K&N - RK-3909-1
Intake System-Harley Davidson
The latest addition to K&N's RK Series was developed to get more horsepower from your Twin Cam Harley-Davidson engine. Provides a significant airflow increase to the engine without sacrificing filtration.
K&N's RK Series was developed to get more horsepower from your Twin Cam Harley-Davidson engine. Built around the legendary K&N High-Flow Air Filter, the this RK Series assembly includes an innovative powder coated billet aluminum back plate that eliminates external breathers and features a built-in, dyno-tuned velocity stack. The result is a significant airflow increase to the engine without sacrificing filtration. This RK Series assembly retains a factory appearance by utilizing the stock air cleaner cover. The RK-3910-1 comes with a larger air filter and longer spacers than the RK-3909-1.
Air Box Included: No
Air Filter Color: Red
Air Filter Height: 1.625 in (41 mm)
Air Filter Inside Diameter: 6.188 in (157 mm)
Air Filter Material: Cotton Gauze
Air Filter Outlet Shape: Not Flanged
Air Filter Shape: Round
Air Filter Washable: Yes
CARB EO Number: D-269-35/55
Clamp Color/Finish: Not Applicable
Clamp Material: No Clamps Required
Clamp Style: No Clamps Required
Clamps Included: No Clamps Included
Color / Finish: Red Filter, Metal Top
Couplers Included: None
Estimated Horsepower Gain: 6.05 HP @ 5206 RPM
Inlet Diameter: 2.25 in (57 mm)
Mass Air Flow Sensor Adapter Included: No
Mounting Hardware Included: Yes
Neck Flange: 2.25 in (57 mm)
Oil Included: Yes
Overall Height: 1.688 in (43 mm)
Package Material: Paperboard
Package Type: Box
Product Style: Motorcycle Intake System
Replacement Filter: E-3972
Size: 7 Inch
Street Legal In All US States: See Vehicle Applications
Style: Oval
Top Material: Black Powder Coated
Top Style: Metal
TUV Approved (Europe): No
Warranty: No-Hassle Lifetime Limited
Weight: 3.3 lb (1.5 kg)
