In this research, different methods are developed to vary intake length. Various methods like ram effect tuning and geometric devices are researched in literature review to increase engine performance. Ricardo WAVE simulation software is used to simulate 4-cylinder engine. Main aim behind simulation is to study how induction manifold length tuning affects the inline 4-cylinder engine. Volkswagen cabriolet engine specifications are used to set parameters including stroke, bore, and clearance height etc. From simulation results, it is clear that by varying intake manifold length power and torque of the engine is increased, while fuel consumption is improved and therefore engine performance is improved.