MPH Challenge

[Snook Man]

A buddy and I were having a discussion about RC’s in general and the age old debate between Nitro and electric came up. Long story short, he challenged me to build a Nitro powered RC that can hit the 100 mph mark.
I know it will be a tough task but the wheels in my head are already spinning.
It will be nothing like a Tmaxx but I do intend to use the Maxx rear end and transmission (with some modifications).

I need to do a little research about length and width for stability before I begin to think about making the chassis but this is something like I have in mind.

There’s no limit on engine size or distance, just hit 100 mph verified with gps.
Probably a little in over my head but I couldn’t resist.

Wish me luck…

[rcdriver5]

Cool Snook, I couldn't even imagine a nitro hitting 100, but if anybody could, it'd be you. Can't wait to see what this ends up as. Good luck.

[TastesLikeChicken]

Cool Snook, I couldn't even imagine a nitro hitting 100, but if anybody could, it'd be you. Can't wait to see what this ends up as. Good luck.

It can be be done. I have a stock 1/10 scale stadium truck that will do 70mph, 80 with a clutch bell change.
It's a matter of power to weight ratio, gear ratios and areodynamics.
Cool project to say the least.

[nitro on fire]

it deffinately can be done.. my nitro rustler can hit 88 with a 3.3 and a spur/cb change

[Double G]

Another thread I will be subscribing too for updates!

[Snook Man]

it deffinately can be done.. my nitro rustler can hit 88 with a 3.3 and a spur/cb change

Good to know, I think a N Rustler is around 4 ½ lbs…

I mocked it up a little to get an idea of the weight.

With a 4Tec front end minus the diff, a heavy BB engine and mount, heavy rear tires small fuel tank and a couple servos it is 5lbs 4 oz.
The 4 Tec front arms are aluminum so I can shave a little weight there with the stock stuff and once I get some light weight rear wheels/tires that can handle that kind of speed that should shave off some more weight. I bolted two chassis together for mock up so a custom chassis should weigh a little less also.
I’m not even sure if I need rear shocks yet.
With a BB and my 3 speed I think I can at least get close if I can keep it on the ground and pointed in the right direction

[ToXiC MeRv]

is that the rear end from the T-Muggy??

[lubecakes]

That wing may need some mods, but good luck, we know you can do it.

[Snook Man]

is that the rear end from the T-Muggy??

Its the old rear I used to mock up the TMuggy

I'm sure the rear and front wing both will need a bunch of work. I can see the front wing coming loose at 80 and having a blowover all ready

[Jersey Jato]

What engine do u plan on using?

[Snook Man]

What engine do u plan on using?

Undecided as of now... A Big one most likely...

[ToXiC MeRv]

Bigger is better...

[nitro on fire]

[QUOTE=Snook Man;4953261]Good to know, I think a N Rustler is around 4 ½ lbs…

its 73 ounces but yea i believe thats 4.5 pds

[humayrayakongkinaon]

count me in. snook wish you luck and go kick some electric's @$$.

Another thread I will be subscribing too for updates!

[lilypadjumper]

if a tether car can get real close to that 200mph mark, i am sure that with snooks hamster running in that wheel day n nite, he will come up with a good way to get half that speed, with out the tether
a youtube video of a tether car
http://www.youtube.com/watch?v=555aeQlPprY

[Double G]

Come to think of it, didn't Over_revO get someplace close with his nitro Revo a while ago? Too bad he is no longer on the forum; I believe he left around the time of the big upgrade about a year ago.

[rcdriver5]

Those tether cars are crazy, I would hate to be the guy in the middle. If you fell you would be in huge pain.

[ToXiC MeRv]

Those tether cars are crazy, I would hate to be the guy in the middle. If you fell you would be in huge pain.

you would probably get your legs cut off

[Snook Man]

Come to think of it, didn't Over_revO get someplace close with his nitro Revo a while ago? Too bad he is no longer on the forum; I believe he left around the time of the big upgrade about a year ago.

Haven’t seen Over_Revo on the forums in quite a while. I will be looking at his threads for some pointers for sure though.

Theoretically if I can get an engine to turn close to 30K rpms under the load and against the resistance, 100mph would be possible.



I chose a 1:1 transmission ratio because 3rd gear in my 3 speed is 1:1
Battery voltage and motor were chose just to get an rpm of around 30K.
Rear tires may even be a little larger diameter than 6 inches.

The 3.59:1 Rollout is very tall; a stock Tmaxx is less than ½ of that the engine would need some massive grunt… I knew it wouldn’t be easy.

[08kgraves]

I may be able to somewhat help u out Snook. I'm about to graduate from one of the best high performance schools in the country!

[johnny rotten]

Looks like a fun project! And I wouldn't worry too much about cutting out every ounce of weight. Mass has very little correlation with maximum speed obtainable, other than perhaps the additional tire deflection and bearing friction seen with increased weight, both typically being non-issues in speed trials.

[johnny rotten]

Unless you're racing uphill, that is...

[lubecakes]

Gearing and rpm is easy.....wind resistance is what's hard to calculate.

[Snook Man]

Did a little more mockup today.

After a little research I extended the chassis even longer (22 inch WB). The balance between the width of the rear and the length of the wheel base should make a fairly stable platform.
I added the steering linkages and associated fuel tank setup out of a 4 Tec, cut a set of old chassis braces for a temporary transmission mount and determined how high the engine will need to be raised to mesh with the spur (3/4 inches). I didn’t really want to raise the engine but it is the simplest solution for the gear mesh and it will allow me access for a roto starter. The top of the engine head is 5&7/8th inches off the ground with ¾ inch chassis/ground clearance. I will just have to play with the throttle brake linkages a little to get that setup right.

With most everything except a battery, receiver, servos and a few braces to stiffen the chassis it weighs in at just less than 6lbs. With everything installed I should be able to keep it under 7lbs RTR depending on the lid I choose. Surprisingly it has a better turning radius than I thought it would. I’m sure I will need proportional steering to keep it in a straight line at high speeds.

If I can find a lid to fit the layout nice and snug it should be pretty aerodynamic.

[fantomaxx]

Make sure you use some good lag screws,to secure that engine to your 2x4!!!..looking good are you going to go ahead and use that chassis or cut your own?

[ToXiC MeRv]

gonna need prob a 1/5 scale body, and those are EXPENSIVE!

[Snook Man]

I will be making a 1 piece chassis to custom fit everything, just a simple design like an elongated triangle or diamond. That way I can use a wedge shape body which I will probably end up making somehow.

[lubecakes]

Are you gonna take it over any sweet jumps?

[Tev364]

how did you get a tmaxx tranny 3 speed? that boggles my mind more then the rest lol

[MaxxViper]

how did you get a tmaxx tranny 3 speed? that boggles my mind more then the rest lol

Snook Man made a 3 speed tranny awhile back, heres his thread, check it out, http://traxxas.com/forums/showthread...eed-conversion

[08kgraves]

looking good so far snook

[2010450x]

Man every time I get on here Snook has another sweet project. I would like to have just half of his mechanical genius and fabrication skills. Good luck with the project and I'll be sure to subscribe lol.

[2010450x]

I was doing a little research, and if you have ever heard of powermaster fuels(made by VP race fuel) they have a drag specific 40% nitro. Just a little more help in hitting that 100mph mark

[1979chevy.]

Looks great!
But please tell me your going to get new tires and rims haha.




God answers prayer,pray,believe,NEVER GIVE UP!!!

[morganko]

I have got mine to do over a 100mph a couple times, on the freeway. But that was while it was in the back of the pickup =)

[Snook Man]

please tell me your going to get new tires and rims haha.

Yea, I'm sure those tires/wheels would not stand a chance. Everything is just in the mockup stage. I have all winter to get it ready.
I think 1 of the more difficult tasks will be finding a place to test it out.

Who is good with wind drag coefficient???

This is about as aerodynamic as I can make unless I point the nose a little more.
Being it is a simple wedge design I don’t think I will need a rear wing which will help reduce weight and drag… The chassis will be cut to follow the lower body line and I will use velcro to secure the body to the chassis to keep as much air out as possible.





I needs me a wind tunnel

[Double G]

I needs me a wind tunnel

I see another build thread coming...

[revomatic27]

I have a 19 tooth clutchbell if that will help with the gearing any at all. may not work though it is a not for 1/8 scale it's for the maxx or revo. just a thought

[08kgraves]

your going to want to round the top corners more if you can snook, and yes round front and point more to. and remember this.....

a teer drop shape is the most arrowdynamic desighn possible. so make it slowly taper to a fine point in the back and it will reduce the drag.

[Snook Man]

I have a 19 tooth clutchbell if that will help with the gearing any at all. may not work though it is a not for 1/8 scale it's for the maxx or revo. just a thought

I have an 18T 1/8th scale Mod 1 bell. If I need a 19T and yours is the revo bell I may borrow it to test with.