A mechanical wastegate is a device used in turbocharged engines to control the amount of exhaust gas that flows to the turbine. It helps regulate boost pressure by opening and closing based on the engine's performance needs. When the desired boost level is reached, the wastegate opens to divert some exhaust gases away from the turbine, preventing over-boosting and potential engine damage. Typically, mechanical wastegates are spring-actuated, meaning they rely on a spring to determine when to open. The spring's tension is calibrated to a specific boost pressure, ensuring that the engine operates efficiently. This system is crucial for maintaining optimal performance in vehicles equipped with a turbocharger.