mautrevinogarza

Mauricio Treviño Garza
Monterrey, Mexico
Jett Engine SJ-50LX powered Phoenix F-20 ARF

It is pretty fast
10% Nitro
Prop APC 10 x 7
6th Tank
248 kph - 154 mph

I haven't done any modification yet, but just be concerned about flutter.

vicman

My Feedback: (10)

Good show Mauricio!

davepa

Hi guys I plan on ordering a phoenix F20 and want to go with an o.s. engine but cant decide if I should get the 46 ax or the 55 ax.This will be my first fast plane so im thinking the 46 might do me fine.Any suggestions. Thanks

YUKONFLYR

My F-20 likes a 10x7, I have used a 9x8 but did not notice much difference. Given you choices I would go with the bigger one

dorset john

I have a Webra .55 in mine with a mini-pipe. It's quick but not outrageous - I would advise going for the .55 and a 10x8 prop.
You may get near to 100mph in a dive, but this is not a clean enough plane for more. P.S it flies like a trainer at low speeds, I have even tried (unsuccesfully) to get it to 3D without any really scary moments.

liquid_TR

Get an 55AX, buy a bolt-on tuned muffler for it (ie ultra-thrust or Jett muffler), put a 10x9 APC or modified 9,5x9 prop on it.

Clip the wings 11cm from each end (last rib on each wing)

enjoy 125 mph of level flight..

takes off and lands without any difference..

If you can build in a retractable landing gear system into it, you will gain a LOT more airspeed. (probably 25+ mph)

Make sure you reinforce the vertical stabilizer.

edit: typo on the prop size.

bob27s

My Feedback: (19)

Either the 46 or 55 is a good choice.

Adding the tuned muffler really makes a huge difference in power and aircraft performance. The plane is large and a bit draggy.

The OS 55AX with the jett-stream muffler turns an 11x6 or 10x8 up around 14.5K rpm... and that is the real sweet spot to shoot for.

OS46AX with the Jett-Stream - 9x7, 10x6, 10x7 target anywhere between 14,000 and 15,000 peak ground rpm

Bob

dorset john

Hey Bob, I keep seeing rave's about the Jett mufflers - without giving away any secrets please can you tell us how such a short muffler boosts power so much? Conventional wisdom seems to call for a couple of feet of noisy peaky tuned pipe.
Then please can you tell me how to get hold of one in the UK?

bob27s

My Feedback: (19)

Nothing really secret about it...

It is a fractional wave tuned pipe. The shape creates a folded configuration. Thus the compact size.

Gives about 85% of the boost available from a full-size tuned exhaust. Tends to provide a broader tuning range too.

The mufflers are available for order from the website. Dub ships to the UK and around the world on a weekly basis.

Also... since you are in the UK ..... Weston makes pretty darn good tuned exhaust products. Worth looking at.

dorset john

Thanks for the Jett info - I don't want to diss Weston but the Genesis one-piece mini-pipe I fitted to my Webra .55 last week barely made any extra revs - It did give me an extra bit of mid-range stonk and changed my main jet setting from about 4 turns out on the stock pipe to 1 turn out on the mini-pipe (I suspect the mini-pipe stinger is too restrictive - giving too much back pressure). I also needed to file out the mini-pipe manifold by about 50% to match the port shape on the engine.

davepa

Thanks for the suggestions.I guess i'll go with the 55ax with the jett muffler but will the extra weight cause a cg problem and how do you reinforce the verticle stabilizer as suggested by liquid TR. Thanks guys

dorset john

CofG will probably be spot-on (there is a slab of metal pre-installed in the tail).
The stab can be reinforced by drilling a 2mm hole just in front of the stab upright and inserting a 2mm carbon rod and cyano'ing it in. The rod sticks out the bottom of the stab and is inserted in a matching hole drilled in the fus' stab base.
Do use post type rudder horn to account for the twisting motion. I can manage flat-out knife edge loop with this configuration.

bob27s

My Feedback: (19)

That is actually not necessary ... the Jett is the same way. Muffler inlet size and exhaust outlet size is actually part of the design.

dorset john

Oh dear, that throws my perceptions of gas-flowing out the window. Now the only reason I can see for the exhaust inlet to be smaller than the motor exhaust port outlet is to try and trap sucked-out fresh fuel in the motor exhaust port ready to catch the reflective wave from the baffle and shunt it back into the cylinder. I may have been too hasty with the needle files, would you suggest I re-introduce the restriction by adding a constricting gasket maybe made out of dural sheet? I don't want to pose this question to Alan at Weston as I suspect I've already blown my warantee.
P.S I also drilled out the blank tube insertion which restricted the stinger in my Weston pipe - now have a much less sensitive main needle and a lovely howl. Also found that now a 10x9 apc will pull 13,600 on the ground (same as 10x8 previously and more than 11x7). Webra claim maximum power for the .55 at 17K - but a smaller prop (e.g 10x7 or 9x9) just makes a lot of noise on the F-20 and doesn't add speed or responsiveness. Any suggestions?

yukonpete

My Feedback: (4)

First thing, thanks YUKONFLYR for your control throw settings and help at the field last night

I maidened my F-20 last night and I couldn't be happier. I used YUKONFLYR's settings and the plane was easy to fly. I only needed 1 click of left aileron trim and 8 clicks of up elevator trim. My engine is a Super Tigre G51 with a 10 x 7 Master Airscrew Smiter prop. My CG is at about 145mm.

YUKONFLYR

Nice............................[sm=thumbup.gif]

That makes two F-20's up here in the Yukon ripping it up.........

Just gotta get you that Rossi we have been talking about, give that t/shark some attitude...................................like this [sm=48_48.gif]

vicman

My Feedback: (10)

[8D]

kom

i have a rossi ral 40 available - would it be enough for this plane ? if yes what prop is recommended

dorset john

Added wing-tip ASRAAM missiles to my model. Looks good in the air and make a nice whistling sound.
Standard wing-tip balsa is thick enough to drill and tap 5mm and use cyano to strengthen thread.
Missiles are 20mm balsa rod covered in aluminium foil with fins made from plastic sheet and inserted into sawn slots.

YUKONFLYR

Nice Missles!

What kink of Motor is that.....Webra?

Kmot

My Feedback: (24)

Yes indeed, the missiles look sharp on there!

dorset john

Powered by a Webra .55GT and a Genesis mini-pipe from Weston UK. Good shrieking combination without being offensively loud. 10x9 APC prop.

KINGX

Hello to all F20 fans!

I have a question: how fast is this plane in stock configuration and how does it compare to other speed planes like the revolver, sundowner, etc?....

I fly pattern aircraft, and if i open up the taps a little bit on a pattern model, they really go fast. Do you think that a 50 size pattern plane can be faster than an F20? I am asking this because pattern models usually have thinner airfoils than the F20 , thus the potential to fly faster at level flight.

Thanks.

vicman

My Feedback: (10)

You would be correct. I have flown a few versions of ARF F-20s with normal and good engines. Most of them are in the 105-120mph range wide open in a dive. An old skool pattern ship can do that pretty easily in level flight from what I've seen.

toro_0397

hi everyone.
my dad is going to give me a new plane, and i really like fast planes. i have three options right now, and i want to know which one do you think is the best one. the engine that i am going to use is an os 55ax.
right now i am flying a towerhobbies kaos with a 55 ax too.

f20 phoenix models.

strega phoenix models.

magic evo. vq models (i am not sure about it since it is designed for a .32 engine and i only have a 55 ax avaliable. i would apreciate any info about this plane.)

are these planes faster than the kaos?

any other suggestions please tell me. thanks alot.