In the early 1980s most of the worlds Formula One teams turbocharged their race cars for one major reason: more power from a smaller engine size and weight. Turbocharged cars offer more power, more speed and better handling than their rivals with conventional naturally aspirated engines. A turbocharged engine can provide good engine response with the reassurance of reliable reserves of power when you need it.
Ever since the introduction of diesel engines, the demand has always been for small engines capable of producing maximum power. Add to this the present environmental problems of lead pollution etc, plus the economics of the diesel engine user and you have an area in which the turbocharger can play a major part.
We have already given some reasons for turbocharging i.e. the power of an engine is controlled by the ratio of air to fuel. The size and weight of engines has become important; no-one wants to lose a large amount of the power from the engine simply to propel the excess weight down a road, or to have huge vehicles just to carry normal loads.
Under normal circumstances the addition of a turbocharger to a naturally aspirated engine will increase the power output by approximately 30%. Remember, this means basically the same size engine giving more power to be used by the operator. In the early days it was common practice to put a turbocharger onto a naturally aspirated engine, now turbocharged engines are designed to take into account the higher stress thermal and mechanical loadings placed on the engine and other ancillary parts by the turbocharger.