aFe Silver Bullet Throttle Body Spacer 2010-2023 Toyota FJ Cruiser / 4Runner V6 4.0LSerrated Helix Design: The Serrated Helix combination design creates intake turbulence in the combustion chamber. This turbulence breaks up the fuel which creates a more complete combustion cycle increasing horsepower, torque and improving throttle response. The Serrated Helix combination design also reduces intake whistle that occurs with Helix only designs. 6061 T6 Billet Aluminum Construction: All Silver Bullet Throttle Body Spacers are constructed