Horsepower Inc. Max Flow™ 58 mm Throttle Body – Black – For Harley-Davidson Twin Cam Engines (1.76" Intake Runner)

Experience uncompromising performance with the Horsepower Inc. (HPI) Max Flow™ 58 mm Throttle Body, precision-engineered for Harley-Davidson® Twin Cam engines. Designed for riders demanding maximum airflow and horsepower, this CNC-machined billet aluminum throttle body delivers unmatched performance for big-inch and high-output builds.

With a 1.76" intake runner and a fully ported, internally polished design, the Max Flow™ 58 mm optimizes volumetric efficiency and throttle response. The sealed double roller bearing ensures smooth, consistent throttle operation, while the large plenum design increases mid- and top-end power.

Built to integrate seamlessly with OEM components, this throttle body is the go-to upgrade for serious Twin Cam performance builds. Proudly Made in the USA for riders who expect precision and results.

Key Features

• Performance-Oriented Design: Ideal for large cubic-inch Twin Cam engines demanding higher airflow.

• CNC-Machined Aluminum Construction: Precision-cut billet aluminum ensures durability and exact tolerances.

• Fully Ported for Flow Efficiency: Internal porting enhances throttle response and overall engine breathing.

• Smooth Operation: Equipped with sealed double roller bearings for precise and reliable throttle movement.

• Large Plenum Volume: Maximizes mid- and high-RPM performance without sacrificing low-end drivability.

• OEM-Compatible: Direct replacement for the stock throttle body and manifold — plug-and-play fitment.

• Made in the USA: Engineered, machined, and assembled by HPI’s performance specialists in Indianapolis.

Fitment – Harley-Davidson Twin Cam Models

Fits the following Harley-Davidson® Twin Cam models (2001–2005):

Touring Models:

• FLTRI Road Glide (2002–2005)

• FLHRI Road King (2002–2005)

• FLHRCI Road King Classic (2002–2005)

• FLHTI Electra Glide Standard (2003–2005)

• FLHTCI Electra Glide Classic (2002–2005)

• FLHTCUI Electra Glide Ultra Classic (2002–2005)

Softail Models:

• FLSTFI Fat Boy (2002–2005)

• FLSTNI Softail Deluxe (2005)

• FLSTCI Heritage Softail Classic (2001–2005)

• FXSTI Softail Standard (2001–2005)

• FXSTDI Softail Deuce (2001–2005)

• FXSTBI Night Train (2001–2005)

• FXSTSI Springer Softail (2001–2005)

• FLSTSI Heritage Springer (2001–2003)

Dyna Models:

• FXDI Dyna Super Glide (2004–2005)

• FXDLI Dyna Low Rider (2004–2005)

• FXDXI Dyna Super Glide Sport (2004–2005)

• FXDWGI Dyna Wide Glide (2004–2005)

• FXDCI Super Glide Custom (2005)

Fitment based on stock configuration. 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: 1.76"

• Material: CNC-Machined Billet Aluminum

• Finish: Black Anodized

• Compatibility: Twin Cam Engines (2001–2005)

• Units: Each

• Riding Style: Street / Performance / Touring

• Country of Origin: USA