Airbox vs No Airbox

Years ago I was tuning a Honda 800 V-twin, trying to set the sync and mixture on the two individual carburetors…with no luck. It would stumble, fall flat or even die when adding throttle, unless I messaged the throttle to get higher RPM. After some reflection, I decided to install the airbox and filter, and voila, it throttled just fine. Lesson learned.

As a result of that incident, I always install the airbox and filter when tuning VFR carbs, but yesterday I decided to recreate my experience and ran the engine sans airbox. The video below shows the results.

Back in the day, we would routinely swap our inline fours' airbox for individual pod filters, and the bikes ran just fine, so my logical brain doesn't easily compute this phenomenon, but there's some science behind it, and that science began in the motorcycle world during the 1980's. Can we still make "modern" carburetors like ours (or fuel injection) run without their engineered airboxes? Yes, but it would take some aggressive jetting tuning, and we would likely be defeating the performance objective by degrading the torque/HP tuning that the engineers worked so hard to achieve. Here's a brief explanation from Kevin Cameron:
https://www.cycleworld.com/what-is-secret-importance-motorcycle-airbox/