What is it?
It refers to the direct expulsion of engine exhaust gases into the atmosphere without passing through a catalytic converter or muffler, or with a reduced number of mufflers, via the exhaust manifold and exhaust pipes.
Function
Since there are no catalytic converters or mufflers in the exhaust system, the exhaust flow is extremely smooth, but it also leads to increased noise. In high-speed regions, the smooth exhaust flow improves exhaust efficiency, thereby enhancing the engine's performance during high RPM. However, in low-speed regions, the excessively smooth exhaust flow results in low back pressure, causing a loss of low-end torque and a decrease in engine performance.
