Horsepower Inc. Max Flow™ 58 mm Throttle Body – Black – For Harley-Davidson Twin Cam (2006–2017)

The Horsepower Inc. (HPI) Max Flow™ 58 mm Throttle Body is built to deliver exceptional airflow and throttle response for Harley-Davidson® Twin Cam engines. Designed and manufactured in the USA, this high-performance throttle body offers precise fitment, durable construction, and dyno-proven results.

Machined from billet aluminum and internally ported for maximum flow, the Max Flow™ is ideal for big-bore Twin Cam builds and high-output applications. Its 1.80" intake runner and large plenum design optimize volumetric efficiency, improving horsepower and torque across the RPM range.

With a sealed double roller bearing for smooth throttle actuation and direct OEM compatibility, this throttle body combines race-level performance with factory-level reliability — all backed by American craftsmanship.

Key Features

• Direct OEM Replacement: Fully replaces stock throttle body and manifold; compatible with factory components and sensors.

• Precision-Machined Construction: CNC-cut from billet aluminum for strength and accuracy.

• High-Flow Engineering: 58 mm bore with internal porting and a large plenum for maximum mid- and top-end power.

• Smooth Throttle Operation: Sealed double roller bearings provide precise, consistent throttle feel.

• Built for Big-Inch Engines: Designed to support large displacement and high-performance Twin Cam builds.

• Made in the USA: Built to aerospace-level standards by HPI’s performance engineering team.

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)

• FLSTSCI Softail Springer Classic (2006)

• FXST Softail Standard (2006–2007)

• FXSTC Softail Custom (2007–2010)

• FXSTB Night Train (2006–2009)

• FXSTS Springer Softail (2006–2007)

• FXSTD Softail Deuce (2006–2007)

• FXSB Breakout (2013–2015)

• FXS Blackline (2011–2013)

Dyna Models:

• FXDB Street Bob (2006–2017)

• FXDC Super Glide Custom (2007–2014)

• FXDI Dyna Super Glide (2006–2010)

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

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

• FXDF Fat Bob (2008–2017)

• FLD Switchback (2012–2016)

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

Technical Specifications

• Product Name: Throttle Body

• Model: Max Flow™

• Type: Single Bore

• Bore Size: 58 mm

• Intake Runner: 1.80"

• Material: CNC-Machined Billet Aluminum

• Finish: Black Anodized

• Compatibility: Harley-Davidson Twin Cam (2006–2017)

• Units: Each

• Riding Style: Street / Performance / Touring

• Country of Origin: USA