ORIGINAL: ntsmith
the 14 X 6 was seen to be used in a write up on the very similar ASP91 so thats how I come to choose that for a starter.
The question is then. Would a 13 X 7 or 8 be better. Certainly with my Venus 40 a 6" pitch was jsut right and more pitch meant it flew faster but lacked the power in the up lines. I guess the same is going to apply here.
I will try the prop I have and see how it goes. Just get used to the plane at first for a good few flights any way.
Couple of weeks away I guess with the speed of my building (assembling!)
Most of the people I fly with like to use a prop that keeps a 91 four stroke between 9,000 and 10,000 rpm static. The 14x6 seems to do that on Magnum, OS, and Saito 91s running 15% or less nitro in the fuel. I think a 13x7 would allow excess rpm and a 13x8 would turn numbers similar to the 14x6.
The Javelin is very sleek design. The 13x8 would likely do as you suggest; more speed but less vertical power than the 14x6. You may like the 14x6 so much you never even try a different size, and there's nothing wrong with that.
My brother and I have 91 four strokes on 3 planes each; all running 14x6 props. They pull great, go fast enough for us, and slow down well for landing. We've never tried different sizes because we are happy with what we have.