Normally Aspirated v Forced Induction

Naturally Aspirated

A naturally aspirated “Breathing” engine is less powerful than an equivalent capacity turbo engine.

Naturally aspirated refers to an internal combustion engine normally powered by petrol or diesel that is neither turbocharged nor supercharged.

Most modern diesel vehicles use turbochargers, because naturally aspirated engines cannot usually offer suitable power-to-weight ratios for today’s customers.

Commonly used forced induction systems are turbochargers and superchargers, the exhaust gases drive turbochargers, and superchargers are driven by a gear train or belt connected to the crankshaft.

Superchargers

A supercharger is an air compressor used to force more oxygen rich air into the combustion chamber, the additional mass of oxygen rich air improves volumetric efficiency of the engine

Volumetric efficiency is a ratio of the volume of fuel and air that enters the cylinder during induction to the actual capacity of the cylinder under static conditions.

Engines with higher volumetric efficiency will generally be able to run at higher RPM, and power, as they lose less power moving air in and out of the engine.

The higher the volumetric efficiency of an engine, the more fuel it can burn in a given cycle, thereby producing more power.

Forced Induction