Butt Dyno, am I right?
 

Been testing 2 airpods,
One with a ~3" length, thick rubber intake curve pipe, that connects to the carburetor; and the other with a standard 1" intake pipe, that comes stock mounted on any pod air filter.

In my tests on the same day, though with a temperature drop of about 5-10 degrees between rides, it seemed to me that the pod air filter with the longer intake curve pipe, the top end was suffering somewhat (took longer to get up to 60MPH), but I had the impression that the mid range (3-6k RPM) was somewhat better (seemed to have more torque).

Am I imagining this, or is there a science backing up this theory?

Could be imagining it, could be that the longer pipe is improving the flow velocity and/or stability of the intake flow.

I chased some performance issues when I went to pod filters on my '79 XS11 Special many years ago. Wound up discovering that the intake boots that came with my filters were blocking some of the metering ports on the filter side of the carbs:


https://caferiders.proboards.com/thr...special?page=4

A longer stack allows the airflow to be straighter as it passes through the venturi and atomizes the picked up fuel. Same reason I made them for my Corvair project. Will I notice a difference? Probably not. Is it "working better"? Most likely.
I've always done what my butt dyno tells me. I can't afford a real one!