Air Filter Wraps & Pre-Filters

Is your open air filter mounted low in the engine bay, where water spray, road dust and gravel hit it? A pre-filter or filter wrap pulls over the outside of the filter and catches the coarsest dirt before it reaches the filter element itself. It is for you if you run an open filter on the street, on gravel roads or at track days.

What a pre-filter does

A pre-filter is an extra layer on the outside of an open air filter. It stops water spray, dust and coarse particles before the air reaches the filter element. It can extend the time between cleanings and protect the filter when the intake is exposed. The wrap does not replace the filter itself, but complements, for example, a conical filter from our universal air filters. You will find more related parts under air filter elements and wraps.

How to choose a pre-filter

The fit depends on the filter's dimensions, not on the car:

• Filter number: Many pre-filters are made for specific filters, e.g. Volant pre-filters for filter no. 5126 or Airaid pre-filters for filter 700-450/455/493. If you have bought one of our replacement filters, check the exact filter number.
• Dimensions: Universal wraps are typically specified by base and top diameter plus height, e.g. AEM wraps with a 6-inch base, 5 1/4-inch top and 5-inch height. Measure your filter before you choose.
• Driving conditions: A dense wrap can shield better against water and dust, but can also add more airflow restriction. The right choice depends on where the filter sits and how the car is used.

In this category you will find, for example, aFe with pre-filters in the Takeda and MagnumSHIELD series, as well as brands such as K&N Engineering, Uni Filter, Injen and BMC.

Installation and maintenance

The wrap is pulled down over the filter and must seal tightly at the base so that air does not bypass it. Clean it according to the manufacturer's instructions and let it dry completely before fitting. A clogged wrap can restrict airflow to the engine, so check it regularly, especially after driving in rain or on gravel.

Frequently asked questions

Can a pre-filter replace the air filter itself?

No. The pre-filter only catches the coarsest dirt and water spray. Fine filtration still takes place in the air filter element, so the wrap must always sit on the outside of an intact filter.

How do I find a pre-filter that fits my filter?

Look for the filter's number, or measure the base and top diameter as well as the height. Many pre-filters are specified for particular filter numbers, while universal wraps are chosen based on dimensions.

Does a pre-filter affect airflow to the engine?

It can, depending on material and density. A clean wrap typically adds limited extra restriction, while a clogged wrap can noticeably reduce airflow. So clean it regularly.