World's Fastest R/C Car, anyone?

[sanddrag]

Originally Posted by Scooter

If it were me, I'd take a .46 size engine off of one of my r/c airplanes

I think Thunder Tiger already makes a truck with a .70 helicopter engine. It goes fast, but not 112+ fast. Perhaps that's because it is a monster truck and geared for torque.

But an airplane engine is an interesting idea. They rev almost as high as the car engines but come in much larger displacements. It may be difficult adapting a clutch though.

[team222badbrad]

It may be difficult adapting a clutch though.

I would not bother even using a clutch! I would just make the thing direct drive. You would just have to implement some kind of remote kill switch (micro servo?)

If I were to build anything I would definitaly built a car with an engine not a motor!

Batteries are too heavy

[Maxzillian]

Oooooo, it's about darn time they decided to hold an official competition. I've personally been on the r/c scene for the last 5-6 years and have seen some pretty darn crazy creations. The following being two of my toys I've hand built... although the latter has been in the works for 4 years and still isn't done and the former has a little touch up work that needs to be finished such as strengthening the rear suspension and making battery mounts to hang the packs off the side of the chassis to keep the center of gravity down.
http://www.mtsquad.com/phpbb2/viewtopic.php?t=116
http://www.mtsquad.com/phpbb2/viewtopic.php?t=59

Anywho, I can't see a drill motor propelling one of those cars past 111. The brushless motor used in the record holding car would hit RPMs past 60,000 and still have power to spare. Hence why the latest craze on the r/c scene has been brushless motors. Compared to brushed motors they're over twice as powerful, more efficient, and more reliable. However, being a nitro guy myself I always ignore the new electric gadgets. Without a doubt, if you were to build a speed car, you'd need a on-road racing engine. Considering that the newest ones touch 3-4hp and still managed over 35k, I think they'd have enough power. The problem is taking that power and harnessing it in the most efficient of ways. So, and I almost hate saying this, the best drivetrain would be a belted drivetrain. With kevlar belts, it'd just barely be reliable enough to handle that much power. However, I personally think that a 2 wheel r/c vehicle would be the way to go. If you think about it, it's the most aerodynamic, stable (at high speeds), and efficient chassis design to use considering how little rolling resistane there would be. The only problem would be keeping the bike upright during the run while keeping it in a straight line. Perhaps a gyro to control a set of balance weights and some wires hanging off the side to act as training wheels? Either way, that's my two cents on the subject.

[Salik Syed]

forget piston engines
grab yourself a micro turbo prop engine...and connect it to the drive shaft.... search for wren micro turbines and you'll find it.

[RogerR]

they said that turbine power is allowed, and that made me wonder...what if you used a solid fuel rocket motor to spin a turbine? the only issue that i wonder about is rule #6

6. The vehicle must remain operable after its speed runs. Sacrificial motors or power systems that are inoperable after a run are not permitted.

would a spent rocket motor be considered a "sacrificial motor"?

the whole question is hypothetical, since i wouldn't know how to go about making this...i'm obviously out of my element.

[sanddrag]

Originally Posted by Maxzillian

Oooooo, it's about darn time they decided to hold an official competition. I've personally been on the r/c scene for the last 5-6 years and have seen some pretty darn crazy creations. The following being two of my toys I've hand built... although the latter has been in the works for 4 years and still isn't done and the former has a little touch up work that needs to be finished such as strengthening the rear suspension and making battery mounts to hang the packs off the side of the chassis to keep the center of gravity down.
http://www.mtsquad.com/phpbb2/viewtopic.php?t=116
http://www.mtsquad.com/phpbb2/viewtopic.php?t=59

That 6x6 is really awesome. Here's my coolest ride. http://team696.org/images/Mvc-018s.jpg I custom made the tube chassis. I did it when I was really young and I don't have it together anymore. The frame cracked in a few places over the years (I raced it you know) and I wanted to put it back into its original form. I also made a tube rockcrawler style chassis for my Clodbuster that is all together but I never got around to doing electronics and paint.

[Bcahn836]

Our school actually has a R/C car club, one of our teacher mentors is really into these cars. They race in the school parking lot and go off road with the T-Max then go back inside fix them and do it again. All of the members bring their own cars and just have fun. And most of them are on the robotics team which is cool.

[Maxzillian]

Sanddrag: Thanks. I love the sand rail. Personally I've wanted to build one for some time now but I never did get around to collecting the right parts for such a project. Now I can't tell from the picture so I'll guess. Is yours based off a rc10?

I wish our school had a r/c car club, but there really isn't enough inthusiasts in our school let alone the entire community to support such a thing. I personally know 3 people who have r/c cars, but none of them do it very often.

[sanddrag]

Originally Posted by Maxzillian

Sanddrag: Thanks. I love the sand rail. Personally I've wanted to build one for some time now but I never did get around to collecting the right parts for such a project. Now I can't tell from the picture so I'll guess. Is yours based off a rc10?

I'm glad you like it. I was going to put an interior of sort but I could not find properly scaled seats and didn't have the expertise to make them. It was based on Losi XXT.

As for this world's fastest challenge, I took a look around the Tower Hobbies website and here's what I came up with. The HPI Proceed looks like a very suitable platform for such a high speed car. I found that the Trinity Novarossi and Sirio racing engines have a claimed maximum RPM of an astonishing 44,000 and around 3 hp. With one of those engines and the optional gear set, the Proceed would have a theoretical top speed of around 134 mph. Now, in realityit would probably be considerably lower, more near the record of 111 mph. If there is some way to get another engine into a Proceed or make it use a 3 speed (like from the Kyosho Mad Force), it is possible to make a potentially wining car. Or maybe there's even a way to get two two speeds in series for four but I have a feeling for such a large space three would be sufficient. One disadvantage of the Proceed is that the engine is mounted transverselly, making it difficult to run a twin setup. Maybe something more like an 1/8 scal off road buggy chassis where the engine is inline and it would be easier to add a second one. Ofna has a car called the Ultra GTP that is like this but made for on road. I think Ofna even has a monster truck with two engines called the Twin Titan. Perhaps the engines could be swapped out and it modified for on-road racing?

The only bad thing about this contest is that RC cars cost so dang much and I haven't even heard of any sort of monetary prize. (Of corse having an RC car that goes over 100 mph would be a prize in itself)

[Maxzillian]

Honestly, the car shouldn't need a ton of power. The way you can get around that is by making a car with great aerodynamics and very little rolling resistance. So basically a car with narrow sedan tires or even foamies and a body that is as low as possible. However, if you do want to go ahead with the twin engine idea, I'd have to agree on using a 1/8 scale buggy. They have plenty of room for such a setup and I've seen it done several times before (the most memorable being Greg Vogal's Nitro USA-1 with twin engines and the ability to hit 67 mph).

[sanddrag]

Originally Posted by Maxzillian

(the most memorable being Greg Vogal's Nitro USA-1 with twin engines and the ability to hit 67 mph).

OMG I remember that! You read RCCA? That truck was so awesome. And he used those HG lexan shock bodies - it was like right when they came out. He was such a cool guy, does he still work for them?

Anyone remember Chris Chianelli? (sp?) He used to do the "Back Lot" He then went to work for DIY on his own RC TV show and now I guess he has his own line of Megatech products. He was awesome too. Too bad no more Back Lot though. Wow, I have so many old issues of RCCA. Probably like 100.

[Billfred]

Originally Posted by sanddrag

OMG I remember that! You read RCCA? That truck was so awesome. And he used those HG lexan shock bodies - it was like right when they came out. He was such a cool guy, does he still work for them?

Anyone remember Chris Chianelli? (sp?) He used to do the "Back Lot" He then went to work for DIY on his own RC TV show and now I guess he has his own line of Megatech products. He was awesome too. Too bad no more Back Lot though. Wow, I have so many old issues of RCCA. Probably like 100.

They still have backlot--just not his backlot.

(On the other hand, I guess you could compare the two to a 196X Pontiac GTO to a 2004 Pontiac GTO. But still...)

[team222badbrad]

Speaking of RC are any of you going to purchase the new Traxxas Revo when it comes out? I would but I just dont have $500 to spend.

http://www.traxxas.com/REVO/

[Billfred]

If Dave won't say it, I will--that's pimp.

Thing is, I'm an electric guy. Nitros just are too much of a headache for me, between the noise, the smell, the cleaning, the tuning, the fuel...yikes!

When they come out with an E-REVO, I'd probably be all over it. (Is it Revo or REVO?)