ORIGINAL: richardgerardi
She maiden this past weekend, 100mph not even close. I think 65 at most. Will play around with different prop sizes and maybe a tune pipe see what happens.
For the Kougar......
with the stock muffler, go with a 9x7 prop. Allow the engine to turn up a little.
Add a jett-stream muffler to the 46AX
9x7, 9x8 prop, ground peak rpm around 15,500 - 16,000 is what you want.
That is about the best you will see speed wise on the Kougar (unless it has retracts in it)
As noted, the plane has a thick wing. But that is one of the reasons it flys and lands so great. Also has a lot of frontal area. But the Kougar is a classic for a reason ..... good looks, great flying, and just a great sport plane.
MJD covered the "prop speed" subject well. Best thing to do in most cases is leave the calculator in the drawer. Aircraft performance is a balance between prop/engine/aircraft/pilot. Pitch x RPM does not tell much of a story.
Brief example I have posted before.
We know that a well built, well trimmed 424 sport Q-500 plane can reach
level flight speed of 120mph (time, radar, air data confirmed on a number of occations).
That speed obtained not on the race course, but in extended level flight where turning is not involved.
Q-500 is quick.... semi-low drag, but very basic, boxy ..... so it can be considered a fast sport plane.
Powered by a TT40pro, stock, stock muffler, turning a 9x6 apc prop, at ground peak somewhere around 16,500 rpm.
We also know the engine can get up around 17,000 rpm in flight.
Using that, you can back out what the "pitch x rpm" speed would be.
You can see the disconnect.