aFe Nissan Frontier 20-22 V6-3.8L Silver Bullet Throttle Body SpacerThe 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 (US PAT 07055513). All Silver Bullet Throttle Body Spacers are constructed from 6061 T6 billet aluminum precision