is this speed true ?
one guy sent me an email via youtube asking me to check up his top speed with a rustler after he watched one of my vid's at youtube. the video didn't show what was passing and the ( UNZEROED ) radar shows 103MPH .
i sent him asking for his setup. trying to do this at my place will fry my motor no question just want to here your opinions.
It looks like it could be going that fast, and I personally believe the vid, but there is def not enough proof in the vid to call that speed "official".
I've seen this video b4. I'm not sure he's actually going over a 100mph but he's definitely going really fast. Who knows this might be a legit video. Kind of crazy run high speeds like that at night on a city street. If he somebody on foot or even on a bicycle it would bad news for who ever got hit.
100 mph is around 150 ft/sec. The speed shown on the video could be around that figure. I agree with Jones that it becomes a dangerous projectile...
At night on a street? Crazy kids........:unsure:
There are rules when it comes to speed run vids... before it can be considered official. This is NOT official. But it does LOOK fast and could very well be doing 103... if the guy would try again and take just a little more time to document things it COULD become an official high speed run.
The problem again becomes, what is his setup. If its some crazy 1/8 powered rustler than its not really that impressive. If its a VXL powered rustler its VERY impressive.
Can you explain what the rules are, pav?
thats one of the better vids I've seen and it sure looks like it might be 100mph... wish he started with a seamless shot of the radar gun at 0, then I would be even more convinced.. as for where he was running it, looked like a decent place to try it.. the road was perfect, no traffic in the way and certainly no pedestrians in sight.. I would like to know the setup as well and definitely want to see the aerodynamics of the car and body..
[QUOTE=cenracer1;4756219]thats one of the better vids I've seen and it sure looks like it might be 100mph... wish he started with a seamless shot of the radar gun at 0, then I would be even more convinced.. as for where he was running it, looked like a decent place to try it.. the road was perfect, no traffic in the way and certainly no pedestrians in sight.. I would like to know the setup as well and definitely want to see the aerodynamics of the car and body..[/QUOTE]
+1 Everything you said, is exactly what I was gonna say! Continuous shot of the radar gun is a must. Never saw it at zero, so theoretically the 103 could be a car that was shot earlier... with all that said, I believe the video to be true. Just not well thought out to make it "legit". That "rustler" was moving! You could have told me it was a matchbox car... just a blur to me!
No question the car, whatever it is , is going very fast. Not showing the gun zeroed is one thing but the way the guy chases the car as it passes by him makes it rather questionable IMO.
[QUOTE=Petertje60;4756095]Can you explain what the rules are, pav?[/QUOTE]
I think that pav was refering to the basic rules of shooting speed videos which is that anyone should record one shot scene showing the car while passing infront of a zero radar screen or resetting a gps on the rc car and making the speed run in one scene.
Good question - it's fast but I doubt it
If some of the above mentioned "issues" were addressed it would be more credible but I have other reasons also...
1. Night time runs always look faster
2. As Dad mentioned - the radar cosine error from jumping around. Radars must be stationary
3. The setup is more 'stock' than anyone else has been able to achieve that speed range
4. The cells they're using aren't of the highest performance (powerful cells could make up some speed IMO)
5. I've followed this group of people making these claims & have never had one technical question answered
6. This video (from one of the group) shows a very poor understanding of RC techniques & principals. It makes silly claims about what's possible
So he goes to all this trouble to prove his speed but doesnt bother to set up the radar gun on a tripod and just do the run again... then we wouldnt have to "just think about it" we could "just look at it".
Heres the problem as I see it... a Rustler powered by a 2200kv castle motor and 6S lipo SHOULD go over 100mph... thats not that impressive to me. Id like to see the aero package and how he managed to keep the nose down but the video shows NO shots of the car NOT moving...
Anyway, as has been mentioned... the rules for a speed run are simple. If you use a radar gun it must be stationary, you must show it zeroed in the beginning of the shot, then stay on the GUN, not the car, until after the car passes and the max speed has registered... then in the same shot show the car so we know what it is and what the setup is.
If your using a GPS you must start the shot by showing the GPS being zeroed then, without cutting the shot show the complete pass and end with the max speed with the GPS still attached to the car... this way we know theres been no funny business. I cant imagine why anyone would WANT to lie... but rules are rules.
Thanks for the explanations. Rather logical ones.
Yes, those calculation always like making drug test for humans " in vitro ". it shows something but in reality it's not.
calculating the wind resistance, on surface traction differences will always will affect the overall results.
anyway, i sent the speed record claimer a new message questioning his setup.
it might be not a rustler from the beginning, i magnify a snap shot and it looks - to me - with a very big wing if i'm not wrong.
the arrows point to what i think it's a white wing just at the rear of what ever that rc car is.
i just went digging in about his uploaded vids, this man appears did something. i watched his video, he was hooking up a 1/8 CC's motor & well done setup to keep the nose down.
the video shows & explain everyting [B]BUT[/B] the language in that video so not acceptable in some parts of it so i will contact the mod's first to listen to their opinion before posting it.
I want to see how he set up the car as well... that combo should get the car to what he says, I don't believe the half throttle part, but talk is cheap... I went and looked at all the vids he had on youtube and the only one that shows a body is a blue one, not the red one as seen in the video.. Nothing conclusive as its just a stock body with the wing removed and any body will do for the video.. my problem is that body is a very limiting factor in speed runs.. Mine develops lift at 70, even with a wheelie bar all the way down it still takes off.. maybe someday we will see a complete unedited video with setup, run and speed shown all in a seamless shot..
sorry guys for not posting the video due to language restriction, but here's his setup with snapshots and i'll upload the video with sound edit later:
[B]CC's 2200 kv
2 X ( 11.1 lipo packs ) with optional ( single or Y connector ) wiring to run with 3 or 6 cell
Aluminum Integy Gear box
Gearing : ( Spur 36t of nitro Revo / Pinion 24t of HPI Savage aka "mod1" )
unknown amount of weight at the front to prevent wheelie.
Aluminum wheelie bar to protect the motor as he said.
Note: loop the diff. well is must.[/B]
o.k here's the setup video ( edited ) and also i found a video of a daylight speed run tests.
Not doubt they're fast, the sand/dirt trail confirms that. I still see issues. From Bushnell (the radar manufacturer);
"COSINE EFFECT ON TARGET VELOCITY
The Velocity will measure the relative speed of a target as it approaches
the Velocity. If the target is in a direct line (collision course) with the
Velocity the measured speed will be exact. As the angle of incidence
increases, if you move either right or left of this direct line, the accuracy
will decrease. The measured speed will decrease as you move off this
centerline. This phenomenon is called the Cosine Effect. It is called
this because the measured speed is directly related to the cosine of the
angle between the Velocity and the target’s direction of travel"
This really casts serious doubt over any claims the draven 'crew' make IMO. That & the distinct lack of understanding as demonstrated in silly claims like 135mph++ using BrianG's calculator. Can A Rustler go really fast...? sure they can. Can you tip toe down to your LHS & buy a swag of bits + lay down consistant 100mph runs - not likely
Here's a very solid speed run that shows the lengths some will go to for accuracy. Yes, yes, it's not a Rustler - it's just an example
WOW... that car is MOVING... haha.. I love that shot... that was amazing. Next he should mount the camera BEHIND the radar gun...
[QUOTE=Desert JATO;4757139]o.k here's the setup video ( edited ) and also i found a video of a daylight speed run tests.
Thats pretty nice!
4th run you could tell it was slowing down
[QUOTE=YumaJato;4757471]Thats pretty nice!
4th run you could tell it was slowing down[/QUOTE]
that's true & proofs that they were trying their best w/o editing.
PBO, if we look at a paused photos for both the touring rc car great speed run & the white rustler run, the Cos. effect in both test only differ a little, and that little only reflects a very tiny amount of error. even with triangle holder in the yellow touring car run, the car didn't pass just under the radar exactly. i would estimate the green gap for the yellow car with around 80cm to 1m, while about 150cm with the white rustler, so i guess it would only make a very small difference in the accuracy imo.
anyway, they both did a great job.
The Cosine effect will get a slower reading. When the car is on a distance from you that is 10 times as much as your distance from the track of the car (in the examples above that would be 15 and 8 meter), the error would be less than 0.5%.
I saw the specs someplace for the Cosine effect on a Bushnell radar gun and it was 1 mph at 12º angle. So while the Cosine effect is there it is pretty small.
[QUOTE=Dadx2mj;4757586]I saw the specs someplace for the Cosine effect on a Bushnell radar gun and it was 1 mph at 12º angle. So while the Cosine effect is there it is pretty small.[/QUOTE]
Weird that they express the error in mph. The error depends on the angle and the speed itself. In this case it is around 2%.
Cosine is only 1 of the radar errors I can see. Having your friend jumping down the road with the radar in his hand is another, there are other factors that throw out radar - this would be one. Let's just say they're getting 5mph +/- error...whatever, doesn't really matter, there are other problems aside from radar issues
Edit; I'm sure I could use a handheld radar & get high readings that look plausible on video but would increase the actual speed by 20-30mph
They don't understand what they're doing. They have clearly copied other setups & use props like BrianG's theoretic calculator to justify their claims...as in "theoretically it's right, therefore it must be"
Might be beginners luck, but I doubt it. Attempting to discuss their results to better understand what they were doing just brought the predictable defensive response that I was a 'hater' & all the usual stuff that somebody might use to discredit reasonable questions
As I have always maintained, 100mph has been done - but by people who have spent time & money getting it right - I doubt this group have stumbled upon a magic formula that others have missed
I agree with you PBO, after listening to and watching the video on his You Tube channel where he shows and explains his set up I was left with the feeling he really does not understand what he is doing and IF he did legitimately break the 100 mph barrier it was more luck than knowledge or experience.
It's not luck i did 6 to 7 speed run's at 100+mph befor i made a video about it. and my car was going up hill.
haha..draven i knew it was only a matter of time before you yourself got involved in this conversation....
Old thread but sure had fun reading it. lol