Air enters your engine through one of two primary methods: naturally aspirated or forced induction (turbocharging/supercharging).
Naturally Aspirated Engines
In a naturally aspirated engine, the process relies on atmospheric pressure and the engine's own mechanics:
- Piston Movement: As the piston moves down within the cylinder on the intake stroke, it creates a vacuum.
- Intake Manifold: This vacuum draws air through the air filter, into the intake manifold, and then into the cylinder via the intake valve(s). The intake manifold is designed to distribute the air evenly to each cylinder.
- Atmospheric Pressure: Ultimately, atmospheric pressure pushes the air into the vacuum created by the descending piston.
Forced Induction (Turbocharged/Supercharged Engines)
Forced induction engines use a compressor to force more air into the cylinders than a naturally aspirated engine could achieve. This results in a more powerful combustion.
- Turbochargers: Turbochargers are powered by exhaust gases. These gases spin a turbine, which in turn spins a compressor. The compressor forces air into the engine.
- Superchargers: Superchargers are mechanically driven by the engine, typically via a belt connected to the crankshaft. They also compress air and force it into the engine.
In both turbocharged and supercharged engines:
- Compressed Air: The compressor increases the air pressure before it enters the intake manifold.
- Intercooler (Optional): Often, the compressed air is cooled by an intercooler before it enters the engine. Cooling the air increases its density, allowing even more air to enter the cylinders.
- Increased Power: By forcing more air into the engine, more fuel can be burned, leading to a significant increase in power output.
In summary, air enters the engine either by being drawn in by vacuum (naturally aspirated) or forced in by a compressor (turbocharged/supercharged).
