What is a VGT?
A Variable Geometry Turbocharger (VGT) is a turbocharger that is designed to allow the optimum air flow to be varied based on engine conditions. The optimum air flow or A/R (aspect ratio) varies depending on the engine speed (RPM) and engine load conditions. The A/R(aspect ratio) at low speeds is very different from the A/R(aspect ratio) at high speeds. Most variable geometry turbochargers (VGTs) are equipped with electronic actuator that use signals from the ECM to move the vanes or sliding sleeves in the VGT to increase or decrease the amount of exhaust gas to drive the turbine wheel, thereby increasing or decreasing the air intake flow to the turbocharger.