I use the set-up Brenner mentioned in the Osiris. But I am using a Neu motor. And I have cut 1/4" off each tip of each prop. I fly about as big and fast as they come and in a Masters pattern, even in wind, I have never put in more then 4200. Usually it's 3,800, 3900. It is a bit higher then a single prop, but oh, the benefits!

I am going to try the 22x18 on the front again. I tried it a while back and didn't think it offered any advantages, but I think I need to try it again.