Wastegate

Turbocharger Actuator acts as a pressure relief valve that controls the boost output of your turbo, diverting excess exhaust gases away from the turbine wheel. This controls the speed of the turbine, preventing it from over-speeding, and regulating the speed of the compressor.

Ultimately, this helps to protect the turbocharger from unnecessary wear and tear, by capping the maximum boost pressure of the turbo at a safe level.