Abstract
This paper presents turbocharged CNGDI engine performance under different fuel injection timing. The experiment was conducted on a 1.6 L, four stroke, four cylinders SI engine with compression ratio of 14:1. The effect of injection timing on engine output performance was investigated by varying the start of injection (SOT) timings from 300 bTDC to 120 bTDC. The engine was tested at wide open throttle (WOT) and speed ranging from 1000 to 4000 rpm. With turbocharging system, stratified charged combustion strategies (late injection timing) gives better torque performance at lower engine speed of 1000 to 2000 rpm. However, at higher engine speed of 2000 to 4000 rpm, homogeneous mixture strategies (optimal injection timing) resulted greater torque performance than late injection timing due to enough time available for air-fuel mixture preparation.