The influence of injection pressure on the performance of a FIAT passenger car Diesel engine prototype equipped with a Common Rail Fuel Injection System has been investigated.
An increase of the injection pressure from 1300 up to 1500 bar, during this research, has permitted the assessment of the effect of this parameter on the maximum power and on the smoke emissions. The tests were performed at 4000 rpm, with an equal mass of injected fuel. The influence of the injection advance has also been taken into consideration during this experimental analysis.
The in-cylinder pressure was first detected and recorded, together with the brake torque and emissions; the in-cylinder pressure was then used for the determination of the principal combustion characteristics, on the basis of the heat release analysis.
Finally, higher injection pressure could be used as an effective parameter to increase the maximum power angular speed. This choice can be made on the basis of vehicle driveability considerations.