EuroPilot82

I have a Great Planes Extra 300SP (color scheme Blue/Yellow) from towerhobbies.com. I am looking for advice on prop size to get the max power for 3D flying. I am currently running 15% nitro fuel. I am semi-new to nitro engines and I am located in Germany so options for fuel are extremely limited. I have made multiple flights with this plane and it is amazing in the air. I am currently using a 13 x 6 APC prop. I am open to any suggestions and advice. This is my first post and I have attempted to add a picture of the plane. Hope it works! Thank you for taking the time to share your experience and info.

extra300crazy

I have the same plane (love it! ) powered with an O.S. 72a four stroke engine turning a Xoar 13/7 @ 8800 rpm. I could get more thrust with a Xoar 14/6 with a slight reduction in speed. I'm also using Cool Power 15% for fuel. Hope this helps.
Karl

EuroPilot82

Thanks! I would like to have this plane a bit more 3D like but I guess I am on the right track with the prop size. I might change it out to a different pitch in the near future. Thanks!

extra300crazy

With a .91 four stroke possibly a 14/6 or 15/6 would do it. Larger diameter / smaller pitch prop = high thrust lugging power for 3D flying.

EuroPilot82

Thanks Extra300crazy....I will try it out. I have to order them in. I am located in Germany so everything like that has to be shipped. Europeans like electric planes and very few have nitro anything.

extra300crazy

Love the smell of nitro in the morning !
Karl

KC Air

I just finished building this plane, with a Saito FA82. The maiden flight will be in the next week or two, I hope. I asked around, and the consensus is APC 13-6 or 13-8. I am going to maiden without pants.

I am with Karl.. the smell alone is enough to want to burn nitro. Not to mention, airplanes should make noise!

extra300crazy

All of my four strokes seem to prefer a 7 or 6 pitch. I'll bet that a 14x6 would do the trick. I have an Aeroworks Extra 60-90 260 that I power with a O.S. 81a with a Zoar 14x6 at 9000 rpm, and it flys geat. I'm running an O.S. 72a in the GP 300SP with a Zoar 13x7 at about 9000 rpm and it flys good as well. For 3D i would try a 14x5 on the Saito 82. I put 2 1/2 wheels instead of the foam 2 1/4 ones and had plenty of room in the wheel pants without any issues on our grass field. Lose the foam tires as they can distort, catching the wheel pants and ripping off the gear. I've seen it happen more than once. The throws given in the booklet were perfect for the first flight, although I increased the low throws by 15% afterwards for better aerobatics. I've been flying mine for almost the whole year, and could'nt be happier!
The 300 series Extras fly noticeably better than the 260 ones. Less coupling I suppose.
Karl