A little experiment to find new turbine with better performance.

Sadly I have nothing to measure airflow in any values.

But I found out that balancing test piece on an air using knife edge may give comparable results.

So the winner is:...........
ta-da-dam
v3 version (Radial blower one) - see update below

P.S. v6 is original (60mm fan), which after cutting top solid surface became v5

UPDATE:
printed 2 more fans and we have a new winner.
My measuring piece have reached its limit, so I moved to wooden ruler.
So the best version on 04.2020 is v8 = turbine-forward-v2 by cimo
v7 by DrRalph (modified) is better than v3 on old test piece, but bit worse on wooden.
And v7 has most finest rotation without virbrations.

A little bit sanding is required if you want to pull it back out.