HPI-55D1-18B Big Bore Throttle Body

Cable Driven™ Big Bore Throttle Body – 55mm CNC Ported Intake System (Black)

Maximize Airflow, Horsepower & Torque for Harley-Davidson Twin Cam Models

Engineered for precision performance, the Cable Driven™ Big Bore Throttle Body with CNC ported intake manifold is designed to unleash the full potential of your Harley-Davidson Twin Cam engine. Flow bench-tested and dyno-proven, this throttle body system delivers substantial gains in airflow, horsepower, and torque while maintaining OEM compatibility and reliability. Constructed from CNC-machined aluminum and featuring a brass throttle blade for long-lasting accuracy, this intake system sets the standard for precision and performance — Made in the USA for riders who demand the best.

Key Features

• Complete performance system — includes throttle body, CNC ported intake manifold, cable bracket, flanges, and seals

• Flow bench-tested and dyno-proven to deliver measurable horsepower and torque gains

• Brass throttle blade resists deflection for superior throttle position accuracy

• Sealed double roller bearing ensures smooth, reliable throttle operation

• Compatible with all OEM electronics and cruise control systems

• Fully CNC machined and internally ported for maximum flow and precision fitment

• Stock bolt pattern and air cleaner opening for easy installation

• Made in the USA with high-grade aluminum construction

• Emissions-related part – not legal for sale or use in California on pollution-controlled vehicles

Performance & Fitment

The Cable Driven™ 55mm Big Bore Throttle Body is designed for Harley-Davidson Twin Cam-equipped Touring, Softail, and Dyna models. Built for riders who demand dyno-proven results, this upgrade optimizes airflow for big-inch or high-compression engines, improving throttle response and mid-to-top-end power. Perfect for custom performance baggers and tuned street builds featuring Nowaskey Suspension, Hofmann Designs carbon fiber, or billet aluminum components, this throttle body is precision-built for smooth power delivery and uncompromising reliability.

Bore Size: 55.00 mm
Model: Cable Driven™
Color/Finish: Black
Material: CNC Machined Aluminum
Features: Intake Runner 1.80″, Sealed Double Roller Bearing
Units: Each
Weight: 2.65 lbs
Dimensions (L x W x H): 9.42″ x 6.54″ x 6.37″
Country of Origin: Made in the USA

Not legal for sale or use in California on pollution-controlled vehicles