The influence of combined VVTsystems on polluting emissions and dynamic performance in SIE

One of the modern methods of reducing pollutantemissions and increasing dynamic performance is the implementation of distribution phase variation systems for both the intake valve and the exhaust valve, called combined VVT, applied over a wide range of engine operation regimes. The paper aims to highlight how such a solution leads to improved dynamic performance and reduced chemical pollution. Achieving this goal involved experimental investigations into a small class cars SIE. The variants of combined VVT (intake & exhaust), research methodology and an analysis of experimental results on a wide range of functional regimes are presented. It is concluded that such a solution can lead by implementation on engines to remarkable results both in terms of NOx reduction and in terms of dynamic performance (torque and power).