BiggerDanno

If'n youre not gonna fly that LR-1, what ya gonna dew with eet?

Oh, getting old beats the alternative...

freakingfast

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Nah.....too warm and fuzzy.....as we stand looking at the ground, kicking an affixed rock....... LOL.

freakingfast

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Time to say bye bye to it.

combatpigg

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Sorry guys, but I've listened to a lot of speed passes over the years and what I come up with is about 170 mph down wind and about 140 mph up wind.
The up wind passes the engine bogs down to about static rpm and heading down wind it spools up to about 25500.

It is not feasible for a .35 to be able to turn a 8x7 well enough to do 190 mph.

I looked at the laps from 1:29 up to 3:20 and the down wind passes were pretty consistent. The upwind passes ranged from 123 mph to 147 which tells me that the wind was variable.
The truth is this... on a calm day this is a 155 to 160 mph set up measured over a distance of 600 feet.
A far cry from 190 mph.

airraptor

My Feedback: (66)

sorry to the OP about this going away from your original post.

faceman

No biggie raptor I extracted what I need from the conversation. Thanks again have 2 of those apc props coming. Just curious how do you land the plane with no gear under it? Do you get it close and shut the motor down then glide in on grass?

combatpigg

My Feedback: (3)

Belly landings on grass with a light plane are usually no problem unless you hit a mole hill or a cow paddy. Then you will have a mess to clean up.
Belly landing will increase your budget for props though. The short, stubby speed props are a little bit forgiving..but not by very much.
I normally let the engine run dry then glide around just enough to get lined up facing into the wind before landing. If you get the sense that the tank is almost dry, then climb the plane to give yourself the most options for where to land.

airraptor

My Feedback: (66)

as far as the props go on landings for planes with no gear just line the prop up so that when its gliding it will stop even with the wing. this will keep it out of the dirt. works everytime. the only planes i will use with no gear are the 15 size and smaller. That Lr1 had wire skid on it. It you want to know more let me know in a PM and i will give you lots of hints and how to set some stuff up. some secrets I may not want some to read .

I will start building my kobra soon also. i am thinking doing eflight 15-25 size retracts in a tail dragger config. I will be looking for 120 or so with mine on a magnum 25 or 135-140 with a OS small block engine turning a 8x9 at 18,500.

faceman

raptor I would be very interested to see that Kobra built. after reading this post I was looking at mine and wondering how to put retracts in it. Then it hit me too tail dragger!! Hmmm. Is it possible to get anything like the older pattern planes to go as fast as the ones you guys fly? I like the kobra but I hate to say itat (41) I think I need something bigger in the sky just so I can see it. I notice a huge difference from when I flew at age 13 compared to now. Almost lost the kobra this weekend in clouds, and mine is done up like the patriot so it has plenty of color on it. LOL

airraptor

My Feedback: (66)

yes you can it is a simple thing to do also.

Two great engines are the OS 95 AX and the 120AX. now some of those you will have to be creative on the engine mount. The OS 120 is a very very light engine. In fact its as light as some of the older 60 engines out there like the rossi and OPS.

If i was to do an older patter plane for the BPA if allowed i would use the 120 with a 90 size jett muffler and a 12x14 APC prop at around 11,000 on the ground. It would really unload much in the air maybe 2-300 or so. This would be good for 140-145 or so in one of these.

I have also done a Great Planes 46 size revolver with the 120AX and the 120 Jett muffler with a 14.5x14.5 prop at 9,200. it did just over 145 on that set up. this was verified with GPS in the plane. I took the GPS out of my car and flew on a no to very little wind day. I would fly 3-4 down wind passes and for this run i would throttle back to just above idle to fly in the other direction to get good readings the throttle back up for the down wind. I would do the same for the upwind.

here is a video of the revolver with stock muffler and a 14x12 APC prop. this set up was good for right around 138 average

http://www.youtube.com/watch?v=_TRgyqgiPtQ

airraptor

My Feedback: (66)

I was in the garage working on a Dirty birdy 40. while was waiting for some glue to dry i pulled the kobra kit down. It is bigger than i thought. i dont think i could reach 140 with a 30-37 size small block. I might have to jump up to a 40-55 size engine to get in the 140 MPH range. 400 sq qith a large airfoil. I think i could get it to 4.25 lbs with a 55 AX. I think a 10x9 at 14,000 might get me there.

C_Roundy

I Agree.

-But- AirRaptor has freely pointed that niggling data accuracy stuff out too. those of us who are discerning, saw all that right from the start when he posted that video years ago....

Still, I haven't seen a faster LR-1.

AirRaptor"s doin' alright C.P., and he keeps gettin' better faster than his (sometimes know it all tone) would lead you to believe. he is one of the few VERY good ones, he has tremendous potential; And I care about nurturing that potential.

I am more proud than words can say, of you CombatPig, for comin' back to this thread and (hopefully) giving him a chance to calm himself:
and maybe even stop taking implied credit for accomplishments that are not his

Now, as for you AirRaptor, humble yourself before me, for I am the light, and the way..............................

Lownverted

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CP can you please explain why there would be RPM differences upwind vs. down wind?

combatpigg

My Feedback: (3)

The force of the wind and also the force of gravity [in a dive] take a load off the engine which allows it to rev up.
During a prolonged straight away pass after a dive you can hear aggressively propped planes gradually lose the boost that was provided by Mother Nature.

Lownverted

My Feedback: (4)

How does the force of the wind have anything to do with it? It's not like the plane would "see" more or less going up wind or down. I buy the longer or shorter dive, but the wind theory doesn't work.

airraptor

My Feedback: (66)

I will say the guy filming didnt know you can wavescope these. also the wind was blowing thru the mic. the passes were not = distance each time from the mic which is required to have a good reading. you also need to know the temp of the day and many other things totry to get a good reading.

Again these are just a tuning tool. I have another LR1 built. i need to order some parts for the Jett 35. once those come in i will put my telemetry in it. then once i record the speeds guys can wave scope it then i will post my speed recorded by the telemetry to see how far off they are.

faceman

Man I'm reading these posts and you guys are really into this speed thing. Wow thats awesome. Guys like you guys are what manufacturers should be looking at to produce the products you want. Should change this forum to "Air Dragsters" BTW curious again would any type of injection of more nitro or an inflight pitch tunable prop make any difference in speed?

iron eagel

Try to get the air temperature at flight time when you get your data, the temperature does make a bit of a difference for what waveoscope will give you for a readout like you said.
Combatpigg has gotten some fairly close readings for some of his planes using on board telemetry and waveoscope.
I think even the type of microphone used can cause some difference in the readings with waveoscope. Still it is a nice tool when you don't have radar on on board telemetry to get a good idea of what your performance is...
I think they spec the accuracy as plus/minus 15 kph for the program.

combatpigg

My Feedback: (3)

Flying down wind the engine doesn't have to work as hard to pull the plane. This allows a combo that is aggressively [over] propped to rev higher than it normally would. Both the wind and gravity have energy that gets fed through the prop.

Lownverted

My Feedback: (4)

Wrong. Nope. Not even close.

The plane sees the same airspeed regardless of the wind or direction. It is flying within a moving air mass which will change it's speed relative to you and the ground, but not to the plane it self. It sees the same relative wind no matter the direction.

Think of a boat going 20 kts in a stream that has a 5 kt. current. Measuring from the bank with a radar gun, the boat will be going 25kts downstream, and only 15 kts upstream. The boats speedometer will read 20 kts no matter the direction however.

This is the same thing the "down wind turn" guys don't understand.

I'm not debating whatsoever that you can dive a plane and get it to stage, or come up on the pipe, or unload to turn higher than normal rpm. Saying the wind has anything whatsoever to do with it is pure 100% bunk though.

airraptor

My Feedback: (66)

CP wrote

"Flying down wind the engine doesn't have to work as hard to pull the plane. This allows a combo that is aggressively [over] propped to rev higher than it normally would. Both the wind and gravity have energy that gets fed through the prop."



PIG you are dead wrong here. the engine works the same upwind as it does down wind. the plane flys the same speed down wind as it flys upwind. the thing confuse 90% of people flying R/C planes is they think the plane is flying faster down wind. You see the plane flying faster because of the wind speed. all the plane is doing is flying the same airspeed but it going with the wind. the planes airspeed plus the wind speed add or subtract to the GROUND speed.


AGAIN this flight was not set up for a speed reading off of a microphone lol the distance from the microphone isnt the same everytime, the wind noise thru the microphone add in variables to the mix.

Lownverted

My Feedback: (4)

PIG you are dead wrong here. the engine works the same upwind as it does down wind. the plane flys the same speed down wind as it flys upwind. the thing confuse 90% of people flying R/C planes is they think the plane is flying faster down wind. You see the plane flying faster because of the wind speed. all the plane is doing is flying the same airspeed but it going with the wind. the planes airspeed plus the wind speed add or subtract to the GROUND speed.


AGAIN this flight was not set up for a speed reading off of a microphone lol the distance from the microphone isnt the same everytime, the wind noise thru the microphone add in variables to the mix.


[/quote]

Get outta my brain!

iron eagel

It is a very easy wrong assumption for the observers from the ground to make.
It's the old ground speed vs airspeed thing. It is really driven home when your flying full scale.
A flying trip up to north western Maine in a cub can take forever, with a 30 mph head wind, in a plane that does 80 or so tops because your ground speed (at cruise) is only 40 if you lucky.

combatpigg

My Feedback: (3)

Get outta my brain!
[/quote]

Wind noise through the mic adds fuzz to the lines on the graph, but that is all that it does. It can make the pass hard to read.

If you can't understand how / why engines behave unloaded VS fully loaded, just enjoy the sport as best as you can and don't let any of those mechanical details get into your brain.

Lownverted

My Feedback: (4)

CP,

I understand obviously quite clearly how and why engines unload. I would suggest that it is in fact you who doesn't understand how wind effects (or does not in this case) a flying aircraft. If you want to bury your head in the sand, dig in your heels and be "right" no matter what, then so be it, nobody can help you. Just don't be surprised when other folks take exception to what you have to say.

For other folks who are reading this I think it's important to not present myth & plain untruths as fact. Should you choose to educate yourself, there is tons of information out there. I would suggest starting with a private pilots handbook.