[Gunner]

Foam filters are awful in terms of flow. They're for offroaders who can't have a filter collapse or plug up because it gets wet or muddy. If they're thin enough to flow like paper or oiled gauze, they're probably too porous to offer much protection. I can see limited race use where you want to keep pebbles, nuts and small birds out of your intake but put up with more grit getting to the cylinders.