Originally Posted by
SrTelemaster150
All they can do is estimate speed @ the static RPM. How can they predict what an SE-5 & a P-51 will achieve for top speed @ the same static RPM W/O the drag factors?
That's an entire different set of calculations that you have to do, and even then there are dynamics which can change things.
The only way you know for sure is put it in the air and see what happens.