Big difference between Vy and Vx as Vx is typically less than 10 knots above power off stall. In addition if you are at Vx you will be typically close to the ground and in a steep nose up attitude. When you try the test try it at altitude and assume the engine has failed at 100 AGL. I think you will be surprised at how far the nose has to go down and how fast the 100 feet disappears .....