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Air from the compressor is routed through an air-to-air intercooler before it enters the air-box. Because of the increased horsepower level, larger fuel injectors are used to supply the increased level of fuel. Compression ratio was lowered from 11:1 on the standard 900, to 9.1:1 on the turbo engine. This is usual on turbo applications not only because of the extra turbo pressure, but also because the increased combustion chamber volume makes room for more charge mass. This required a redesigned piston with a dished top crown, which not only increases the volume but also provides a deeper and more efficient combustion chamber. This design is very close to those considered optimum in the World War II Rolls Royce supercharged Merlin and Griffin fighter plane engines.
The pistons are also strengthened and cooled on the underside by oil from strategically placed nozzles. This is basically technology now found in uber-expensive Formula One race-car engines. Not only is the piston stronger, but the connecting rods are also reinforced as well as the crankshaft with a wider rod-bearing journal. To back all the extra power up with reliability, the head is revised for extra cooling and a larger water pump provides more cooling fluid. The oil circuit is now fed by both a larger oil scavenging pump and a larger higher pressure oil supply pump.