It allows you auto-fire by pressing the selected button (A, B,X,Y). Thus, you avoid repetitive pressure of the same key. To activate the Turbo mode: 1.Hold the [TURBO] button 2.Then press the selected button(A, B, X, Y) 3.The Turbo function is enabled To deactivate the Turbo mode: 1.Press and hold the button where the Turbo function is enabled. How to Use Turbo in GTA V When you fit the turbo to a car in GTA V, you'll see it give a boost to the acceleration stat of it. Then, when you're in a race and your car changes gear, you'll hear a.