Performance filters.. Foam is best

One of the simplest, cheapest, and easiest performance improvements you can make to your car is the engine air-filter, yet it is one that is commonly overlooked. It is a very simple upgrade from the OEM paper filter to a foam filter and can be home installed on your driveway without the need for any special tools in a few minutes.

The primary role of the engine air-filter is to prevent your engine from being damaged with dirt, dust, sand, and other contaminants that might get drawn into the engine intake. Most OEM air-filters are constructed from pleated paper, manufacturers use them as pleating increases the surface area and it is, a slightly cheaper option than the alternatives. Paper filters are disposal and are normally replaced when your car is serviced, as they tend to clog up between services.

The problem with paper as an air-filter material is, that it does a great job of blocking larger contaminants from getting into the engine, but it can also be restricting especially as the filter gradually clogs up. This has a negative effect on performance. In the simplest terms, more air, more fuel, equals a bigger bang and more performance. 

The pleating on paper air-filters as I said, is designed to increase surface area which is desirable as this reduces pressure drop and allows a freer airflow.  As particles begin to build up between the pleat pack recesses however, it blocks up the potential flow areas reducing performance. Pleated filters are good at arresting large particles and can initially be more free flowing, but they can allow smaller particles through which could cause increased engine wear. An alternative to the OEM paper filter is a foam filter.

Several years ago, we partnered with well-known air-filter manufacturer Pipercross to create the Swallows Racing range of performance panel filters for the modern Jaguar range. They are a great first step in improving performance and making the engine breath more easily. The foam is layered in a format that catches different size particles at different levels. This layering, and the thickness of the foam, is what allows our SR filters to catch dirt, but not get blocked up in the same way an OEM paper or even cotton gauze filters can. The oil that is impregnated within the foam further assists in catching and spreading the dirt throughout, stopping build up in one area. This means that from service to service, the filter retains full breathing potential and isn’t slowed down by a build-up of dirt which paper filters commonly suffer from. (see diagrams below)

Paper Filter