vasek

My Feedback: (4)

[quote]ORIGINAL: SpeedBoy


SpeedBoy, my bad... my memory failed me there because I remembered something in the other post somebody mentioning to try pushing your Patriot to the 200 mph mark.... and i thought to myself NO WAY HOSE!

Sorry about that.
V.

Razor-RCU

My Feedback: (50)

You guys "Dopplered" it? Oh... Well that is what I get for reading parts of posts here and there I would certainly not disagree with the folks on here who doppler stuff.

I apologize for being so cynical- But I would never prefer a YS-45 to a Jett-50 or 60LX. I have had several YS-45's and they are AWESOME engines but even with a full tuned pipe I never got Jett-50 numbers.

I guess all my planes these years are much faster than I had thought.

Strykaas

I always thought you were a nice cool guy (can't be any other way with Flyboy Dave as a good friend), that was your first disappointing post.

Razor-RCU

My Feedback: (50)

I am sometimes nice and rarely cool, but I appreciate the thought! LOL

SpeedBoy

Only few pics more

SpeedBoy

If your incidences and the way of your dives are correctly I guess too .

I wonder how many rpm do you have with 10x7apc in your jett 50 ??? yes I know you run with 9x9apc , but I remember in my other tread you said that you tested a 10x7 and with not good results , really do you dont have them , I suppose you had at least 16,500 if so , why less than 120 mph do you confirm that result with other means ???

Could be possible a video of your patriot ???

Razor-RCU

My Feedback: (50)

Unfortunately my Jett-50 basically destroyed itself in flight....

I checked my Excel spread-sheet and I have 9x8 numbers but no 10x7. I was probably referring to flying results with the 10x7 as opposed to tach. results---I ALWAYS used a 9x8 APC as a bench-mark. The 10x7 was noticeably slower than the 9x9 apc. Why would I run a 10x7 when looking for speed? LOL

Some day I will get a NEWER Patriot and Jett-60LX and some video.

James

SpeedBoy

Your jett 50 what ???????? [X(]

Why would you run a 10x7 when looking for speed ? well I suppose that each airplane has its preferences I tested a 9x10apc on mi rossi 53 and indeed I had more rpm than a 10x8apc but as strange as it may seem not more speed , even with 2 pitch more [] .Now I just order a 10x10 apc and I'll cut to 9x10 , the objetive of that is have more area of prop than factory 9x10 .If our friends Mike connors and HighPlans was agreed in increase of speed with that prop something good must happen when I proves it , I have not surrendered yet and and I have faith in it

Razor , I wish to see your video some day

toro_0397

hi... does any one know where to get a ys 45 two stroke? are they still avaliable? i have searched without results
thanks

SpeedBoy

Hey toro this is a link of a YS.45 almost new , at least that say his owner maybe can help you

http://cgi.ebay.com/Futaba-YS-45-FS-...QQcmdZViewItem

toro_0397

thanks for the help

z06kal

FYI guys if you dive it right you can super inflate the true speed of the airplane. You'd be surprised how much a lil gravity helps . If the airplane has some pretty decent wing loading and isn't too draggy you'd be surprised how fast you could go with no prop at all. Just a matter of starting out high enough to reach terminal velocity. For example I had a plane that was doing about 135mph level but would easily crack 170 out of a big dive. I also had a very slipery 2 meter sailplane that did 210mph from a 1500 foot dive straight at the gun. Keep in mind pro skydivers can break well over 200mph in a good straight vertical tuck. THat is why doing these monster dives at the gun is a pretty BS way to compare planes. When I clock a plane and look for a real speed rating I always do a couple of completely flat circuits in the pattern to let the plane get up to speed then take it out far enough on the speed pass to let the plane accelerate out of the turn and run it by the gun completely flat. THe whole time I try to avoid gaining or losing any altitude. I then do this a couple of times to get a few consistant readings (guns often throw out erroneous numbers that cant' be trusted which is why cops have to establish a tracking history when they site someone for speed). Then you know how fast the airplane really is. Those big power dives tell you nothing more than how draggy the airplane is compared to its weight. FYI if they were to replicate this test with the ultrasport I would surprised if it even broke 3 digits. I see similarly draggy planes running a lot more power to just get to 130mph true level flight.

z06kal

FYI guys if you dive it right you can super inflate the true speed of the airplane. You'd be surprised how much a lil gravity helps . If the airplane has some pretty decent wing loading and isn't too draggy you'd be surprised how fast you could go with no prop at all. Just a matter of starting out high enough to reach terminal velocity. For example I had a plane that was doing about 135mph level but would easily crack 170 out of a big dive. I also had a very slipery 2 meter sailplane that did 210mph from a 1500 foot dive straight at the gun. Keep in mind pro skydivers can break well over 200mph in a good straight vertical tuck. THat is why doing these monster dives at the gun is a pretty BS way to compare planes. When I clock a plane and look for a real speed rating I always do a couple of completely flat circuits in the pattern to let the plane get up to speed then take it out far enough on the speed pass to let the plane accelerate out of the turn and run it by the gun completely flat. THe whole time I try to avoid gaining or losing any altitude. I then do this a couple of times to get a few consistant readings (guns often throw out erroneous numbers that cant' be trusted which is why cops have to establish a tracking history when they site someone for speed). Then you know how fast the airplane really is. Those big power dives tell you nothing more than how draggy the airplane is compared to its weight. FYI if they were to replicate this test with the ultrasport I would surprised if it even broke 3 digits. I see similarly draggy planes running a lot more power to just get to 130mph true level flight.

bob27s

My Feedback: (19)

Razor's Jett-50 was what I refered to as "Franken-Jett"... was created from James original engine, and a bunch of parts I had laying around. I was sad to hear of its demise, but it ran fairly well at least for a little while.

Last I tried it, my SJ-50 turned the 10x7 prop pretty well..... up over 16,000 easily on the ground. This is an interesting prop actually.... for some reason many engines prefer the 10x7 to the 10x6. RPM drop is not all that much between the two, and it tends to be quicker in flight.

I seem to recall DaveN noted his preference for the 10x7 as well.

The 60LX engine will get up over 17,000 with the 10x7 after it has been broken and run a bit. Peak of 17,500 is not difficult to achieve. Key is you want to back it off about 600-700 rpm for flight, and it might "fall off" the muffler. That is ok, but it can confuse some people - you have to understand how that works. Thus, we usually do not recommend the 10x7 prop because it keeps the engine on edge of that minimum recommended rpm.... so setting the needle properly is a bit more "important" - (trust in the setting like we do for the Q-500 and QM engines).

SpeedBoy

You right [sm=thumbup.gif] , I have a patriot wich fly at 133mph level and 170 mph on a dive , well recently went 172 mph and I even look for more speed on that set-up

SpeedBoy

bob27s : a 10x7 is not recommended even to a 60LX ??? or you mean not recommended to SJ-50 size ???

bob27s

My Feedback: (19)

The 10x7 is ok on the SJ-50, and works great on the regular SJ-60L engine (both with the standard jett-stream muffler).

On the 60LX the APC 10x7 can work too, and it turns the crud out of it ---- but as I stated, its on the edge because of the port timing and the muffler tuning. Has to the be correct plane/engine/prop/pilot combination. Thus the caution and reservations - it is the biggest prop you would want to run, and only if the plane is quick enough to allow the engine to unload properly.

I have no idea what sort of flight speed is possible with the combination.

Instructions provided with a 60LX engine
And also the product flyer we used when we introduced the LX engine line... just as a reference

z06kal

By the way guys regarding cutting down props. From my experiance this really hurts effeciency as the airflow across the prop gets completely mangled by not having a smooth transition. THe reason why it was slower with the 9" prop vs a 10" prop was much less thrust to overcome the drag. Pitch speed is quite irrelevent if you don't have enough prop to provide the thrust you need to attain the pitch speed.

bob27s

My Feedback: (19)

Quite correct... matching the prop/airframe/engine is the important thing. You want a good balance of performance. The patriot is a big, relatively draggy airplane. Lots of surface area, pleanty of frontal area. It makes a big hole in the sky. Same goes for the ultra sport.

Clipping a prop down slightly to allow the engine to turn up properly may slightly hurt efficiency - but it depends on the prop blade design in question. More importantly, the increase in rpm (obtain proper rpm for a tuned system) far overcomes any loss (for example, cutting a 9" prop down to 8.75" - its in the fuzz as far as the prop is concerned). So reconfiguring the prop can increase performance in some cases.

If you were cutting a 11x10 down to a 9x10, yes, you have a very valid point--- at that point it becomes a different prop. And the resulting rework becomes more than just cutting diameter, you have to work on the planform and airfoil - its a hand made prop.

SpeedBoy

bob27s , tank you very much by you answer , you leave me the things very clear [sm=thumbs_up.gif]

And yes I will have to make a work by hand in following prop that I proves, I will work near 2 hours (maybe more) to obtain the result that I want in each prop , I like work with props . What I am looking for , is load similar to 10x8 but with more pitch to take advantage of the power of the engine.

I hope the 3mm of difference of wide betwen a 10" and 9" prop can mark the difference and can give enough thrust to overcome the drag that need the airplane , if that work maybe the number of speed can change to up . ( This is about cut from 10x10 to 9x10 )

buzzingb

My Feedback: (2)

Regardless of speed the Ultra Sport is a very practical and attractive airplane. It flies like a trainer and run fast enough for most with sport engines. I am flying the Ultra Sport Plus 40 (which is a different airplane, slower) with a Super tiger 90 and it flies great but not as fast as this airplane.

Strykaas

SpeedBoy, could you please post a picture of your modified props ? One "before" and one "after". [:-] I'm really curious to see what you can achieve with a two hours work .

SpeedBoy

Yes of course Strykaas

The most of the work is in the area of the airfoil , and also I will reduce 1 inch in length and I will try to leave the original form of tips , when I make the job I'll show you (assumes that the props arrive this Thursday )

SpeedBoy

Here are the pics Strykaas

1 pic : the black zone was cut off
2 pic : to save hand work I did use the bench grinder ( only in the beginning )
3 pic : I did use sandpaper ( 3 differents , this is the "hard" work )
4 pic : show the measurement from the leading edge factory/prop 10x10
5 pic : show the difference between both leading edges reworked/prop
6 pic : from left to right ..... first-factory prop 10x10 ..... then- reworked prop from 10x10 to 9x10 ...... and last-factory prop 9x10

I dont know if this prop will work better than the other ones maybe dont , but I like work with props anyway

And yes I know I know maybe the skeptical man will appear and will say...... I dont believe in that ...... or Sorry ........ or my super combo bla bla bla , "mucho ruido y pocas nueces" that he need is sprinkle a little pixie dust in his airplanes to achieve more than the last 20 years was able to reach . LOL

Strykaas

Thanks SpeedBoy !
This is rather impressive [X(] ! I wouldn't dare to cut my props like this, I would be afraid to make them weak... But you've certainly got the skills !! Hats off [sm=thumbup.gif]