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Spun Round Housing Top & Bottom with 2-Stage Foam Element

The UNI Automotive 2-Stage foam filter outperforms the competition providing greater air flow and superior protection.

The principle of how foam air filters work is simple: "Open Cell" Polyurethane Foam is wetted with specially developed filter oil. The "sticky" filter oil is suspended in the path of the dirty air on the strands of the web-like cell structure of the foam. This makes it impossible for dirt to pass through the depth of the filter without sticking to the strands. As the outer strands become loaded with dirt particles, the wetted strands down stream start trapping dirt, allowing the entire thickness to be utilized. This prevents surface loading or air restriction for 80% of the service life of the air filter element. When the filter is sufficiently dirty, it can be easily washed, re-oiled, and re-used.

With Uni's dual stage element the need for outerwear's prefilters and such are not required. You will find the UNI filters much easier to clean and maintain than K&N or other popular brands.

If you would like more information on foam air filters, please download Filter Information PDF file.

Be sure to download and print the oiling instructions for the foam air filters.

Your typical dirt late model race car will use a 14" x 5" or a 14" x 4" filter. Open Wheeled Modifieds and Pro-Stocks tend to use the 14" x 4". 

(outerwears is registered trademark of the outerwears company inc., K&N is a registered trademark of K&N Engineering)

HDM also offers foam UNI Pre-Wraps to fit your existing filter, please email your filter diameter and Height for pricing.

Uni offers cone filters for 3" Air In-takes on high performance street cars. This filter measures 3" ID x 6 1/2 Base OD x 5 1/4 Top OD x 8" length.   


This filter also works well on Jeeps and other off road vehicles. Be sure to check your hood clearance if applicable. This filter is also available in an 11" length version.

5.5oz Filter Oil Aerosol...  $5.50ea (no air shipments for any reason)




HDM nor UNI will be held responsible for any engine failure due to improper or unapproved use of a UNI filter.



Spy Optics available online.

Thor Oil and Tire Prep now available.

Hyper Coil brand coil over springs are now available

Digatron Gauges and Instruments online ordering.

Rivets and Sheet Metal now available.



 Latest Updates...

HDM has added the following to our product line.

Karting Jackets

FSR Radiators

Racing gloves

Braces & Supports

Racing  Wheels




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