appreciated that in effecting such opening or closing of the apparatus outlets 58 and 62 it is not always the same aperture 108 or 110 that will open through each particular outlet in use when the engine 10 is running spent gases are exhausted from the cylinder 12 during the exhaust cycle via the exhaust port 18 when the exhaust valve 20 is open these gases travel along the exhaust manifold 40 to the scroll housing 30 where they drive the turbine wheel 28 in rotation before being exhausted to atmosphere via the exhaust opening 46 the turbine wheel 28 by way of the shaft 36 rotates the compressor fan wheel 32 which in turn draws in air through the manifold inlet 52 into the scroll housing 34 via the compressor inlet 48 the fan wheel 32 then forces this air under compression via the compressor outlet 38 and the inlet piping 42 to the inlet manifold 41 from the inlet manifold 41 the compressed air together with fuel such as petrol is forced into the cylinder 12 via the inlet port 14 during the induction cycle when the inlet valve 16 is open the manner in which fuel is mixed with the air will be understood by those skilled in the art and is not described further as will be understood by those skilled in the art the compression of the air by the compressor fan wheel 32 and the resultant pressure with which the air is forced into the cylinder 12 provides for significantly greater volumetric efficiency than would have been the case in the absence of the turbocharger 26 with resultant enhanced performance of the engine 10 and the motor vehicle it will also be appreciated by those skilled in the art that for a fuel.