I discovered the(IMO) best prop for Sa150 is APC 17X6. I used a tach when a Zinger 17X5 wood prop was on using 30%Magnum fuel, was getting around 9K. When I went to APC 17X6-to my surprise, it turned up to 9.7K. I couldnt believe the readings but its true. The Zingers & other wood props are thicker air foils and have a little more chord-guess thats why a 17X6 runs faster than a 17X5. I did drop the R's back to about 9.4K so it won't lean when hovering.