Integrated Exhaust Manifold Cylinder Head Design Methodology for RDE in Gasoline Engine Application

In recent years, worldwide automotive manufacturers have been continuously working in the research of suitable technical solutions to meet upcoming stringent Real Driving Emission (RDE) and Corporate Average Fuel Economy (CAFÉ) targets, as set by international regulatory authorities. Many technologies have been already developed, or are currently under study by automotive manufacturer for gasoline engines, to meet legislated targets.

In-line with the above objective, there are many technologies available in the market to expand lambda 1 (λ=1) region by reducing fuel enrichment at high load-high revolutions per minute (RPM) by reducing exhaust gas temperature (for catalyst protection) for RDE regulation [1]. Integrated Exhaust Manifold (IEM) is the key technology for the Internal Combustion (IC) for the subjected matter as catalyst durability protection is done by reducing exhaust gas temperatures instead of injecting excess fuel for cooling catalyst. Additionally, this technology also helps in cost saving due to reduced parts count, in engine weight reduction, improve the response and increase fuel economy during the cold start stage of Modified Indian Driving Cycle (MIDC) and Worldwide harmonized Light vehicles Test Cycles (WLTC) by faster warm-up of coolant in cold stage and also fuel enrichment reduction (reduced fueling requirement) in high-speed regions of these cycles as shown in Figure 1.