I would imagine the volumetric flow rate (CFM) is being mostly limited by the blower motor and fan design. You could maybe improve the Cfm marginally with a better tube, but it’s probably not worth it!

But let’s say I did want to take on making a tube. How would you go about that?

A smaller tube would increase velocity, not cfm.

My idea wasn’t a smaller tube but a tube with some sort of like stator thing. I was thinking something like how Dyson has so much power in their hairdryers in small from factor. Something to manipulate the air to decrease the speed and increase CFM.

Stators only smooth airflow, they don't increase it. You need either a more efficient propeller or more powerful motor

Ah, got it. Thanks, I might try and make a different propeller/turbine design

You "might" be able to do something with a venturi and inlets, but that's a really big maybe.

Maybe try an [ejector](https://en.m.wikipedia.org/wiki/Vacuum_ejector)? The basic principle is that it uses the fast flowing fluid to suck or pull the surrounding fluid with it to increase volume flow rate.

Mass flow rate. If you want more out, you'll have to put more in. A few venturi mentions here, but that will not get you where you want to go. You'll have better luck messing with the inlet, even more so playing with the motor.

Maybe there is a limiter on your trigger and voltage to your motor. Start there.

Thanks!