aFe 21-24 Lexus IS350 3.5L V6 Silver Bullet Throttle Body SpaceraFe 21 24 Lexus IS350 3. 5L V6 Silver Bullet Throttle Body Spacer 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. All Silver Bullet Throttle Body Spacers are