Performance Development of the Holset Variable Geometry Turbocharger

Variable geometry turbochargers offer engine designers the option of controlled charge air pressure but at the expense of increased complexity. A novel form of variable geometry turbine has been developed that has many advantages. The design and testing of several variations of a basic theme is described and the development of the most promising is followed. This has produced a simple, durable and cost effective design with performance better than that of more complex alternatives.