| dc.description.abstract | Fuel efficiency and engine performance are crucial aspects in the development of energy-efficient vehicles. This study aims to analyze the effect of varying the number of holes in the magic ring on the engine performance of the Urban Team Horas car. The magic ring is a component installed in the exhaust system to enhance combustion efficiency by controlling exhaust back pressure. Experiments were conducted on a Yanmar L40AE-S diesel engine used in the Urban Team Horas USU vehicle. The tested magic ring variations consisted of 6, 8, and 10 holes. Performance testing was carried out using a dynamometer to measure torque, power, specific fuel consumption (SFC), and thermal efficiency, while a gas analyzer was used to assess exhaust emissions. The results showed that the magic ring with 10 holes produced the highest torque of 13 Nm at 1000 rpm, while the highest power output of 1.9 kW was achieved by the 8-hole magic ring at 2000 rpm. The lowest specific fuel consumption (SFC) was recorded at 234.21 g/kWh by the 8-hole magic ring at 2000 rpm, and the highest thermal efficiency was found in the 6-hole magic ring, reaching 28.77% at 1900 rpm. Emission testing indicated that the 8-hole magic ring provided the most optimal combustion results, with the lowest CO levels in the 1400-2600 rpm range. Thus, the variation in magic ring holes significantly affects engine performance and efficiency. The 8-hole magic ring offers the best balance between power, fuel efficiency, and exhaust emissions. | en_US |
