Originally posted by fatflyer41
Seanychen,
I see you are estimating that ThrustHP is 30% or so on the optomistic side.
It seems a lot of people think the program is very optomistic. Do any of you experienced engine gurus and ThrustHP users have a different estimate of how optomistic? Anybody ever test specific static thrust with a scale and compare it with ThrustHP?
The reason why I said it's about 30% over optimistic is from real-life correlation. I had a 6 lb GP Extra 40 ARF w/ Saito 72 turning 13x4W @ 11000, and it will hover at near full throttle. ThrustHP says I should have 10.37 lb static thrust, which is 1.7 thrust-to-weight ratio. But it feels like I have a 1.2 thrust-to-weight ratio.
Another example. My 7.5 lb UCD w/ Saito 100 swinging 15x4W @ 10300 rpm, according to ThrustHP has 2.1+ thrust-to-weight ratio. It flies like 1.5 thrust-to-weight, because its vertical acceleration looks like 0.5G, w/ drag accounted for.
Aerosplat did some experimental analysis, using Saito 100 swinging 15x4W @ 10300 rpm, pull like 11.5 lb. of vertical tow weight.