Originally Posted by 70GS455

Here it is graphically. This is from a single dyno pull, with torque and hp in each gear calculated from the one-gear data.

The solid lines represent torque in each gear. The dashed lines are hp in each gear. You get the same answer using either one.

The important thing to take away from this is that for minimum elapsed time, you must maximize hp (and tq) at all times.