I have been running 11x6 props on my gms .47 and my planes seem to fly real well. My problem is that someone tacked my engine one day and I was pulling around 10,500rpm on the ground, and I have noticed that if I try to pull my freestyle into a hover the engine will start to bog down. Would a 11x5 be a better choice for this engine, the plane is plenty fast so I am mostly concerned about lower end thrust.

12.25 X 3.75 APC

Enjoy,

Jim

That rpm figure for your GMS seems on the low side. It should do upwards of 12,000 with the 11x6 MA or APC.

An APC 12.25 x 3.75 is a good choice, and should do at least 11,500 rpm. Another good prop for your application is the APC 12x4, which should easily do in the mid twelves.

Hmm, I run 15% nitro, so maybee I didnt have it tuned in just right.

I have tried the 12.25x3.75 APC props on my GMS 47 and Tower 46 and they do work fine, but seem to spool up slower than I like. My all time favorite prop for these engines is the 11x4 APC, spool up time is very crisp and the rpm is much higher.

Well if your getting away with an 11x4 without over reving or over heating the engines, I should definetly get away with an 11x5. By the way I also have a tower hobbies .46 and still havent figured out which has more power. The gms seems to be closer to holding the hover but it starts to bog down, go figure.

Went flying today with a 11x5 prop on my gms .47 and it was a perfect fit. My top speed seems a little slower but my low end performance has gone way up. I can hover all day long now.