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Discussion Starter · #1 ·
Hi guys and gals


i have an idea wich stems back some 20 years when i started rc boat racing


The idea was to build a pulse jet rocket boat in 1/8 scale using the hull design of a miller american hydro . Well that idea went out the door until this past week when i started thinking about modifying my monster pirate and using a 3 stage onboard rocket system and going for a RC OFF ROAD SPEED RECORD


The idea is to set up two pods one either side of the truck and use a long burn rocket motor in three stages , the only glitch i can see thus far is getting the front of the truck to stay on the ground as i want to use the 3.5 cc motor to bring it up to speed and the ignite the rocket from a third channel on the radio , but as we all now with these trucks tend to pick up the front under power.


Anyway im going to leave this open for a discussion as i know 99% of you are going to thinks itscrazy the other 1% will understand because im a tasmanian


If you have any ideas or coments lets hear em





CHEERS Vanpyre aka Ian
 
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Discussion Starter · #2 ·
hmmm all i can say is fasssstttt!!!



tamsmanian, weeeee one more on the board

good luck anyhow..



Nismo
 

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someone in the US was crazy enuff to try thisa while back with a tmax and 6 D size rocket engines. here are his results::








Edited by: jiggen5354
 

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That looks like he put the rockets on the wrong way!!!

Wheelies are caused by lots of traction and lots of grunt.

You won't have this problem with rockets because the power isn't being put to the wheels. However, I imagine you will have to ensure that the rockets are parallel with the ground and any downforce from a wing would be beneficial for handling.

Just remember to do this somewhere that is very wide & open because once you fire the rockets, you can't shut them down until they run out of fuel.

If they provide too much power, you won't be able to steer, so how long will it be before you go out of radio range?

If you have a fail safe, set it so that it only brakes lightly, NOT to lock up the brakes - if you lock them up doing 60+kph with the rockets still burning, it might just rip the tyres off the rim before long.

You will definitely have to provide photos at the bare minimum. Getting hold of a digi video camera would be better!

Go nuts young man! Oggy.
 
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Discussion Starter · #7 ·
Hi guys


I am planning on doing this the right way when i say speed record as in full on speed record the two pods will be mounted on the side of the truck and i will acompany the truck in something fast enough to keep up so it will still be classifeid as rc not just a speed straight line car


Iam planning on have at least four video cameras working and timmingset up for the run as i would suspect im only going to get once chance per truck (thats a worry lol)


I am hoping will be able to enlist the help of Rosco with advice as he had a rocket powered go kart many years back before he went full on into the land speed record cars


the venue will be if i can get permission to do it at pierce air base here in West aus
 

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the very end of a d cell rocket does fire to other way but thats for popping the nose cone off the rocket so that it ejects the parachute. The problem here with 6 d cell rockets is it got too hot and caught on fire. having a tank full of nitro didn't exactly help put out the flames. i remember seeing the video of it somewhere online.
 

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wow.. tazmanians are crazy! LOL!

nah i like ur idea.. but u must be loaded


i can bearly keep my walet existing with just a plain savage and fuel costs!

lol





good luck with ur ambition!



cheers
 

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LOL I love the idea!


but are you going to run a rocket on both sides of the truck? hmm just think if one went off without the other....


Anyway if it was me I would aim the rocked slightly, maybe 2deg, down so that it keeps pressure on the front wheels. Also you want to get the firmest tyres - don't want them to elongate and lift your car, making it unstable.


Next would have to be making it as LOW as possible... LOW CG!





We tried to make soda-bulb rocket powered cars once - we almost always destroyed the cars first run...






Sweet idea but!
 

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Sounds like an interesting idea...
Could I make a suggestion?


How about forgetting using a truck or any other existing RC vehicle.


In fact, just junk the whole transmission, nitro engine & paraphenalia. You don't need it, its just dead weight and will probably cause more drag than you want.


Truck's tyres are hopeless for high speed. Seriously bad wind resistance & they will balloon which cause handling & ride height problems. It is not a good combination. Your best bet are foams; ultimate are alloy discs or drums with o-rings for tyres.


Rocket engines are pretty lousy at getting the car started from standstill... should take a tip from the Bonneville speedsters and have a 2nd vehicle that will push the rocket sled up to a suitable speed before you light the fuse.
 
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Discussion Starter · #12 ·
Hi guys


so far the idea is to have the 3.5cc motor push the truck up to speed around 80 to 90 kphthen use the third chanel to kick in the igniters at this stage the truck will have to be free wheeling


as to the truck being used i want to do this because its the hardest to use and its different the tyres wont be a prob filled with space invader and ground down to slicks


i do agree that it is going to have to be lowered to the maxx for the the ground force to kick in
 

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Vanpyre said:
so far the idea is to have the 3.5cc motor push the truck up to speed around 80 to 90 kphthen use the third chanel to kick in the igniters at this stage the truck will have to be free wheeling

no, bad idea. You'll have too much interference from the engine/clutch/transmission and it'll cause drag. Or the clutch could stay jammed on and your whole engine could end up overrev'd.


Even if you don't care about the engine/drivetrain, it means your high speed run is shot.





as to the truck being used i want to do this because its the hardest to use and its different the tyres wont be a prob filled with space invader and ground down to slicks

Forget filling your tyres with that sh*te. Its heavy and you'll never get your tyres balanced properly. (Had someone try that with touring car tyres, it turned out lumpier than Arnie!!) At low speeds a little imbalance doesn't matter, but if you're doing 100km/h it'll be very very important.


Have made slicks out of truck tyres myself... and the rubber's usually too hard to grip anything.





Have seen somewhere selling foam tyres on 1/8th buggy wheels... can't remember where now.
 

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1/8 foams are becoming more common. A few hobby shops around me have them at roughly $35 a pair.

I think Dei-Rossi (Campbelltown?) and Graham's Hobby Centre (St Marys) have them, but I might be wrong.

Oggy
 
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Discussion Starter · #15 ·
Rocket engines are pretty lousy at getting the car started from
standstill... should take a tip from the Bonneville speedsters and have
a 2nd vehicle that will push the rocket sled up to a suitable speed
before you light the fuse.


start at top of a big hill....if its a free rolling chassis, it will
pick up speed quick, maybe 2nd car to push along as zoomer said i
think..



Nismo
 

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Make a rig that holds it on a car then drive and use the rocket enignes to kick off when you get to top speed, Your gonna want alloy wheels and test it on flat hard compacted dirt (like the salt flats, where they do the real thing) they need to be thin less resistence, Your body needs to be slick and the rockets incased in alloy tubes shaped like a bullet (hollow) with no back on them for the rocket, get rid of the engine and trans mission, don't worry about brakes try making a chute rig or something, the Body will have to be custome made from fibreglass, not a rc body to flexable, This will cost ya a bit, but hey you might get into the guiness book of records
Might aswell custom build it all yourself, Make it low too.
 

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I don't imagine you'd be getting much steering ability when the rocket
is firing - so... Beyond a parrachute control - what are you going to
control remotely? Sounds like a rocket on wheels.
 
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