The aFe Silver Bullet throttle body spacer (MPN 46-31007) mounts at the throttle body on the N55 3.0-liter turbocharged inline-six. It is CNC-machined from 6061-T6 billet aluminum and lengthens the intake path so air enters the engine with more velocity. The manufacturer lists dyno gains of up to +6 HP and +13 lb-ft of torque, along with sharper throttle response, which is the main reason to pay more than a stock throttle body setup costs.
Many helix-only spacers whistle under load. This one pairs a serrated entry with the helix, which the manufacturer says reduces that intake whistle while still building turbulence at the manifold. Custom screws are included, so you do not need to source hardware separately. For F30 335i and F32 435i owners searching for a billet throttle spacer, N55 intake whistle fix, or 46-31007 horsepower gain, this is the specific part to look for.
The manufacturer lists the N55 3.0L engine across the 135i, M235i, 335i, 435i, and X1 xDrive35i. Model-year coverage differs between the manufacturer's page and other listings, so enter your exact year and body code in the manufacturer's vehicle selector before ordering.
The manufacturer says the serrated/helix entry is designed to reduce the intake whistle common to helix-only spacers.
