A turbocharger is basically an air pump. Hot exhaust gases leaving the engine after combustion are routed directly to the turbine wheel side of the turbocharger to make it rotate. That turbine wheel is connected by a shaft to a compressor wheel. As the turbine wheel spins faster and faster, it causes the compressor wheel to also spin quickly. The rotation of the compressor wheel pulls in ambient air and compresses it before pumping it into the engine's chambers.

Even though the basic principal behind turbo charging is fairly simple, a turbocharger is a very complex piece of machinery. Not only must the components within the turbocharger itself be precisely coordinated, the turbocharger and the engine it services must also be exactly matched. If they're not, engine inefficiency and even damage can result. That's why it's important to follow correct installation, operating and preventative maintenance procedures.