Search Results

The purpose of this research is to implement the variable intake manifold on a Formula Student racecar to achieve a lower overall Autocross lap time. A previous version of the linearly adjustable variable intake manifold prototype was able to deliver an improved engine performance in the form of wider range of engine RPM with high torque, but its dimension did not conform to the FSAE regulation. This research focuses on developing a physically compact rotary variable intake system to achieve a favorable characteristic while conforming to the FSAE rules. The engine is expected to perform better than the previous one by comparing the range of engine RPM which produces torque greater than 48.47 N-m, representing 90% of maximum torque or our 2015 car with a conventional intake system. The optimum runner length is determined using the pressure wave tuning method.

This study focuses on achieving a lower overall lap time at SAE Formula Student competition through a modification to the standard intake system. The lower lap time is achieved by widening the range of engine RPM which produces torque higher than 90% of the maximum value and lowering the engine RPM corresponding to the maximum torque. An intake system with ‘variable runner length’ is introduced to the 2015 racecar of KMUTT team. The values of intake lengths are determined from the wave equation with the goal of producing over 90% of the maximum torque of the baseline configuration over a range of engine RPM. Computer simulations are performed to determine the pressure at engine entry at various runner lengths. Finally, a prototype variable runner length intake system with linear motor actuators is constructed and installed on the racecar. Chassis dynamometer tests are performed to determine the engine torque for 3,000 – 10,500 RPM at all interested runner lengths.