Pod Air Filters

A pod air filter is a compact open filter that mounts on the end of an intake pipe in place of an airbox. The pods in this category combine the filter element with a velocity stack, a flared inlet that sits inside the element, in 3-inch and 3.5-inch sizes.

Air entering a plain pipe end must turn sharply around the lip. The flow separates from the wall and the effective opening shrinks, which adds restriction. A velocity stack’s rounded bell mouth lets the air speed up smoothly, so more of the bore carries flow. Inside a pod, the stack keeps that smooth entry while the element keeps dirt out.

Points to check:

• Size: listed as 3 or 3.5 inches; confirm that it matches the intake pipe or coupler it joins. A sudden step in diameter just behind the stack gives back part of its benefit.
• Space: the element needs clear air all round, away from the bonnet, radiator and inner wing.
• Air source: in an open engine bay a pod breathes warm air. A heat shield, an airbox or a cool-air duct keeps the intake temperature down.

Clamp the pod onto a clean pipe and support the pipe if it is long, so engine movement cannot work the joint loose. On an engine with an air mass sensor, keep a straight run ahead of the sensor and check the mixture after fitting. Clean the element as its media type requires, and refit it only once it is fully dry.