HPI HPI-55MF6-76 Maxflow Throttle Body Cam Bagger 55/58MM

( Brand: Hpi ), ( Manufacturer Part Number: HPI-55MF6-76 ), ( Part Type: Throttle Cam ), ( Material: Aluminum ), ( Vintage Part: No )

Review HPI 55/58mm Maxflow Throttle Body Harley Davidson Cam Bagger fits TWIN DYNA 2006–2017

The **HPI HPI-55MF6-76 55/58mm MaxFlow Throttle Body** is a meticulously engineered performance upgrade designed specifically for Harley-Davidson s **2006 2017 Twin Cam Dyna and Bagger models**, including the Sportster 1200, Softail, and Dyna Low Rider series. This high-performance throttle body is crafted to enhance throttle response, airflow efficiency, and overall engine breathing, making it an ideal choice for riders seeking a noticeable boost in power and smoothness without the need for extensive modifications. The **55/58mm MaxFlow design** strikes an optimal balance between stock compatibility and aggressive performance, allowing for a seamless integration with the stock fuel injection system while delivering a measurable increase in torque and acceleration. Constructed from high-grade materials, including a durable aluminum housing and precision-machined internals, this throttle body is built to withstand the demands of high-performance riding while maintaining reliability. The **MaxFlow technology** ensures minimal restriction at all throttle positions, reducing vacuum loss and improving engine efficiency, particularly noticeable during mid-range power delivery and under heavy load. Whether you're cruising on the highway, tackling spirited acceleration from a stop, or pushing the limits in a track day setting, this throttle body delivers a refined yet aggressive driving experience. Its **direct bolt-on installation** requires minimal modification, making it a straightforward yet impactful upgrade for both street and light track applications. For riders who demand more from their Twin Cam engines without compromising on drivability or reliability, the HPI HPI-55MF6-76 is a precision-crafted solution that elevates performance with confidence.

The **HPI HPI-55MF6-76 (55/58mm MaxFlow Throttle Body)** is a popular aftermarket throttle body designed for Harley-Davidson Twin Cam (2006 2017) Dyna and Street Glide models. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros**

1. **Improved Throttle Response**

The MaxFlow throttle body features a larger bore (55/58mm) compared to the stock unit, allowing for better airflow and quicker throttle response. This can make the engine feel more responsive, especially in low-RPM situations where stock throttle bodies may feel sluggish.

2. **Better Fuel Economy (Under Certain Conditions)**

Some riders report improved fuel efficiency at highway speeds due to the throttle body s ability to maintain a more stable idle and reduce hesitation. However, this is situational and depends on tuning and engine condition.

3. **Smoother Power Delivery**

The larger bore helps reduce "throttle lag" and provides a more linear power curve, which can make the bike feel more refined, especially in stop-and-go traffic or when cruising.

4. **Compatibility with Performance Mods**

If you plan to add other performance parts (such as a high-flow air intake, exhaust, or ECU tune), this throttle body can help ensure that the engine isn t limited by airflow restrictions.

5. **Easy Installation**

The MaxFlow throttle body is a direct drop-in replacement for the stock unit, requiring minimal modifications. It includes all necessary gaskets and mounting hardware, making installation straightforward for most riders.

6. **Positive Community Feedback**

Many Harley-Davidson forums and reviews highlight that this throttle body is a reliable choice for those looking to enhance throttle response without major engine modifications.

7. **Durability**

HPI is a well-known brand in the aftermarket performance community, and this throttle body is built to withstand the demands of daily riding, though it is not designed for extreme high-performance applications.

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### **Cons**

1. **Not a Power-Increasing Modification**

While the throttle body improves airflow, it does not significantly increase horsepower or torque on its own. For meaningful power gains, it must be paired with an ECU tune (such as from HPI, Power Vision, or a custom tuner).

2. **Requires a Tune for Optimal Performance**

Without a tune, the throttle body may cause rough idling, stalling, or even damage to the engine over time. The stock ECU may not properly compensate for the increased airflow, leading to lean conditions at idle or low RPMs.

3. **Potential for Rough Idling (Without a Tune)**

Some riders report that the throttle body can make the engine idle roughly if not paired with a tune. This is because the stock ECU may not adjust fuel delivery correctly for the larger bore.

4. **Limited to Twin Cam Engines (2006 2017)**

This throttle body is specific to the Twin Cam platform and will not fit other Harley models, such as Evolution or newer Evolution engines.

5. **Cost Relative to Benefits**

For riders who are not tuning their bike or adding other performance parts, the cost of the throttle body may not justify the perceived benefits. The improvement in throttle response may be subtle unless paired with other mods.

6. **Potential for Increased Exhaust Backpressure (If Not Tuned)**

If the exhaust system is not optimized for the increased airflow, the throttle body could contribute to backpressure, reducing overall performance. This is why a tune is essential.

7. **Not a "Set and Forget" Mod**

Unlike some aftermarket parts, this throttle body requires attention to ensure the engine remains balanced. Ignoring it can lead to drivability issues or engine stress.

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### **Conclusion**

The **HPI HPI-55MF6-76 throttle body** is a solid choice for Harley-Davidson Twin Cam (2006 2017) Dyna and Street Glide owners who want to enhance throttle response and prepare their bike for future performance modifications. It is particularly beneficial if you plan to add other parts like an air intake, exhaust, or ECU tune. However, it is not a standalone power-increasing mod and must be paired with a tune to avoid drivability issues.

For riders who are content with their stock setup and do not plan to tune or modify further, the benefits may not be worth the cost. On the other hand, if you are investing in a performance build or simply want a more refined throttle feel, this throttle body is a worthwhile addition.

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### **Recommendation**

- You are planning to add other performance parts (intake, exhaust, tune).

- You want smoother throttle response and better low-end feel.

- You are willing to invest in an ECU tune to maximize benefits.

- You ride in stop-and-go traffic or appreciate a more refined power delivery.

- You are not tuning your bike and want a "plug-and-play" improvement.

- You are on a tight budget and only want subtle, non-performance-related upgrades.

- You do not plan to modify your bike further in the near future.

If you decide to install this throttle body, pair it with a **proper ECU tune** (such as from HPI, Power Vision, or a custom tuner) to ensure optimal performance, smooth idling, and longevity. Additionally, consider upgrading your air intake and exhaust to complement the throttle body s improvements.

Details:

Pulled from a running bike. 5.3g HPI injectors. Everything works great. HPI 55/58mm throttle body for 06 17 Twin cam.

Includes everything shown for a complete ready to bolt on unit.

part #: hpi-55mf6-76 price

• $650.00

specifications intakefuelmotorcycle:

• for models: Twin, Dyna
• for makes: Harley, Davidson
• for years: 2006-2017
• brand: Hpi
• mpn: Hpi-55mf6-76
• part type: Throttle Cam
• material: Aluminum
• vintage part: No

offer intakefuelmotorcycle:

• quantity: 1
• options: Ship-to-home
• availability: In Stock
• best offers: True
• started: June 1, 2026
• sold: 0

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• other
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returns intakefuelmotorcycle:

• policy: No Returns

general intakefuelmotorcycle:

• Motorcycle Scooter Parts Accessories > Air Intake Fuel Delivery > Other Air Intake Fuel Delivery
• condition: Used

seller intakefuelmotorcycle:

• # reviews: 1770
• rating: 99.0%
• city: Portland, Oregon

shipping intakefuelmotorcycle:

• transit: 4-8 Days
• service: USPS Ground Advantage
• class: Standard
• carrier: USPS
• type: Calculated
• cost: $15.10

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