This is why it is important to have a powerband where maximum torque occurs at a lower rpm than the maximum horsepower peak. With good torque backup, the secondary helix feels an increase in torque as drag tries to pull the rpm down. This is where a lot of confusion starts, mainly because it is not easy to understand what the difference is between torque and horsepower, and there is a BIG difference. Torque is the result of the gas forces above the piston working on the crank arm and creating a momentum. This momentum force can be measured on the dyno brake and is usually given in foot-pounds.
Work is something different.
It is a question of how often in a given time period you can lift a certain weight. The more times you can lift a weight in a minute, the more work you produce. The same with an engine. Torque tells you how big a load you can lift, and the rpm tells you how often you can do it in a minute. The horsepower curve is a result of multiplying torque load with engine speed to find the optimum combination of load and speed that will produce the most work.