How does the Turbo work?
TURBINE
    A turbine wheel is driven by the otherwise 'waste' exhaust gases. The turbine is connected to a compressor wheel and the whole assembly rotates at speeds up to 230,000 rpm.

COMPRESSOR
    Ambient air is drawn into the turbo via an air filter, then, as it passes over the compressor wheel it accelerates up to very high speed.

    Once past the compressor wheel it passes through a 'diffuser' which is formed between the face of the backplate (or centre housing) and the machined face of the compressor housing.

As it passes through this area the air moving at high speed slows down and this continues as it passes though the 'volute' of the compressor housing (shaped like a snail's shell!). This turns the Kinetic energy of the moving air into high pressure air.

Turbocharger Gas & Air Flow

Turbocharger Gas & Air Flow - On Engine