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Old Aug 26, 2007, 08:48 PM
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Bvm Electra Jet @ Heart Of Ohio Jet Scramble

This has to be seen. The video just doesnt do it justice, although you will get a good idea

I have some video of the f-86 also. I will try to post it later in the week.

enjoy

http://www.rcgroups.com/forums/showthread.php?t=733814
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Old Aug 27, 2007, 12:38 AM
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I just did a doppler reading of the first down wind pass after takeoff. I got 166 mph and that was coming out of a dive. The video time was 31 to 35 seconds. That was the fastest pass where I could get a clean audio reading. Maybe someone else can take some doppler readings to verify this reading is correct.

Kirk
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Old Aug 27, 2007, 03:09 AM
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thought I put response in this one! but I got 171, and that was not a dive but a heck of a dive. Seems it cant be punched for that long either, but coulda been the pattern he was flying. The envelope is great though! just like a pattern job, thats what a sport jet should be. and really wasnt horrible but it didnt exactly leap off the ground. Maybe too much compromise in the tail pipe to get it to go fast?

Barry
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Old Aug 27, 2007, 04:56 AM
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The electra and 86 are fine aircraft. Quiet, well mannered, impressive vertcals, but they are not quick. If I could afford one, I would have one. However, I would not put an EVF in it as its too heavy, over priced, current draw is too high and I can catagorically state from facts I have at my disposal that watt for watt there is no performance or efficency advantage over any 120mm fan.

I was at SEFF. BV was on my left and the guy with the speed gun was on my right. The best that could be managed with a slight tail wind was 151mph in SL flight.

12s EVF version pulls the same watts evidently, if that's so, it won't be any quicker.

I venture to suggest that Kirks version won't be much faster, JR's Schriener F18 will only clip 154mph with the same power and its a smaller and lighter aircraft.

EVF Viper doppler I have puts that at 147mph. Chris True's 12s Starfire got 154mph with a shallow dive. Martins A4 Tam 12s Diess conversion is almost identical in performance to JR's F18, he flys at the same field as JR and agrees.
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Old Aug 27, 2007, 05:37 AM
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well F-18's are draggy too. and despite what one would think the verticals are not that impressive at all. I think the spark was better and its not even a full ds-94. just look at the slow take off you can see he no longer has static either in the quest for what little speed it has there. The TF should have a speed advantage over the Ds at under 5kw levels and the big A-4 is doing about 160 on just over 4kw(without the huge dive), so I would venture to guess kirks is gonna be a lot faster!

Barry
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Old Aug 27, 2007, 07:14 AM
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JR's BVM F16 was faster than his F18 with the same power system, unfortunatly it did not live long enough for a reading.

Electra vertcals are impressive because of the way it does them, not the speed, they are so quiet they seem they are doing it with so little effort.

I say again, with the same amount of watts at the same weight, there is no performance difference in the same model between the DS and TF. The EVF will be slower as it is heavier, weight equals drag. In a climb rate competition I reckon my 1527 12s Kee Cat with a thrust to weight of 1:7 will match or possibly beat any thing out there pulling the same watts.
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Old Aug 27, 2007, 07:40 AM
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LOL! You guys are funny.

The first 2/3's of the takeoff run is at about a 1/3 throttle to get it running straight, when he punches in full it comes off the ground a few plane lengths later. As far as "can't be punched long" well - punch it as often as you want if a 3 minute flight is OK with you . BV is flying 5.5 minute flights every flight, just normal throttle management there...

I feel like such a defender <g>. Tell you what, when I get mine done in a few weeks lets get together with 3 or 4 packs and have a multiple pack flyoff. First one to get in 20 minutes of flight time avg speed > 100 mph without melting the motor wins. You can do it as fast as you can change the packs between flights with the EVF.

When I had the same size motor (1521) in my Starfire I know it would have been molten slag about half way through the second flight without a 1/2 hour cool down between flights. With the bigger 1527 I have in it now I could probably make to 1/2 way though the 3rd flight before the smoke appeared.
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Old Aug 27, 2007, 07:58 AM
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the haters have arrived

This thing leaps off of the ground. As previously stated bob rolls out at about 1/3 throttle then punches it to full (transmitter restricted..full throttle, not absolute full ! ) There wasn't another jet at the meet that got off of the ground quicker.

Bobs first pass is in the "low throttle" transmitter position. As are most if not all passes. The only couple of times i saw him flip to the high throttle position during the only two flights i stood next to him were during verticals...which by the way are incredible. it gets so small its it hard to tell orientation.

This this was faster than many of the turbines in attendance.

enough for now.....
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Old Aug 27, 2007, 08:14 AM
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Hey Chris

You said it yourself, the EVF has a big heat sink, course it will stay cool. Cooler engines draw less current.

I will be the first to admit the EVF is supemely enginered and in the long term reliability stakes will be a winner over a carbon fan with the motor pushed hard..

Here we are talking performance, I have tested these units quite extensivly under the same conditions, tests which are all recorded, and what I state is true.

Facts and budget would say I would not buy an EVF for a performance advantage. Eqivilent to $1500 in the UK, Long term reliability because its got a big heat sink, maybe, the motor in there is a smooth case Neu like the 1527, perhaps with a different wined, they did not magically get better, they just run cooler.

The center body heat sink on the JHH E-Turbax works very well too, not as effective as the BVM.

Not just supposition and guess work from this end.....
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Old Aug 27, 2007, 08:40 AM
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Quote:
Originally Posted by kevin
the haters have arrived
If that remark is aimed at me, please re read what I have written an perhaps review what you have stated.

My statements are based on measurements made with equipment anybody can buy and can be repeated.

When I have permission, I will publish my results here as well as in the RCJI magazine.

I pride myself in being as impartial as I can be, I state the facts only.

No such thing as a free lunch with EDF physics, but saying that, the 12s unit that just arrived might provide a picnic.
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Old Aug 27, 2007, 08:49 AM
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Quote:
Originally Posted by k_sonn
I just did a doppler reading of the first down wind pass after takeoff. I got 166 mph and that was coming out of a dive. The video time was 31 to 35 seconds. That was the fastest pass where I could get a clean audio reading. Maybe someone else can take some doppler readings to verify this reading is correct.

Kirk
I concur.

Steve
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Old Aug 27, 2007, 09:08 AM
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I could care less about all the numbers...and blah blah blah
I think it is amazing! fast enough for me
looks like it flies awsome..so whats the big deal with the speed
everyone is so caught up about speed...
looks like a perfect jet to me

Ronnie
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Old Aug 27, 2007, 09:23 AM
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. . . because it's the fastest who get paid and it's the fastest who get laid.

Reese Bobby
Talledega Nights

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Old Aug 27, 2007, 09:43 AM
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What is this fascination with FAST??? (Notwithstanding the above).

I like to see my model in flight, rather than some amorphous blur streaking by -

(Of course, I have old eyes).

Maybe it's excess testosterone or something??

You could always get a slope glider and go 300 MPH.

Oh well, whatever gets you off!
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Old Aug 27, 2007, 09:47 AM
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duplicated
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Last edited by Whistling Watts; Aug 27, 2007 at 10:14 AM. Reason: dupicate
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