What exactly is VTEC?
VTEC Stands for Variable Timing Electronic Control, its basically giving the engine two different camshafts. On the lower end RPM's the engine has a camshaft for more torque, when it reaches past 4500 rpm the use of a different cam lope gives the engine more lift and duration for more high end power. The changes in pitch and the extra punch really gets you going when you stomp on the pedal.
The physics behind heat engines are determined by the change in heat Work out = Qh-Qc
and the efficiency is n=workout/Qh