Below is my version of a filter airbox. Inspired by the offering from Van, I expect this one to be more effective. Shown below is the plug (MDF, tooling foam and glass), and the resulting mold half. Shown for perspectice is the 2x10x14 air filter element which has about a 50% increase in filter area over the previous cone style element. With the generous area and resulting low velocity, I expect essentially zero loss with this filter. Will have to flight test to confirm, but I'm betting the engine won't even feel the filter in practice. Next step is to pop out a pair of CF housing shells and bond them together as an airbox.