sydclement

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Good news fron South Jersey;
My Whiplash made it to 205 MPH today. These were down wind
with the radar gun in a stand and switched to transmitt locked
on, and top screen max speed recording.
The specs are as follows:
FUEL, Magnum YS NZ/DZ-20/20.
Plug, YS 4 stroke.
Prop, APC 9-8. I'm still waiting for my 8.8-9.75's
Wind, 10 gusting to 20 MPH.
Time, 2 PM EST 11-24-02.
Humidity, 50%, Bar pressure 30.08, Temp. 52 degrees.
On ground RPM, 17,900.
Radar gun, STALKER Split Screen.
Still waiting for my APC 8.8-9.75 props and the
I4C in the air tack. Then maybe I can get an average of 205 MPH.
I wish to thank the SOUTH JERSEY SKYDEVILS R/C CLUB for
giving up some of their flying time and giving me assistance
with these radar runs..
Syd Clement...

sydclement

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I new we could it Ric, Boxosticks.

kamlooper

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Thats insane!!!!

jlong34016

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That looks like a jett fire 50. Right? To get 205 mph you need at least 27,000 rpm with only 8 inch pitch. Did it sound like it unloaded that much? I have made it to 175 mph with a nelson qm40 but thats turning over 23000 to start with. Did it look like it was going that fast? Once i have used the radar gun for a while i can tell how fast a given plane is going. I occasionally get reading over 200 but know it not right. I dont know if its picking up prop signal component or what. The inflight rpm gauge should give valuable info.
I have four engines for my spiderman whiplash but dont know which to go with. Jett fire 50, jett fire 60, nelson fai,nelson qm40.
Guess i need to try them all and find out.

BTW do you know the weight of your plane?

Thanks for the info.

sydclement

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Hi Kamlooper.
The fun is getting it all together to make it go that fast..

Syd

sydclement

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Hi jlong;
I said 10 to 20 MPH down wind helping.
It weighs 4 pounds 7 ounces empty with an 8 oz tank.
I flew a FOXFIRE with a Webra 50 and no wheels just
before the Whiplash at 140 MPH and it was slow compaired
to the Whip.

Syd

BruceDana

MPH or KPH? What was that Gun set on? Like Jlong noticed, that engine would have be spinning 10,000 more RPM in air than on the ground (you tacked 17,900 on the ground).

Incidently, did anyone record an upwind speed, or was this feat repeated more than once?

I hate to be the skeptic, but without a controlled test it is hard to believe. Case in point - Once my GPS displayed I was going over 220 MPH in a full scale C-205 (with no tailwind). Not likely, as I probably got multipath interference to the antenna laying on the dash (signal bouncing off the prop or cowl).

You usually don't break the laws of physics

Anyway, If this plane did repeat at 185 MPH airspeed then I be a believer.

sydclement

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Hang on Bruce, I'll get there weather permitting.

Syd

kamlooper

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I spse I better finish my DD up and see what speed is all about. I have an MVVS 40 se which should good enough for a beginner speedster I hope.

FlooredCOBRA

sydclement man I belive you. Thumbs up for the 200+ flight!

I cant seem to rely on the rpms with prop selection for the top speed theory. there are so many other variables out there to consider. Aerodynamics, tail wind speed when in dive. I don't think just because it tacs on their ground at a certain rpm that it will not go any faster than that.


For example: I also fly Buckeye powered parachutes and the posted top speed was 30 mph. With a GPS and flying right over a truck it flew 45 with tail wind. Even though the prop and rpm may of been 30 mph top speed on paper. This was while running 6500 rpm. So rpm and props may have an idea on speed but you cant just rely on that to achieve a high speed.


http://www.buckeyepoweredparachutes.com/582dm.htm

jlong34016

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Nobody ever said it wont go faster than ground tach would indicate. The ground speed tach would be 135 mph. The engine will unload in the air. It will pick up 5,000 rpm on a good day maybe(depends on alot of variables). I think the point is that the tail wind was probably much greater than 10-20 and claiming 200 mph with a big tailwind makes for good reading but does little to help people trying to get to 200 mph. So we have another 170 mph pass...maybe. Not bad but only 25 mph over a stock os 46 fx. Those extra 30 mph are very hard to come by.

FlooredCOBRA

I think for someone to get an actual top speed would be very hard to do. Even a fart of a wind will jump the speed up. It would be very hard due to you have to turn back around and head back the other way before you loose site of it.


I am not sure if this could be done but I think there may be a good way to determine the top speed. It would have to have an actual real time measuring device with a clock or something to time it with. Then fly WOT in a straight level flight and just keep going until the numbers don't go up anymore. Only thing is it would go out of range.

Oh well, to bad we cant just get inside of these things and find out ourselves.

jlong34016

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I get five minute flights. I can fly right to left and left to right on the same tank. If i get 200 one way and 140 the other that tells me 30 mph wind and i am going 170.

FlooredCOBRA

thats doing better than me. I am getting 2 minute flights. I gained by not having it popping out of my DD but lost alot of flight time.

May go with 2 four oz tanks in series. 2 minute flights are not cutting it. Guess I am going to loose a bit of aerodynamics now.

"Just Canopies"

1 question. Are these speed runs being done at a flat and level run or you coming out of a dive?

daven

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I have used a radar gun identical to the one used, and know it to be pretty accurate.

I would suggest taking 5 passes downwind, and 5 passes upwind, and average out the results.

Now if your just trying to get the fastest reading possible, do exactly what you did. Take it way out, nice and high and dive back downwind towards the gun. Just hope your not the poor schmuck out there holding the gun.

sydclement

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Hi Mort:
I make a big diving turn, then level off low about 80 yards
before I get to the radar gun.
I'll try some split S's when I'm sure everything will stay together.
I have my radar gun on a stand in the center line of the runway
and gun is setup locked on transmitt and remember the fastest
speed. That way no one gets hit.

Syd

Glorfindel

If you got 200mph with that setup on that day, mine should go 230mph then

Wiplahs + Jett Q500 + 8.8 x 8.9 over 19300 rpm

sydclement

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Glorfindel:
You get a day when it's 50 degrees F., 50% humidity,
some dam good 20/20 fuel, a good plug, and a 10/20 down
wind you might get that 230 MPH.

Right now I'm working on average above 200 on the straight
and level. Just got my 8.8-9.75 props and the Whiplash is waiting for the right day..

Syd

jlong34016

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thats quite a bit more prop load than the 9x8. probably going to have to shave that prop down to get it on the pipe. Got a 9x10 for the jett fire 60. waiting for better weather to fly it.

BAGOSTIX

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I can tell you without a doubt, if someone had a powerplant capable of powering the whiplash to 300 MPH, the airframe would certainly accommodate that speed easily..
As I said before, we have done over 200 MPH unofficially with the Jett 50 BSE on almost every flight.
I can believe without any doubt that Syd and others broke 200.

Remember, its what the whiplash was designed to do...

Maybe one day we'll put the whiplash up against a turbine powered jet!! :stupid:

jlong34016

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is that rear or side exhaust? pipe or tuned muffler? what prop? what ground rpms? total weight? carb or venturi?

MMallory

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Syd,

Where do you fly? I would love to come and see this for myself. I'll bring along my Dust, a Magnum & an F1 racer for comparison.


Mark M.

Central NJ

sydclement

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Mark;
I have been doing the speed runs at the Vineland/Downstown
airport located on Rt US-40. Thats the route that goes between
Del Mem Bridge and Atlantic City The airport is located near
Landisville N.J.
E- mail me when your ready.

Syd

MMallory

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Syd,

I will contact you if the weather gets a little better. Otherwise, I will in the spring (it's too cold for a long drive this time of year). Keep up the speed race... isn't this fun?

Mark M.