Plain English Meaning

A device that uses the engine's own exhaust to spin a small fan, which packs more air into the engine. This lets the engine keep making strong power even at high altitudes where the air is thin.

Full Definition

An exhaust-driven air compressor fitted to a piston engine that uses energy from the engine's exhaust gases to spin a turbine, which in turn drives a compressor that forces a denser charge of air into the engine's induction system. This restores or increases manifold pressure at altitude, allowing the engine to maintain rated power where the surrounding air is too thin to support it naturally.

Context Anchor

Seen in aircraft engine , , -altitude , and manifold pressure discussions.