Wehrli Custom Outerwears Air Filter Cover

We use and recommend these Outerwears Air Filter Covers for all WCFab air filters used in our turbo kits and intake kits. These Pre-filters are designed to deflect the damaging debris, which can prematurely clog air filters, compromising peak air-flow and horsepower. The Pre-filter also extends the time between servicing intervals for your primary air filter media reducing costs and increasing convenience. 

These Pre-filters contain uniform micron openings and are run dry meaning no additional oils or additives are required. Running a dry Pre-filter means there is no dirt sticking to the oil creating premature loss of airflow and horsepower. Only those particles of dirt smaller than .005" get into the actual air filter, the larger particles simply fall off the pre-filter. In addition, these filter covers are constructed with a woven mesh that is specially treated at the mill using a proprietary process to repel water. This hydrophobic water repellent process is not sprayed on; consequently, there is no airflow loss. Whether you use your vehicle for everyday driving or for hard core off-road racing, Pre-filters will work for you to protect and extend the life of your performance air filter and engine.

Water Resistant - The filter cover's Hydrophobic treatment helps repel moisture and protect against water entering into the engine due to puddle splash or heavy rainstorms. Although our Pre-Filters are proven to be extremely effective in repelling water, please keep in mind they are NOT WATER PROOF. If submerged, your intake can hold or pass water. This treatment will last for six months to one year, depending on use and conditions. As a general guideline we recommend replacing your Outerwears air filter cover with every other air filter service to help maintain its intended performance benefits. A quick test can help determine if it is time to change your Pre-Filter. Simply take an ordinary clean spray bottle filled with water and gently spray the Pre-Filter. If the water beads off the Pre-Filter, your water repellency is still working. If you see water enter through the Pre-Filter, it is time to purchase a new cover.

Maintenance & Cleaning - Depending on driving conditions, service intervals may vary. We recommend you make a visual inspection as often as you would normally service your vehicle. If your vehicle sees a lot of dirt track competition (pulling / dirt drags) or dirt road driving, we recommend viewing the Pre-Filter at least after every race or trip. If you can see a significant amount of dirt, you should clean the Pre-Filter. If the only driving you experience is the street, we recommend checking the Pre-Filter every 3,000-5,000 miles. Although your Pre-filter may not require a thorough cleaning, you may want to shake off any excess dirt to maintain your optimum horsepower and fuel efficiency and then simply reinstall. Caked debris can be loosened by soaking this filter cover, after being removed from your main filter and vehicle, in a mild soapy water solution and then rinsed clean and allowed to dry before re-installation. Do not scrub or use aggressive cleaning chemicals as the pre-filter and hydrophobic treatment can become damaged resulting in reduced efficiency and premature failure.