremely slow through the spaceship while it looks perfectly normal to the traveller inside the ship. This means that the frisbee on top will be in a different time frame than you. No matter how many you stack, even if it's 20 all going at 30,000 rpm, you can never measure the top frisbee speed to be greater than C. In fact, you will never measure the top frisbee speed to even be equal to C because of the effects of time dilation and constriction of length, even if you could produce infinite energy to overcome the infinite mass involved.