purpose of shorter pump vaines

[Goose]

im tryin to understand these pumps and been doin some reading on the skat pumps.they say that the 12 and 14 vaines are 1 in long and that the 6 vaine is 3in long can someone explaine to me what the reason for having shorter vaines would be.Im kicking around taking 1/2in off the back of my vaines in a oem yamaha pump,would this be a good or bad idea
Thanks

 

[#ZERO]

The shorter vanes have less hydrodynamic drag but it require more of them to equal the same strength.

That's why the 12-vane setback pumps are the most sought after.

 

[Goose]

would cuttin 1/2 inch off be any gain

 

[waxhead]

No i think you would lose to much water straighting effect

 

[WFO Speedracer]

I would think the angle of the veins would have to be changed as well which really can't be done.