By Vehicle
*
By Vin
Photo uploaded
By Dimension

More Power for the Open Road for H-D Motorcycles with K&N Intakes

Aircharger® intake systems provide a guaranteed increase in horsepower

It all began with motorcycles back in 1969, when Ken Johnson and Norm McDonald created the original oiled High-Flow Air Filter™ for their off-road bikes. Since that time, K&N® has continued to develop cutting-edge performance products for motorcycles, and offers intake systems for dozens of Harley-Davidson motorcycle models and years including newer Fat Boy, Softail, Road Glide, Street Glide, Road King, and Electra Glide models.

 

For Harley-Davidson owners interested in a guaranteed increase in horsepower and torque, K&N® offers performance-enhancing air intake systems available in multiple styles and finishes—engineered to protect your engine from most harmful dust, dirt, and contaminants, and designed to provide benefits including a guaranteed increase in horsepower and torque, top-quality engine protection, and robust engine sounds. For many models and years, these new intakes are 50-state legal* (please view the individual product pages for details on CARB status for your vehicle model/year).

Man riding Harley Davidson motorcycle on the highway

ABOUT AIRCHARGER® INTAKE SYSTEMS

AIRCHARGER® intake systems provide an aggressive appearance and increase in horsepower that you can feel. Featuring either a mandrel-bent aluminum or cast aluminum intake tube and a High-Flow Air Filter™, each system is designed to improve airflow to your engine while helping to defend against harmful contaminants. The kit includes all of the necessary mounting hardware for easy installation. Click on the individual product numbers below to view the individual product pages, and view full dynamometer testing sheets for most part numbers.


- Guaranteed to increase horsepower

- Custom throttle-body mounting plate

- Includes complete breather assembly and mounting hardware

- Available in bright mirror, textured silver, or textured black finish (where applicable)

- High-Flow Air Filter™ provides outstanding performance and protection

- 10-Year/Million Mile Limited Warranty


 

H-D Dyna with a K&N intake system

SEE WHAT HARLEY-DAVIDSON RIDERS ARE SAYING:

“It’s a no brainer to change out the original air intake for a K&N air intake system.” – Allan from Virginia [Part #RK-3926]
“I LOVE my K&N Cold Air intakes on my 2008 Harley Street Bob, and in my 2015 Chrysler 300C. SIGNIFICANT boost in performance and sound. K&N is the ONLY way to go.” – William from Florida [Part #57-1564]
“Absolutely love this setup. 2007 Harley Street Bob. Substantial differences noticed. Acceleration, performance, engine sound. Would definitely recommend.” – Robert from New York [Part #63-1125]
“This high flow intake system was very easy to install and has made a marked improvement in my bike's performance.” – Brian from Canada [Part #RK-3910-1]
“If you are thinking about getting one, do it. Has completely awakened my now 2 year old bike.” – Mike from California [Part #RK-3931]

THE 57-1134 & 57-1134S AIRCHARGER® INTAKE SYSTEMS

ESTIMATED GAIN: +6.11 HP**

The 57-1134 intake after installation on a Harley Davidson

THE 57-1139 & 57-1139S AIRCHARGER® INTAKE SYSTEMS

ESTIMATED GAIN: +3.44 HP**

The 57-1139S intake after installation on a Harley Davidson

THE 57-1137 & 57-1137S AIRCHARGER® INTAKE SYSTEMS

ESTIMATED GAIN: +5.35 HP**

Other series are also available for many H-D motorcycle models and years:

RK SERIES INTAKE SYSTEMS

RK Series Intake Systems feature an oversized K&N® High-Flow™ Air Filter, dyno-tuned velocity stack, and integrated breather system—helping to provide a significant increase in airflow and engine performance. RK intake systems fit neatly behind the factory air cleaner cover to maintain a stock appearance, and come in either a standard capacity or large capacity style depending on your performance needs.


- Guaranteed to increase horsepower

- Custom aluminum backing plate provides solid mounting surface

- Built-in breathers replace external OE breathers

- Oversized K&N High-Flow™ Air Filter for excellent filtration and contaminant protection

- Available in standard or large capacity

- Built-in dyno-tuned velocity-stack to direct airflow to the throttle body

- 10-Year/Million Mile Limited Warranty


 

RK Intake for Softail Slim, Fat Boy, Heritage Classic, and More

ESTIMATED GAIN: +3.33 HP**

K&N cold air intake for Heritage Classic and Fat Boy

STREET METAL™ INTAKE SYSTEMS

A high-quality aluminum cover and oversized K&N High-Flow™ Air Filter provide the Street Metal™ intake systems with a sleek appearance, while offering enhanced performance through an increase in airflow and excellent engine protection. The original Street Metal™ line comes in various shapes and sizes, offering increased capacity options for performance-minded H-D riders. In addition, two new Street Metal intake system lines are now available—the Shaker and the Sidedraft. Both feature classic good looks, built-in breathers to replace factory breathers, and a built-in dyno-tuned velocity stack—while also providing exceptional contaminant protection and outstanding performance.


- Guaranteed to increase horsepower

- Built-in breathers replace external OE breathers

- Custom backing plate with integrated velocity stack provides solid mounting surface

- High-quality aluminum cover

- Oversized K&N High-Flow Air Filter™ for excellent filtration and long service intervals

- Built-in dyno-tuned velocity-stack directs airflow to the throttle body

- 10-Year/Million Mile Limited Warranty


 

The K&N RK-3948

*Some intake systems are not legal for sale or use on any pollution controlled motor vehicle in California. View individual product pages for CARB status on each part number for a specific vehicle make, model, and year.

**Horsepower gains vary among products and applications, but each K&N performance air intake system is designed to increase airflow efficiency for specific vehicles and their engines. Each kit undergoes significant testing to help ensure that the filter and intake tube are engineered to deliver large increases in airflow and horsepower. Please visit individual product pages to view horsepower estimates for your specific vehicle.

Harley-Davidson® is a registered trademark of H-D Michigan, Inc.

Warning!

We have detected that you are using an outdated browser that will not allow you to access certain features of our website. We strongly recommend installing an updated browser, such as Google Chrome, for an improved browsing experience.