Priliyan Fadhil Nafi, Ibnu Siswanto, Ayu Sandra Dewi, Bambang Sulistyo, Purwanto
This study aims to determine the performance of the motorcycle engine before and after the velocity stack is installed and modified. Another objective of this study is to determine which size variation (55, 70, or 80 mm) is the most optimal in increasing torque and power based on the data seen from the dyno test results. The study/.y used an experimental method to identify the effect of the velocity stack modification on the engine's output. All the variations of the velocity stack used in this study are available in the market. Furthermore, the torque and power measurement of the vehicle using a dyno test machine was further analyzed using descriptive analysis. This experimental study uses a vehicle that has a K56A engine code to identify the variation effects of velocity stack on the engine's performance. From the tests carried out, the original velocity stack-producing engine output is 15.6 HP, while the maximum torque is 12.93 N/m. Velocity stack 55 mm produces a maximum torque of 13.16 N/m and a maximum Power of 17.2 HP. Velocity stack 70 mm produces a maximum torque of 13.51 N/m and a maximum power of 17.5 HP. Velocity stack 80 mm produces a maximum torque of 13.55 N/m and a maximum power of 17.2 HP. Hence, based on the results of the study, it can be suggested that the use of a velocity stack of 70 mm produces higher maximum power than other velocity stacks used in this study. While the uses velocity stack 80 mm generates higher maximum torque than the standard velocity stack, 55 or 70 mm. © 2025 Author(s).
Department of Mechanical and Automotive Engineering, Faculty of Vocational Studies, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia; Department of Automotive Engineering Education, Faculty of Engineering, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia
