High-Airflow Drag Racing Top Assembly for Large-Diameter Scoop-Mount Air Cleaners
The K&N KNN66-3330R is an X-Stream air flow top assembly designed for drag racing applications requiring maximum airflow volume through a large-diameter scoop-mount air cleaner. With a 9-inch outer diameter, 7.313-inch neck flange, and 3-inch overall height, this universal top assembly is engineered to sit atop K&N’s X-Stream base units to create a complete assembly that channels high-velocity air down into the carburetor or throttle body while protecting the engine from debris in the staging lanes and on the track.
Key Features
- 9-Inch Outer Diameter: Large outer diameter maximizes air flow surface area for carbureted or throttle body applications demanding high-volume induction
- X-Stream Design: Vented top directs air flow efficiently down through the base filter element while acting as a scoop mount to feed forced induction from a hood scoop
- 7.313-Inch Neck Flange: Large neck flange provides a stable mounting surface over the base filter assembly with positive retention
- 3-Inch Height: Low-profile 3-inch height keeps the overall assembly height manageable for hood scoop fitment and carb clearance
- Universal Drag Racing Fit: Not vehicle-specific; designed for any drag racing build using a compatible X-Stream base unit
- K&N Engineering Quality: Manufactured to the same dimensional and material standards as K&N’s full air filter product line
Specifications
| Detail | Value |
|---|---|
| Part Number | KNN66-3330R |
| Brand | K&N Engineering |
| Outer Diameter | 9 in |
| Neck Flange Diameter | 7.313 in |
| Height | 3 in |
| Style | X-Stream Top Assembly |
| Fit | Universal (drag racing) |
| UPC | N/A |
What’s Included
- 1x X-Stream top assembly
About K&N Engineering
K&N Engineering has been manufacturing performance air filters, intake systems, and air flow components since 1969. Based in Riverside, California, K&N products are used across motorsport disciplines from drag racing and circle track to off-road and road racing, as well as on millions of street-driven performance vehicles worldwide.
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Frequently Asked Questions
What is this top assembly?
This is a K&N KNN66-3330R X-Stream air flow top assembly with a 9-inch outer diameter, 7.313-inch neck flange, and 3-inch height, designed for drag racing air cleaner builds that use a hood scoop to force-feed air to the engine. It is a universal component for use with compatible X-Stream base filter units.
Is a base filter included?
No. This is the top assembly only. A compatible X-Stream base filter unit is required to complete the air cleaner assembly; the base unit and any carb hat or adapter plate are sold separately.
What vehicles does this fit?
This is a universal drag racing component not designed for any specific vehicle. It is intended for competition builds using a hood scoop-fed air cleaner setup. Confirm that your base unit dimensions match the 7.313-inch neck flange before ordering.
Can this be used on a street car?
This is primarily a competition-oriented component, but it can be used on any street vehicle with a compatible X-Stream base assembly and sufficient hood clearance. Street use without a scoop means the top primarily acts as a rain and debris deflector over the filter element.
What is the purpose of the X-Stream design?
The X-Stream design uses a vented top configuration that directs inbound scoop air efficiently down through the filter element to the carburetor or throttle body. It is engineered to maximize airflow volume in applications where a ram-air or hood scoop is feeding forced air into the air cleaner from above.
Does this fit a standard 14-inch air cleaner base?
No. This top assembly is designed for K&N’s X-Stream base units, not for standard round air cleaner bases. The 9-inch outer diameter and 7.313-inch neck flange are specific to the X-Stream product family. Verify base unit compatibility before ordering.
Is this component reusable?
Yes. The top assembly itself does not require replacement as part of routine maintenance. Maintenance intervals apply to the underlying filter element in the base unit, not the top cap.
What material is the top assembly made from?
This component is manufactured to the same dimensional and material standards as K&N’s air cleaner product line. Refer to K&N’s product documentation for the specific material call-out if material confirmation is needed for your application.
Installation Instructions
- Confirm the X-Stream base unit is properly installed and seated on the carburetor or throttle body adapter.
- Position the top assembly over the base filter element, aligning the neck flange concentrically with the base unit.
- Press the top assembly down onto the base unit until fully seated and the flange sits flush against the top of the filter element.
- Secure the top assembly to the base unit per the recommended retention method (wing nut or stud, depending on base unit configuration).
- Verify the assembly is centered over the carb or throttle body and does not contact the hood scoop opening or adjacent components.
- If using with a hood scoop, align the scoop opening directly over the top assembly before fastening the scoop in final position.
