The development of heavy duty engines is driven by customer as well as legal demands. To find the best compromise between low gaseous and particulate emissions with lowest fuel consumption and high reliability MAN Truck & Bus in cooperation with Honeywell developed a Two Stage turbo charging system for the D26 launched in 2009.
This paper describes the evolution of the D26 engine up to the present challenging emission legislation. The benefits of a Two Stage system compared to a Single Stage are discussed. Finally a detailed description of the turbo charger development such as matching challenges, aero selection and test bench work as well as special features of the latest evolution are part of the paper.