Ran open airbox today

[DAC]

I've never been convinced air intake ( filter mods) would make much of a difference, would engineers really put out a design that has an engine running out of air? And if so, I would think it would only run out of air at max RPM, when it needs the most air, not during normal operation when there should be plenty of air.
Just me, I know others have different opinions and experience.

This has always been my suspicion as well. I have seen, somewhere in the webz, that airbox mods and filter types don't add any benefit. Certain "high flow" filters may actually allow more dirt into the intakes.