hecilopter

hecilopter

Well Known Member
I have a newly flying -7A (N357RV) and have a couple of questions. I have an XP-360 carbureted with the 74" Hartzell blended airfoil prop, no fairings on, and I am seeing about 150 knots (~170 mph) true on the Dynon at about 3000 ft density altitude. Is this in the ballpark of what others are seeing? Am I going to pick up another 25 knots (30 mph) after fairings and at 8000' density altitude? This just seems slow to me.

Also, when taxiing I have an annoying vibration in the brakes. When there is no pressure on the brake pedals, the brake caliper unit "floats" about 1/6" or so and makes an annoying rattle. Has anyone else experienced this? Thanks in advance!

Rusty

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without fairings in our RV6a @ 8000 tas was only around 170mph ... we now get 198 mph to 200 mph fully setup. :cool:


note we figured out that we would get a better speed when we couldn't get the engine up to 2700 rpm @ 8000 without the fairings.
 
n468ac said:
without fairings in our RV6a @ 8000 tas was only around 170mph ... we now get 198 mph to 200 mph fully setup. :cool:


note we figured out that we would get a better speed when we couldn't get the engine up to 2700 rpm @ 8000 without the fairings.
Click to expand...


2660 RPM (should be just less than 75% power at 8000) and 100deg ROP
 
Hey Rusty, You're doing fine. Expect about 20 mph increase with the fairings and pants on. I run my 180 hp 0-360 at 2400 rpm at 8000 and get over 200 mph at gross. Do consider the wooden dampers on the main gear legs. They really smooth out the gear vibes. Paint and cleaning up the fiberglass will also help a little. Looks Great! Enjoy!

Roberta
 
Thanks for the responses!

I got to about 5500 ft density altitude today and the true airspeed bumped up to 157 knots. I was flying at 25"/2500 power setting. I can't wait to get the gear leg fairings/wheel pants on! I am going to do the wooden gear leg dampeners (thanks Roberta!) and maybe my brake caliper rattle will go away.
I love this thing!

Blue skies and tailwinds,

Rusty
 
re: wooden dampeners

I'd wait until you get the pants and leg fairings on before you consider the dampeners. I had a bit of the main gear shakes until I had the pants on - I guess the mass of the pants was enough to change the harmonics of the gear.

I never did install the wooden dampeners - if you want mine you can have em cheap. :D
 
To help the brake rattle, you might consider putting antiseize compound on the guide pins for the brake caliper. That is what we do at out shop, it keeps the pins from stick, which MAY help your vibration during taxi.
 
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