Development of a Low Emission Retrofit Kit for Urban Bus Engines

This paper describes the development of an emissions upgrade kit for the DDC 6V-92TA MUI bus engine manufactured by the Detroit Diesel Corporation (DDC). It incorporates three components: a base engine upgrade kit, a diesel oxidation catalyst and an electric demand turbocharger. A particulate matter level of 0.09 g/hp-hour has been demonstrated and certification is currently being sought at the 0.1 g/hp-hour level under the US EPA's Urban Bus Rebuild/Retrofit Program.