In fuel injected engines, the throttle body is the part of the air intake system that controls the amount of air flowing into the engine, in response to driver accelerator pedal input in the main. The throttle body is usually located between the air filter box and the intake manifold, and it is usually attached to, or near, the mass airflow sensor.

The largest piece inside the throttle body is the throttle plate, which is a butterfly valve that regulates the airflow. Have a larger diameter throttle body produces more air flow with equals more power. The upgrades should be used in conjunction with the competition plenums.

This is a 82mm Thottle body.