I have been running a Dynathrust 18-10 on my ryobi 4 stroke and only getting slightly above 5000 rpm. I then ordered an APC 18-8 to try to get the rpm up a little. The only problem is that the APC looks horrible, like a pointy dagger. I've used the 10-12" size and this looks way different. The tip chord is under 1/2". How can this produce much thrust? Is this prop made for large, high prm motors? I was informed that the Dynathrust weren't the greatest props. Any truth to that? Does anyone have any experience with this prop?[]

Any help would be appreciated.
Doug

APC must be doing sonething right, we use APC props on our G62 and GT80 race planes..
The GT80 powered formula one 100 inch GR7 and Kelly race planes clock almost 180 mph on radar..They turn 11,500 rpm in the air....Pictures at usrainfo.org..Don't forget the www.

Darn it Doug, You got the pattern APC prop. They make two flavors. Pattern and Wide blade. Your correct in that the prop you own is for high rpm apps, the wide blade is to be used in our rpm range. You should gain quite a bit rpm, 300 and maybe as much as 800 over the Dynotrash prop, on the wide blade of course. That narrow blade one isnt going to make the thrust you want at the 4-strokes rpm range. BTW, the ryobi 4-stroke ignition coil has a buit in rev limiter. I'm not sure where its set to, someone else here might post it. So if you do find some high rpm that the motor spits and barks at, you know why. I love the APC 18-8 and 16-8 wide blade that I have. I've flown them on my ryobi and homelite conversions and the make tons of thrust over the DT props I have. I do like to use the DT props on scale planes but when the plane needs a power prop, APC wide blades are what you need.

Thanks Piper,

I had this feeling that something went wrong with the prop. I'll have to nag my LHS to get the wide and exchange mine. Luckily he's a very nice guy and RC'er also.

This is why I love RCU.
Doug

Thanks for explain on the props. Often wonder why the APC I ordered where so narrow tipped.
A sticky on prop styles would be benefical for those of us without LHS!

Go to the APC web site and see what they have listed in the prop size you think you need. You can order direct form them.