Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Viper500 Tips Before I maiden it ?

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Old 07-17-2013, 01:19 PM
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Default Viper500 Tips Before I maiden it ?

Gonna maiden my new Viper500 this weekend. Everything set exactly to the book. TT Pro .40 on a tuned pipe turning a 8.8" x 9.0" APC at a tick under 16,000.

Anything I should know before the maiden? And speed tips (other than putting a Jett in it, which I will be waiting patiently on doing once it gets maidened and sorted out).




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Old 07-18-2013, 01:03 AM
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Default RE: Viper500 Tips Before I maiden it ?

Go to the pylon forum. Read the sticky on the Viper before you fly. A wealth of information, tips and tricks.
Your TT.40 should be hitting 17,000 with a APC 9 X 6 sport prop on the stock muffler.

Good luck, go fast and turn LEFT!!!
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Old 07-18-2013, 02:09 AM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: NoOneFlysAtMyClub

Go to the pylon forum. Read the sticky on the Viper before you fly. A wealth of information, tips and tricks.
Your TT.40 should be hitting 17,000 with a APC 9 X 6 sport prop on the stock muffler.

Good luck, go fast and turn LEFT!!!
Will do, thanks. With a 9x6 it turns 17,200 on the stock muffler. Haven't tested the 9x6 on the pipe.

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Old 07-18-2013, 07:00 AM
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Default RE: Viper500 Tips Before I maiden it ?

I like your prop choice with the pipe.
You might want to loose the stock wheels and get some from Darrol Cady or some B&B wheels. The stock Viper wheels are bad to lock up and melt off when landing. You might get 3 or 4 flights with them and then you might get one.

Take off a little rich since you will lean out plenty in your first dive. Your plane looks nice, enjoy it.
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Old 07-18-2013, 10:24 AM
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Default RE: Viper500 Tips Before I maiden it ?

8.8x9 is a lot of prop for a .40.......[I can't believe it would unload very much].
With this much prop my first flights would be on 25% oil and read the glow plug before every flight.
It looks like a fast and fun plane, good luck with it.
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Old 07-25-2013, 03:53 PM
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Default RE: Viper500 Tips Before I maiden it ?

What was the end result ?
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Old 07-25-2013, 04:23 PM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: scoeroo

What was the end result ?
It flies! But I was having some carburetion issues. Made a 2-3 minute maiden flight, 1 medium speed pass before the carb issues really set in and I had to land.
It's hard for me to judge if it was a good flying ship or not. It's very lazy and I am used to ultra fast, ultra powerful surfaces so it obviously felt like a flying wet blanket.
But it was very easy to take off and land. Just had to judge your approach speed as she is a hot little ship.

I replaced the entire carb a couple days ago and ran it on the test stand. I will re-maiden her this Sunday and report back. But I think she will fulfill her intended purpose of running with the hot rods.

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Old 07-29-2013, 04:57 PM
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Default RE: Viper500 Tips Before I maiden it ?

Viper 500 full report....

Yes it flies, and it flies very well. Does have some interesting issues to resolve however.
New carb on the TT Pro .40 and she runs very good. I did my flights this past Sunday with the mixture a little fat. I am going to creep up on it, I don't want to lean it too much and hurt it.

It unloads just fine with 8.8" x 9.0" APC. I'd venture to guess that on it's 2nd flight after leaning her a little, it's running north of 100mph at this point and there is much fine tuning to go. Would like to get it on the gun and see for real.

Now the oddities. I have 3 rate settings on almost every plane. I have Low, High & HolyCrap nothing else works so I need all the throw I can get. I Take off on High Rate per the manual. No issues there. Climb out start gaining speed and flip it low rates and the nose drops and she starts downward! I was obviously caught off guard. So I flip it back to high and the nose comes back up and she flies level. So I decide to investigate further. I flip it up to Holy Crap and the nose instantly points upward and up she goes!

I have never seen trim changes when changing rates! This is something i will certainly look further into.

All in All, good flying airplane, pretty darn fast for the $$$ investment and while it does take a little creative planning to land nicely due to it's glide ratio it's a good sport plane. Inside loops, outside loops, rolls, spilt-s, immelman, and all the rest are pretty safe and easy. Doesn't have enough rudder authority to stall turn or spin, but that's okay I have plenty of ships that will perform those moves.

Now we go after more speed!
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Old 07-29-2013, 05:38 PM
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Default RE: Viper500 Tips Before I maiden it ?

Be very carefull doing spins. I've had several V tailed Quickies that would go into a flat spin, and not come out of it. They would spin right into the ground. I don't attemps spins anymore with any V tails. Good luck, Greg
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Old 07-30-2013, 11:19 AM
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Default RE: Viper500 Tips Before I maiden it ?

as CP said that isnt a good prop for that engine.

Just because its a Pylon Prop doesnt mean it will turn your plane in to a Pylon plane lol. Those Pylon Props work best above 18,000 on the ground. You would be better of with a 9x7 or even a 9x8 APC
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Old 07-31-2013, 09:35 PM
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Default RE: Viper500 Tips Before I maiden it ?

That change of trim when you flip your triple rate switch could quite possably be in your transmitter (? ) not the plane...
I encountered the same thing years ago with a Hitec Flash 5 Tx. so I sent the Tx. back and they "recalibrated" it...

Try a test while on the ground...watch for change in elevator trim as you flip the switch.
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Old 08-01-2013, 02:21 AM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: airraptor

as CP said that isnt a good prop for that engine.

Just because its a Pylon Prop doesnt mean it will turn your plane in to a Pylon plane lol. Those Pylon Props work best above 18,000 on the ground. You would be better of with a 9x7 or even a 9x8 APC
Really? Damn APC making me think it was a bonafide pylon plane with that prop. I guess I'll take that prop off and put a regular old sunday flier prop on it. But if I do that... can I fly it onSaturdays....?
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Old 08-01-2013, 02:25 AM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: proptop

That change of trim when you flip your triple rate switch could quite possably be in your transmitter (? ) not the plane...
I encountered the same thing years ago with a Hitec Flash 5 Tx. so I sent the Tx. back and they "recalibrated" it...

Try a test while on the ground...watch for change in elevator trim as you flip the switch.
Oh, I checked the obvious stuff 10 seconds after I landed it when the change in pitch was noticed. It's not in the radio set-up. It's on a Hitec Aurora 9 that I fly everything from my 35% Extra 330 to my smallest heli.

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Old 08-01-2013, 05:09 AM
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Default RE: Viper500 Tips Before I maiden it ?

I race Club 40 with a TT 40 Pro and from years of running them I can tell you that that is not the right prop for that engine. Head over to the Club 40 forum for more info. There is way more speed to be had with that Airframe and Engine combo.
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Old 08-01-2013, 05:21 AM
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Quote:
ORIGINAL: iflyg450

I race Club 40 with a TT 40 Pro and from years of running them I can tell you that that is not the right prop for that engine. Head over to the Club 40 forum for more info. There is way more speed to be had with that Airframe and Engine combo.
As do I. I have 3 Skyraiders and 4 TT pro .40s. I have experimented with many combos. This combo with the TT on the pipe with a 8.8 x 9.0 creates the most thrust (measured on my pylon plane test stand) and turns 16,500 static. How much better can it get?
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Old 08-01-2013, 08:12 AM
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Default RE: Viper500 Tips Before I maiden it ?

My hats off to you sir. I might have to give that prop another chance.
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Old 08-01-2013, 10:03 AM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: iflyg450

My hats off to you sir. I might have to give that prop another chance.
Maybe my thinking is off, but I was under the impression if you can turn say a 6" pitch prop at 10,000 RPM and a 9" pitch prop at the same 10,000 RPM, the 9" pitch will be significantly faster. Obviously drag increases with speed and all that, but in the rawest sense, the larger the pitch, at the same RPM, should yield a faster speed.

But this is just a toy. I am not pylon racing it. Just hot rodding around the field for fun.

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Old 08-01-2013, 10:48 AM
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Default RE: Viper500 Tips Before I maiden it ?

The thrust calculators I've used don't consider the pitch...changing just the pitch doesn't change the static thrust readings.
Static thrust is based soley on diameter and rpm
If your 8.8x9 is producing 4.3 pounds at 16,000 rpm that same engine might be able to turn a 10x5 pretty easily at 16,000.
If so, then it would be producing around 7 pounds of static thrust.
Static thrust is what you want to know for setting up a hovering plane.
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Old 08-01-2013, 03:23 PM
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Default RE: Viper500 Tips Before I maiden it ?


Quote:
ORIGINAL: Giant_Scale_Gasser

Gonna maiden my new Viper500 this weekend. Everything set exactly to the book. TT Pro .40 on a tuned pipe turning a 8.8'' x 9.0'' APC at a tick under 16,000.

Anything I should know before the maiden? And speed tips (other than putting a Jett in it, which I will be waiting patiently on doing once it gets maidened and sorted out).

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Rip out the entire firewall now, while you still can...and replace it with a decent one, that's decently glued...
And tether the engine to the plane while you're still flying with the old firewall...
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Old 08-02-2013, 12:33 AM
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Default RE: Viper500 Tips Before I maiden it ?

Excellent tip Rudeboy. I had a wing fold on a hard turn over our pond. Fuse hit the water hard, bobbed back up and floated. Rowed out and picked up the fuse, no engine, no fuel tank and no throttle servo.
Might be a good idea for any plane at my club.
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Old 08-06-2013, 11:10 AM
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That is true but you need to match the right prop to the engine and airframe. If you come in to a forum asking for help then to take the advice given to you then do come and ask for help.

Again as three peopl have said that isnt the right prop for that engine and airframe. From what you stated in here it doesnt seem you dont know how to set up pipes for planes either. I am not trying to be mean to you but only help you.
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Old 08-10-2013, 08:26 PM
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Quote:
Originally Posted by airraptor View Post
That is true but you need to match the right prop to the engine and airframe. If you come in to a forum asking for help then to take the advice given to you then do come and ask for help.

Again as three peopl have said that isnt the right prop for that engine and airframe. From what you stated in here it doesnt seem you dont know how to set up pipes for planes either. I am not trying to be mean to you but only help you.

Really? Clearly ALL 3 are wrong. I tried the 9x6 last weekend. It was in the air for about 2 minutes before I landed and took that thing off and tossed it. I knew my static test stand numbers were decent. That 9x6 didn't work on my club40 pylon racers and they damn sure don't work on this thing! Especially with the conditions we have been experiencing here in FL lately. With a 9x6 the thing is an absolute pig. Slow and the motor never pulls down in the turns nor will it gain rpm on a down line. In fact, it sounds like a boat that is cavitating the prop or like a race car with a slipping clutch. It never grabs the air and goes. It just cavitates, or so it sounds.
Put the 8.8 x 9.0 and everyone at the field agrees and can see plainly, it's MUCH faster, unloads nicely and the motor sounds (and runs) much better.

Yeah you're right.... what do I know about tuned pipes. Pressure waves, Port Timing, Expansion chambers, scavenging, port velocities and the like.... My little .40 was already turning a 9.0 pitch prop at 16,000 static before all the naysayers about my prop selection. Now I have tweaked on the motor more, hand worked the prop, changed the carb (other carb was having issues) and now it turns just over 16,500 with the 8.8 x 9.0. I am interested to see how many of you have a TT Pro .40 that is STOCK and club40 legal (sans pipe), turning 16,500 with a 9.0" prop on the bench. Seems to me that is one stout little engine.

I came on here asking about anything I should know about the maiden on the airplane, not whether or not my prop selection suited anyone else. And honestly, any respectable engine guru will tell you that without knowing the specifics of someones set-up, their elevation, atmospheric conditions, fuel, engine details and a myriad of other factors, to just throw out a blanket "That's not the right prop" is simply absurd.

The 9x6 is a pig on my ship. 3 people suggested it, why doesn't it run right? Oh I remember, I put a pylon prop on and thought it was a pylon plane!

Oh and to the reply about static thrust... ah.... well your calculator is off. I have the digital scale on my test bench that says it absolutely does. I test all my pylon planes. Pitch absolutely changes the thrust because changing pitch changes the numbers on that scale. And you are right, thrust is great for hovering, but we are talking high speed plane right? I am not interested in thrust at 8000rpm. I used the prop that creates the most thrust at the rpm where the engine runs the best, which seems to be around 16,000 or so. What was that prop you ask...? The 8.8 x 9.0 APC. That is why it's on the airplane. Of the 60 props I have for a .40/.46 did you really think I just randomly pulled that one out, without any idea of what it was capable of (or what I was doing) and stuck it on the there and yelled "Pylon Prop.... Pylon Plane.... Yeeeeee Haaaaaa"?
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Old 08-11-2013, 11:25 AM
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You have little knowledge of going fast.

Your plane tied to a pull scale doesnt mean anything when in the air. all it means is you found the most thrust with ZERO airspeed.

Its a hobby and if you and your buddys say its fast then good, be happy with it.
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Old 08-12-2013, 05:45 PM
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I use to run on the Viper........ APC 9X8 on a Evolution 46 NT & muffler, 9X9 on a 45 YS & pipe, 9X6 on a OS 32 & pipe, 9X10 Webra 55 (round black head) & red Jett muffler. 10X10 OS 55 AX &muffler.
The header looks long in the O.P. so it will pull that pylon 8.8X9 @ 16.500. If your having fun, don't mess with it. There may be more speed with different SPORT props, but you will have to cut the header and experiment. Without doing a thing except tweaking the needle maybe I throw APC 9X8 on it.
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Old 08-23-2013, 02:20 PM
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Quote:
Originally Posted by airraptor View Post
You have little knowledge of going fast.
Really? How could you possibly say that without knowing a thing about my background or experience with 2 strokes?

Quote:
Originally Posted by airraptor View Post
Your plane tied to a pull scale doesnt mean anything when in the air. all it means is you found the most thrust with ZERO airspeed.
I wasn't looking for the most thrust. You seem to have that assumption as well as others. I was after the best thrust at or near 16,000rpm, where my little .40 seemed happiest. I can make bigger thrust numbers with other props, not at the RPM I was looking to turn it. And instead of taking 25 props to the field, it seemed to make sense to narrow down my selection with some data...

Quote:
Originally Posted by airraptor View Post
Its a hobby and if you and your buddys say its fast then good, be happy with it.
I am happy with all my planes, regardless of who thinks what. But as an reasonably accomplished pilot, I can tell you it was MUCH faster with the 8.8 x 9.0. But anytime you'd like to come by, share your knowledge and help me with it, I am willing to learn.
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