ZDZ 80/ H9 SUKHOI

[ilovemetro]

Hey, I have a zdz 80 on a hangar 9 sukhoi, probably somewhere in the 24-25 pound weight range, swinging a 26x8 bambula,not on cannisters, and im pretty sure a pitts bisson muffler, i also have a 26x8 zdz prop... the engine runs good, but when im in a torque roll, it has no vertical out, im at half throttle maybe a little less for the roll, and i push it wide open and it has a climbrate of a centipede on a tree, any ideas on how to get more power? i.e. props to run/ tuning?

[Pilot24J]

I have the exact same combo - have had it since the H9 Sukhoi first came out. I've always run a Menz 26-10S prop on my ZDZ 80. It pulls out of a hover/torque roll just fine. I believe my plane weighs about 23 1/2# so if you are at 25#, maybe that is the difference. The only complaint I have with the ZDZ is a dead spot on the throttle right around where you need it to hover. I would try a Menz 26-10 and see if that helps.

[ilovemetro]

alright thanks, my dad was thinking about moving to a 10 to see if a little more prop would help out, we'll give it a shot.

[Bat Fastard]

I've had 2 ZDZ 80's and the best prop I've found is the mejzlik 26-10. 6300-6400 rpms with a stock supersonic muffler. I just bought a Vess 26-A to try out. I'll let you know the results in a few weeks.

[Jaybird]

The Mejzlik 26-10 is very good but the 26a Vess blows it away in pulling power.
I have tried a 26-8 Bambula and thought it sucked. It made a lot of noise but wasn't going anywhere.
Brian

[ilovemetro]

alright thanks guys.

[tec]

	Quote: Originally Posted by ilovemetro
	Hey, I have a zdz 80 on a hangar 9 sukhoi, probably somewhere in the 24-25 pound weight range, swinging a 26x8 bambula,not on cannisters, and im pretty sure a pitts bisson muffler, i also have a 26x8 zdz prop... the engine runs good, but when im in a torque roll, it has no vertical out, im at half throttle maybe a little less for the roll, and i push it wide open and it has a climbrate of a centipede on a tree, any ideas on how to get more power? i.e. props to run/ tuning?

Is your 80 the standard version or the super 80? I have the Cap 232 and I'm looking for a engine to replace the 80 Twin it came with. I thought the Super 80 would pull the snot out of it? Maybe the BME 115 is the way to go?

[dick hanson]

The Pitts Bison muffler (the one with rolled edges) is quiet --at the expense of a pretty good power loss.
The larger in cowls make a good bit of difference
as for engine choice - - it's up to you . The 80 Super with the new Suprsonic muffler and the ZM 26x10 does produce at sea level and at 4350 ft 7100-7200 . static and upwards of 8400 in the air .
the prop is a thin , rather wide center blade and very good for 3D stuff. This prop does run a few hundred rpm faster than a Mejzlic same size but I like it better for instant hover /recover.

[juanes1969]

Dick, what prop do you recomend for the ZDZ80RV (normal 80) with a supersonic muffler?
Would a mejzlik 26x8 produce more that 7000 rpms on that combo?
Thanks
John

[TheTank]

	Quote: Originally Posted by dick hanson
	The Pitts Bison muffler (the one with rolled edges) is quiet --at the expense of a pretty good power loss. The larger in cowls make a good bit of difference as for engine choice - - it's up to you . The 80 Super with the new Suprsonic muffler and the ZM 26x10 does produce at sea level and at 4350 ft 7100-7200 . static and upwards of 8400 in the air . the prop is a thin , rather wide center blade and very good for 3D stuff. This prop does run a few hundred rpm faster than a Mejzlic same size but I like it better for instant hover /recover.

I agree with Dick, if you have the muffler with the rolled tips, and want to increase performance, cut 1/2" off the bottom of the stacks. Also, get rid of that Bambula prop. Put a Menz 26x8 or 26x10, a Vess 26A, or a mejzlik 26x10 and you will notice a difference. The prop Dick mentioned also seems like it could be a good combo with the narrow blade for 3D and quick spool up. I ran the regular 80 on my comp arf 2.6m at 23.5 pounds dry and it flew great. That regular 80 really pulls like a tractor when propped right. I cant imagine the super 80, its gotta be mad power.

[TheTank]

	Quote: Originally Posted by juanes1969
	Dick, what prop do you recomend for the ZDZ80RV (normal 80) with a supersonic muffler? Would a mejzlik 26x8 produce more that 7000 rpms on that combo? Thanks John

I know with my Menz 26x8 with a cannister exhaust, I spun 7300 on the ground at sea level. When it unloaded in the air, the engine screamed. It was mainly a 3D prop for me as I felt the engine spun up to high when flying fast or flying sequences. For that type of flying I went to a 26x10.

[TheTank]

If you ever wondered have much props diameter and pitch affected the output of thrust (static), here is a quick thrust calculator that had a selection for Menz (as well as others) props. I used something similar to this when I was testing props for my 2.6m extra. When this caculator was created and tests were done, the found very little change in thrust when changing pitch due to other factors (RPM change, Blade cavatation/stalling etc.)

http://www.coloradogliders.com/stati...calculator.htm