What's inside a VGT? Gale Banks opens up the variable geometry turbo from a Duramax L5P to show the inner workings of this ingenious technology. VGTs use an electronic actuator connected to internal vanes in order to change the turbine shaft speed at the same turbine drive pressure. The result is that VGTs can act like a smaller turbo at low speeds to quickly spin up and minimize turbo lag, then open up the vanes to reduce back pressure and work more efficiently. #amsoil | Banks Power