Substantial developments in automotive technology have led to the recent explosion in the availability of high-performance vehicles. One of the most important components of internal combustion engines for reducing fuel consumption and exhaust emissions. Exhaust back
pressure, a critical engine characteristic regulates the amount of internal exhaust gas trapped in the cylinder, affecting emissions and engine performance. The present work is focused on improving the performance of a multipoint sequential fuel injection engine by reducing the back pressure. The performance tests were carried out on a Hyundai i10 engine (1200 cc, multi-cylinder, 3000 rpm maximum speed). This study includes introducing fresh jet air at
various flow rates into the exhaust system to reduce the concentration of exhaust gas contaminants and provide the desired backpressure while accounting for changes in engine speed. The effect of backpressure on various engine performance parameters at different engine speed conditions has been analyzed. It is inferred from the present study that at 2000 engine rpm, the temperature of exhaust gas drops between 50oC and 90°C and there is a marginal increase in the volumetric efficiency from 4.5 to 6.25%. The engine power increased about 6 to 8.2% at this operating condition.