Abstract
Downsizing in combination with turbocharging represents the main technology trend for meeting climate relevant CO2 emission standards in gasoline engine applications. Extended levels of downsizing involve increasing degrees of pulse charging. Separation of cylinder blow downs, either with double entry turbines, valve train variability or firing distance, is the key for achieving enhanced full load and transient performance targets in highly boosted passenger car engines.
As a consequence, the design and matching process has to consider not only the performance targets of the engine, but the engine air path as well as the valve train in the design and matching process. This paper demonstrates the design and matching process of the entire boosting system in an early development phase. In a first step, engine performance will be translated into performance targets of the turbo-machine and subsequently into design parameters of the wheels and housings. This allows the turbocharger to be designed exactly to specific engine requirements in a fast and cost optimized development process.
KEYWORDS Turbocharger matching, downsizing, transient response