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-   -   Performance RV-9 (https://vansairforce.net/community/showthread.php?t=58513)

tc1234c 07-09-2010 06:17 AM

Following is from four years ago. I did the test at 8,500'. My propeller is placarded not to run over 2,600 rpm.



Configuration at the time:

O-320, 160 hp, carb, 2 mags
Standard fixed pitch Sensenich propeller: 70CM7S9-0-79
empty weight: 1084 lb
polished aluminum, primer on fiberglass parts
wheel pants and fairing on

Now I usually cruise between 8-10k, at 65% power it does 140+ and burn less than 7 gph. Since conditions are different I can not give a single performance number. I know other 9As with better performance than mine. Mine is a little heavy and not perfectly built.

PaulR 07-09-2010 07:26 AM

Catto Pitch?
 
Tony,
I'm curious about your speeds. I have a Catto 3 blade ready to go on my 9A and am wondering if you have Craigs' recommended pitch for a 9A with 160HP or did you have him do someother pitch? I can't remember what it is off the top of my head but he was sure when I got mine that it would generate at least Van's numbers.

Thanks

apkp777 07-09-2010 07:41 AM

Quote:

Originally Posted by PaulR (Post 448657)
Tony,
I'm curious about your speeds. I have a Catto 3 blade ready to go on my 9A and am wondering if you have Craigs' recommended pitch for a 9A with 160HP or did you have him do someother pitch? I can't remember what it is off the top of my head but he was sure when I got mine that it would generate at least Van's numbers.

Thanks

Paul, I told Catto what I had he said he would pitch the prop for 191mph. I am no where near that. I have sent him a message and and waiting on his reply.

339A 07-09-2010 09:45 AM

My Last Test
 
Hi Tony,

I sent mine back to Craig last year for a re-pitch. I did a WOT GPS test before and after. What I can say is that it didn't change.... When I got the prop back and tested it using the three way GPS method, the results were the same. 161 kts at 2700 ~ 2730 RPM with the DA at 11,500. (don't currently have % power #'s coming soon) My fuel burn is in the same vicinity, though a little less at the higher altitudes.

I would agree with you about the climb pitch. It climbs very well. Something I've noticed flying with my CS friends (6A's). If we are in cruise they will leave me behind unless they pull some power. If we start into a climb configuration (to get over the rocks) I will gain on them and pass them unless I pull some power off! How much of this is wing efficiency at higher altitudes or the prop? I'm not an aerodynamics expert so I can't say.

The Catto still remains about 5 kts faster than the original Sterba prop. I do think it could be pitched more. When I'm at sea level I've got almost half of my throttle pulled... fixed pitch props are always a compromise.

Quote:

Originally Posted by apkp777 (Post 448556)
Today I took my plane on a speed run. At 2700 RPM and 8000 DA, I was about 3/4 throttle 71% power and 151 KTAS (174MPH). I feel that this is a bit slow. My fuel burn was about 8.2gph. I had bkn cumulus clouds at my alt so I had to maneuver around a bit. I am going to re-run, but with about 1-2" of throttle left I am thinking that my Catto prop is pitched more for climb. I will say this plane climbs REALLY well. 1900 FPM is no problem and if I climb at Vx I will see 2400. I'd rather have top end though.

Anyone have any thoughts on my performance numbers. Seems slow? I can live with it, but I'd really think that I could get WOT at 8000 DA and be at 2700 RPM?

at 2400 RPM I am about 135 KTAS 2500 about 140


MauiLvrs 07-09-2010 11:16 AM

Quote:

Originally Posted by dedgemon (Post 448580)
You ought to see it climb with the constant speed.:D

I did I did ... AWSOME :D

apkp777 02-16-2011 08:35 PM

I just received my re-pitched prop back from Catto. Here is a current screen shot. This was at W.O.T. 8kDA and full fuel and just myself.



Here is the screen shot of prior to the re-pitch. Notice the high RPM compared to the current shot.


apkp777 02-16-2011 08:40 PM

Here is a picture that most pleases me. I switched back to KTS for my airspeed. Notice the 156 KTAS at 2550 RPM. Before my re-pitch I would have to run 2750 to get that. So far so good. I will try to post some pictures on my blog later of the nickel leading edge retrofit.


kentb 02-17-2011 09:47 AM

Tony, looking great.
 
I like that the first two pictures show that before you were using 11.3 g/h and the after pictures shows that at the same speed you were using 8.1 g/h.
I know the flight conditions were a little different, but it is looking good.

Kent

apkp777 02-17-2011 09:54 AM

Quote:

Originally Posted by kentb (Post 514469)
I like that the first two pictures show that before you were using 11.3 g/h and the after pictures shows that at the same speed you were using 8.1 g/h.
I know the flight conditions were a little different, but it is looking good.

Kent

Hi Kent,

Yep, the first photo I wasn't leaned at all. One of the natural by-products of turning 2900 RPM was high CHTS and EGTS. It was also a hot day. Re-pitching my prop in part was desirable so that I could see my temps come down. So far, so good for that.

I am thrilled with my RV-9.

tsneidin 02-17-2011 01:22 PM

Thats great Tony, now show us your nickel leading edge on your prop.


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