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-   -   Human Powered Vehicles Built for Speed (https://www.rc-monster.com/forum/showthread.php?t=21488)

Metallover 06.09.2009 02:01 PM

Human Powered Vehicles Built for Speed
 
We need to start adopting some of this stuff for rc speed attempts...

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I was surprised about the part with the wheel openings being half the aerodynamic drag of the whole thing... I should note the boat tails on a bunch of those things.

And the speeds those guys are getting, wow. If they can move ~250 pounds to over 75mph, we have some work to do with what, 3-4 horsepower moving less then 10 pound machines? :whistle:

What's_nitro? 06.09.2009 06:35 PM

That's cool. Some day when I move to AZ (:lol: "some day") I'll have to go for that record. You're right about RC's, we should be hitting 200mph by now. I'll have to work on that too.

Thomas 06.09.2009 06:54 PM

Think about it, it that thing goes 82 mph with 0.5 hp... leave out the poor human and put a properly-sized brushless motor and RC gear in :)
It probably has less drag than a regular 1/8 vehicle.

BL_RV0 06.09.2009 07:04 PM

That's true. I'm sure we could brew something up....

brushlessboy16 06.09.2009 08:17 PM

Nic Case holds the rc speed record at 161mph.... Rumor has it that one of his cars has seen 190mph

BL_RV0 06.09.2009 08:19 PM

Where is this 161mph video? I've only seen the 134mph video.

Metallover 06.10.2009 12:00 AM

I think a lot of it is tires. The skinnier the tire, the less rolling resistance there is, but you also get less traction. With fatter tires, you'll get tons of traction but there'll be a lot of resistance and friction... Or maybe we just need more room and a slower acceleration?

jnev 06.10.2009 12:50 AM

Quote:

Originally Posted by BL_RV0 (Post 294332)
Where is this 161mph video? I've only seen the 134mph video.

http://www.youtube.com/watch?v=PLOGA...eature=related

BP-Revo 06.10.2009 12:59 AM

Well, with our 5" diameter tires (or 2" with touring cars) we achieve more contact patch by increasing width.

With bicycle tires which are at least 20" in diameter, they can still be very thin but can have quite a large contact patch due to the diameter.

But that is quite impressive, I must say.

_paralyzed_ 06.10.2009 02:32 PM

Quote:

Originally Posted by brushlessboy16 (Post 294331)
Nic Case holds the rc speed record at 161mph.... Rumor has it that one of his cars has seen 190mph

Does everybody remember that I bought a neu 1521 off Nic Case? I did, and it's gone 140mph. How fast has your 1521 gone?:intello:

shizzon 06.10.2009 02:48 PM

Quote:

Originally Posted by BP-Revo (Post 294428)
Well, with our 5" diameter tires (or 2" with touring cars) we achieve more contact patch by increasing width.

With bicycle tires which are at least 20" in diameter, they can still be very thin but can have quite a large contact patch due to the diameter.

But that is quite impressive, I must say.

contact patch for a road bike tire at 100-120 psi is about the size of a postage stamp if not smaller, but i wouldn't think that breaking traction would be a problem for these things the way they are geared.

with all the power our cars have and the relatively short distance to get to top speed traction is more important, and finding a balance between rolling resistance and traction will be key.

if there was near unlimited runway then super skinny tires and wheels would greatly increase the speed, as you could slowly apply throttle to prevent loosing traction.

BL_RV0 06.10.2009 05:21 PM

Quote:

Originally Posted by jnev (Post 294427)

Thanks josh.

BP-Revo 06.10.2009 05:37 PM

Quote:

Originally Posted by shizzon (Post 294549)
contact patch for a road bike tire at 100-120 psi is about the size of a postage stamp if not smaller, but i wouldn't think that breaking traction would be a problem for these things the way they are geared.

with all the power our cars have and the relatively short distance to get to top speed traction is more important, and finding a balance between rolling resistance and traction will be key.

if there was near unlimited runway then super skinny tires and wheels would greatly increase the speed, as you could slowly apply throttle to prevent loosing traction.

I'm not saying that he has a massive contact patch, only pointing out that even though the tire might be super skinny it may provide much more contact patch than someone might think due to the diameter.

I do agree that if we put touring car width (or even skinnier) tires on all our vehicles that it would greatly increase top speed, but the new WFRCC rules have tire requirements for MT's, so that class is still screwed (tires have a diameter and width requirement).

I wouldn't mind going to that exact same stretch of road as they did and maybe having a chase car follow the RC to keep it in range. 5 miles is plenty of space for any solid 500hp to get up to speed, be it a Viper, Porsche Turbo Carrera, Corvette Z06, M5/M6, etc.

BrianG 06.10.2009 05:37 PM

Quote:

Originally Posted by _paralyzed_ (Post 294542)
Does everybody remember that I bought a neu 1521 off Nic Case? I did, and it's gone 140mph. How fast has your 1521 gone?:intello:

Bah, that's easy to beat. Just carry the motor in your 1:1 car doing over 130mph and simply throw it out the window (forwards of course). :smile:

BP-Revo 06.10.2009 05:38 PM

Or just air mail the motor to a friend and have him air mail the motor back. Boom, your 1521 just went at least 500mph.


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