NVH Aspects of a Downsized Turbocharged Gasoline Powertrain with Direct Injection

The European Automotive Industry has committed to reduce the emissions. In order to comply with these CO₂ requirements, the introduction of fuel efficient technologies is absolutely mandatory. Therefore ‘Downsizing’ is a known way to reduce part load fuel consumption by combining significant displacement reduction with turbocharging to achieve equivalent torque and power levels [1]. To fulfill these demands, an inline gasoline three cylinder powertrain with turbocharged direct injection (SCi Turbo) has been developed. The challenge during the development of such a powertrain is that no degradation on customer demands regarding the key criteria, among others driveability and NVH, is allowed.

This paper will show the powertrain components that are affected most by these NVH attributes; this concerns mainly the engine and the power conversion system. The results, achieved by CAE and Measurements, show clearly that a potential deterioration of the different noise sources can be more than compensated by the introduction of certain countermeasures.