According to FSAE 2017-18 Rule Book, ARTICLE 3, IC3.2 and IC3.3 state that the maximum sound level should not exceed 110 dBC at 7500 RPM and 103 dBC at Idle (for the KTM 390 engine, which has 60 mm stroke length). Being a race car the space and weight constrains are there for the muffler and but the major concern is to reduce the backpressure of the muffler, so that maximum torque can be achieved from the engine. So the active muffler which works as a normal reflective muffler till the 7500 RPM range, after which an electronic controlled throttle mechanism is used to reduce the backpressure (since after 7500 RPM the noise level doesn't matter in FSAE) by using tach signal from the engine to control the throttle. The electronic throttle will be controlled using an ardino board to change the throttle opening angle and control the backpressure, with respect to the Engine RPM. This ensures that Noise level rules are met without compromising on the performance.