Horsepower Inc. Max Flow™ 55 mm Throttle Body – Black – for Harley-Davidson Twin Cam (2006–2017)

Unlock hidden power and throttle precision with the Horsepower Inc. (HPI) Max Flow™ 55 mm Throttle Body.
Designed and built in the USA, this high-flow unit directly replaces your factory throttle body and manifold, delivering smoother throttle response and more efficient airflow—perfect for performance Twin Cam builds or upgraded touring applications.

Machined from billet aluminum and internally ported for maximum volumetric efficiency, the Max Flow™ Throttle Body uses a 1.80-inch intake runner to maintain strong low-end torque while dramatically improving mid- and high-RPM horsepower.
A sealed double-roller bearing guarantees crisp, reliable throttle movement for miles of trouble-free performance.

Key Features

• Direct OEM Replacement – Bolts on using stock hardware; fully compatible with OEM sensors and components.

• CNC Billet Aluminum Body – Lightweight, precision-cut construction for strength and long-term durability.

• High-Flow 55 mm Design – Increases air velocity and engine efficiency for noticeable performance gains.

• Internally Ported & Polished – Smooth, unrestricted air passage for consistent throttle response.

• Large Plenum Chamber – Enhances airflow balance across cylinders for improved power delivery.

• Smooth Operation – Sealed double roller bearing ensures stable, responsive throttle feel.

• Proudly Made in the USA – Built to exacting standards by HPI performance engineers.

Fitment – Harley-Davidson Twin Cam Models (2006 – 2017)

Touring Models:

• FLHR Road King (2007)

• FLHRS Road King Custom (2007)

• FLHX Street Glide (2006 – 2007)

• FLTR Road Glide (2006 – 2007)

• FLHT Electra Glide Standard (2006 – 2007)

• FLHTC Electra Glide Classic (2006 – 2007)

• FLHTCU Electra Glide Ultra Classic (2006 – 2007)

Softail Models:

• FLSTC Heritage Softail Classic (2006 – 2015)

• FLSTF Fat Boy (2006 – 2015)

• FLSTN Softail Deluxe (2006 – 2015)

• FLSTFB Fat Boy Lo (2010 – 2015)

• FLSTSB Cross Bones (2008 – 2011)

• FXSB Breakout (2013 – 2015)

• FXS Blackline (2011 – 2013)

• FLS Softail Slim (2012 – 2015)

• FLD Switchback (2012 – 2016)

• FXSTC Softail Custom (2007 – 2010)

• FXSTB Night Train (2006 – 2009)

• FXSTD Softail Deuce (2006 – 2007)

Dyna Models:

• FXDB Street Bob (2006 – 2017)

• FXDC Super Glide Custom (2007 – 2014)

• FXDI Dyna Super Glide (2006 – 2010)

• FXDL Dyna Low Rider (2007 – 2009, 2015 – 2017)

• FXDWG Dyna Wide Glide (2006 – 2008, 2010 – 2017)

• FXDF Fat Bob (2008 – 2017)

Fitment based on stock configurations. Not legal for sale or use in California on pollution-controlled vehicles.

Technical Specifications