HPi 62mm Throttle Body for Harley Milwaukee-Eight (2017-2023) | Horsepower Inc.

$120.00

Frequently Asked Questions
1. Will this 62mm throttle body fit my stock Harley M8?
While the HPi 62mm unit is a direct bolt-on for 2017-2023 Milwaukee-Eight engines, it is specifically designed for performance-modified bikes. It is highly recommended for engines with upgraded cams, high-flow injectors, or big-bore kits (117ci to 131ci). For a completely stock 107ci engine, the gains may be minimal without other supporting mods.
2. Do I need a special air cleaner for the 62mm HPi unit?
Yes. Because the intake diameter is larger than the factory 55mm unit, you will need a high-flow air cleaner with a matching backing plate. Many performance air cleaners (like those from S&S, Arlen Ness, or HPi’s own line) offer specific fitments for 62mm throttle bodies.
3. Is a dyno tune required after installation?
Absolutely. Installing a 62mm throttle body significantly changes the air-to-fuel ratio of your engine. Running the bike without a proper recalibration via a flash tuner (like the Dynojet Power Vision) can lead to lean conditions, overheating, and potential engine damage.
4. What are the benefits of billet aluminum over the stock plastic manifold?
The factory plastic (polymer) manifolds are known to “heat soak” and, in high-performance or high-heat scenarios, can actually warp or develop intake leaks. The HPi CNC-machined billet aluminum construction provides a more stable seal, handles higher heat cycles, and eliminates the risk of warping under pressure.
5. Does this unit include the electronics and fuel injectors?
Typically, the HPi throttle body is designed to reuse your factory electronics (TPS and IAC) to keep costs down and ensure compatibility. Fuel injectors are usually sold separately, though we recommend upgrading to high-flow injectors if you are building a high-horsepower M8.
6. Can I install this on a 2024 or newer model?
This specific unit is designed for the 2017-2023 cable or early throttle-by-wire M8 configurations. If you have a 2024+ Touring model (like the new CVO or redesigned Road Glide/Street Glide), please contact us to verify fitment, as some electronics and intake geometries have changed.

HPi 62mm High-Flow Throttle Body for Harley-Davidson M8 (2017-2023)
Unlock the full potential of your Milwaukee-Eight engine with the HPi 62mm Throttle Body. Specifically engineered for 2017-2023 Harley-Davidson Touring and Softail models, this intake upgrade is the industry standard for riders chasing maximum horsepower and torque. Whether you are running a Stage IV kit or a 131ci big-bore monster, the stock 55mm plastic unit is a bottleneck—this Horsepower Inc. (HPi) masterpiece is the solution.
Precision Engineering for Maximum Airflow
The HPi-62mm-M8 features a fully CNC-machined billet aluminum construction, replacing the failure-prone factory plastic components. By increasing the bore size to 62mm, you allow for a massive increase in air volume, resulting in a crisper throttle response and a relentless pull across the entire RPM range. This isn’t just a part; it’s a performance necessity for builds exceeding 120HP.
Key Features & Benefits:
• Massive 62mm Bore: Provides significantly higher CFM (Cubic Feet per Minute) over the stock Harley M8 throttle body.
• Billet Aluminum Construction: Eliminates the warping and heat-soak issues common with factory plastic intake manifolds.
• Improved Throttle Response: Precision-machined butterfly valves ensure smooth, linear power delivery without sticking.
• Direct Bolt-On Fitment: Designed to fit 2017-2023 Milwaukee-Eight engines (Road Glide, Street Glide, Low Rider ST, etc.).
• Made in the USA: Manufactured by Horsepower Inc., the most trusted name in V-Twin induction performance.
Why Upgrade Your M8 Intake?
The Milwaukee-Eight engine thrives on air. Stock induction systems are designed for emissions and fuel economy, not raw power. If you’ve upgraded your cams, injectors, or displacement, your engine is starving for oxygen. The HPi 62mm High-Flow Intake provides the “lungs” your bike needs to breathe, making it the perfect match for high-lift cams and ported heads.
Fitment & Compatibility:
• Harley-Davidson Touring: 2017–2023 Road Glide (FLTR), Street Glide (FLHX), Road King (FLHR), and Electra Glide (FLHT).
• Harley-Davidson Softail: 2018–2023 Low Rider S/ST (FXLRS/ST), Fat Boy (FLFB), Fat Bob (FXFB), and Heritage Classic (FLHC).
• Engine Types: 107ci, 114ci, 117ci, 124ci, 128ci, and 131ci Milwaukee-Eight.
Technical Note:
Due to the significant increase in airflow, professional dyno tuning (using a Screamin’ Eagle Pro Street Tuner, Dynojet Power Vision, or Vance & Hines FP4) is required to ensure your air-fuel ratios remain optimized and safe.