A turbocharger, often called a turbo, is a small radial fan pump pushed by the energy of the exhaust gases of an engine used to boost intake manifold pressure. A turbo consists of a turbine and a compressor on the same shaft.  It changes the high temperature energy from the exhaust to power, forcing  the turbine and compressor to spin, compressing ambient air to the air intake manifold of the engine to a greater pressure, leading to a larger volume of air going in each cylinder. In some cases, compressed air is routed through an intercooler prior to entry of the intake manifold to cool the intake air for higher performance.

The object of a turbo is the same as a supercharger, to improve upon the efficiency of an engine by resolving one of its central limitations. A naturally aspirated automobile engine employs merely the downwards stroke of a piston to produce an area of low pressure in order to draw in air to the cylinder through the intake valves. Since the pressure in the atmosphere is no more than about 14.7 psi., there will ultimately be a limitation to the pressure difference over the intake valves and therefore the quantity of air flow going in the combustion chamber.  Because the turbo increases the pressure at the place where air is coming in the cylinder, a larger volume of air (oxygen) will be thrust inwards as the inlet manifold pressure increases. The added oxygen makes it feasible to supply further fuel, increasing the power and torque of the engine by using exhaust gases to drive the turbo.

Because the pressure in the cylinder must not go excessively high to avoid detonation and physical damage, the intake pressure must be restricted by controlling the rotational velocity of the turbo. This controlled operation is executed by use of a wastegate, which expels some of the exhaust flow away from the exhaust turbine of the turbo. This operation controls the shaft velocity of the turbo and governs air pressure in the intake manifold.

A great way to boost the performance of your naturally aspirated auto engine is to add a bolt on turbo kit. To gain more performance add an intercooler to cool the intake air.  There are a variety of turbo kits and intercoolers available.

Basic components and workings:

• Turbine and Compressor on a common shaft (turbo).
• Wastegate used to reduce pressure at the turbo and control intake manifold pressure.
• The turbo uses the exhaust to turn the turbine and compressor.
• The turbo compresses air to the intake manifold.
• Improves the efficiency of the engine creating more HP.
• Intercooler - performance upgrade to cool the intake air.