Forced Induction

Air. Fuel. Spark. Take one away from your car and you’re going nowhere fast. Increase one, air for example, and things get interesting. More air equals more power — the very principle behind forced induction. By compressing intake air prior to feeding it into the combustion chamber, forced induction squeezes more air in, along with a correspondingly greater amount of fuel. This results in bigger booms. Bigger booms equal faster, more powerful rotations at the crankshaft. In terms of horsepower and torque this is a good thing: forced induction engines will always up the ante over their naturally aspirated equivalents.

Two systems, supercharging and turbocharging, make this all happen. They differ chiefly in how they generate boost: where a turbocharger is spun by exhaust gases, a supercharger is powered by a pulley via the crankshaft. But before we examine their differences, discuss why they aren’t used everywhere and try to figure out if one is better than the other, let’s take a look at some boosting basics that apply to both systems.