Turbocharging is a common and simple method to utilize the exhaust heat of an internal combustion engine. However, conventional turbocharging exhibits the drawback of exhaust gas backpressure and thus increased residual gas mass in the cylinder. A promising concept to increase optimum efficiency is found in the TwinAV concept, which assigns divided exhaust valve cam timing and exhaust manifold configuration. This concept is hypothesized to reduce the static backpressure in the gas exchange loop and the residual exhaust gas amount in the gas exchange phase. In this article, a 1D simulation model was adapted to an existing 4-cylinder gasoline TC engine. Subsequently, the engine concept was applied to this engine model, whereas the focus was to achieve an engine layout for the entire engine speed range applicable for use in passenger vehicles. The results were compared at the full RPM range. Also, a load variation was conducted and benchmarked. The found results show an additional specific fuel consumption benefit of 6.4%, which is partly achieved by the reduced static backpressure and partly a result of less knock sensitivity due to less remaining internal EGR, observed in an earlier CA50 and peak pressure position. Simulation results indicate benefits in the upper half of the engine map and a maximum benefit in a region around the engines’ sweet point. This is a conceptual simulation-based study; no experimental or transient validation has been conducted.
Gotter et al. (2026) studied this question.