aFe Silver Bullet Throttle Body Spacer 10-18 Toyota FJ Cruiser V6 4.0LaFe Silver Bullet Throttle Body Spacer 10 18 Toyota FJ Cruiser V6 4. 0L Silver Bullet throttle body spacers create turbulence in the air flow at the point just prior entry into the engine increasing horsepower, torque and improving throttle response and fuel efficiency. Silver Bullet throttle body spacers are constructed out of durable T 6061 billet aluminum and using a unique serrated helix entry to create turbulence at the manifold while eliminating