Silver Bullet Throttle Body Spacer by aFe. Billet Aluminum, Serrated/Helix Combination. What is inexpensive, takes only a few minutes to install, and results in more power and improved throttle response? The aFe Silver Bullet! The Silver Bullet Throttle Body Spacer installs between your throttle body and intake manifold. It creates turbulence and improves volumetric efficiency for more complete combustion.