Maybe worth creating a small table - hp one variable (lets say 200,250,300,350,even 400) and best ROC speed the other variable (90/100/110)
Assuming we get a flight sometime soon we then then fill in some of the missing information quickly (what is the actual hp)
That's a good idea.
So we see that of course at the lower climb speed the rate of climb increases, since we have lower drag at the lower speed. But is 90 knots really feasible as a climb speed for this airplane, considering that he rotates at 90 at a fairly light weight?
I'm including here the Climb Calculator I worked up to get these numbers. As mentioned previously, you have to have some idea of the airplane's drag in order to try to estimate its climb performance...since the amount of
excess power available is going to depend on how much power is required to overcome the drag in the first place.
In this calculator, I continued with the SR22 as the known quantity. We use the Cdo that we extracted previously with the drag calculator, as well as the Oswald number, which is a key part of the induced drag. So since we have established these key parameters already, the only thing we don't know is the prop efficiency at our climb speed.
Knowing that the rate of climb is 1,304 fpm at SL ISA, we can simply iterate the prop efficiency until our calculated rate of climb matches the book number. It turns out to be 0.615. You can do this with your Saratoga or any other airplane for which you have solid data.
I've included below that the same computation for the Raptor climb rate. Here we estimated the Cdo at 0.03 and the Oswald number at 0.8. Both of those may in fact be a little generous.
The numbers really speak for themselves. Carrying that much weight, this airplane does in fact need about 350 hp to even see 1,100 fpm at 100 knot climb speed. And that's still less than the Cirrus.