The waste exhaust gas from the engine are utilised to drive a turbine wheel. This is connected to the compressor wheel by a shaft. The compressor wheel sucks air from outside the vehicle through filters and then into the engine at speeds of up to 200,000rpm!
Instead of venting the exhaust gases through the exhaust pipe to atmosphere, the waste exhaust gas created by the engine is fed to the turbine exhaust wheel
The exhaust fumes hit the turbine blades spinning the shaft.
The exhaust fumes then exit the turbocharger and are sent through the exhaust system.
The turbine powers the air compressor at the front of the turbo. The air gathered is colder and denser than atmospheric air. The additional oxygen allows for the air and fuel mixture to burn more completely. This provides the engine with additional power.
Advancements in Turbocharger Technology:
Turbochargers offer many benefits but have a significant problem named turbo-lag. This is caused when the engine is not producing enough exhaust pressure to spin the turbine. The driver will notice a delay in throttle response until the exhaust can provide enough boost pressure to the turbo.
The e-turbo (electronic turbo) appears to address this issue by the use of an electric motor. This technology has filtered down from Formula One cars. Rather than wasting the exhaust energy through the waste-gate (valve that bypasses the turbo), the exhaust energy is instead harvested through a specially designed bearing assembly and stored in a battery. When the engine is at low rpm and the turbo has not spooled fully the generator reverses roles and supplies power to the turbo shaft. This completely eliminates turbo lag and provides instant acceleration.