Why would a car hesitate when eccelerating at higher speeds?

this has been a problem that has been going on from the beginning. the timing can not keep up with your foot. when you press the gas, the timing adjust to accommodate. G. M. has found a solution, VARIABLE TIMING. it adjust on the fly, it is hydraulic controlled, using the motor oil. it is not easy to work on, needs special tools and training, but it works great. this feature it part of the new VORTEC ENGINE.