High speed G-maxx for ISC event, 100mph or bust

[Rivermaxx]

Just the front, rear really dont need it especially with the weight transfer.

[ZippyBasher]

Hey did you happen to Catch last nights episode of the "Mythbusters". It was about aerodynamics and creating less drag on a car with the addition of dimples. (IE. Like a Golfball) they were able to prove a 12% gain in gas mileage just by adding dimples across the entire car. They were using the science of a dimpled golfball will fly farther than a non-dimpeled using the same amount of thrust. (which is about 40%)

After reading through your thread last night I watched the epsidoe and thought that I would pass this info along. As I thought this might help you out with your goal. Wind is going to contribute in a huge way and every little bit would count when trying to break a new record. You should check it out. It may just give you that little bit extra of an edge over the comp. if you were to design the body correctly. Anyhow Good Luck.

[Rivermaxx]

Cool! I will see if its on hulu and watch it. Question is how am i going to dimple my body? Maybe a soldergun with a proper tip IDK.

[Bondonutz]

Great episode, 9% increase was amazing !

Heat gun and some sort of tool with the correct diameter ends.
Like this ?

[ZippyBasher]

http://dsc.discovery.com/videos/myth...-vs-clean-car/

Checkout Dirty Vs Clear Car High Speed 3

Good shot of the car

I was thinking Really thick Lexan ( Maybe .060 [or thicker] and a Countersink) Oh and a couple spare hours of time...

maybe you could try to make the underside of the chassis as flat as possible, creating less drag for air under the chassis. if you can speed-up the air flowing under the chassis, the difference with airspeed flowing over the body is minimized, resulting in less lift.

edit:
some additional info

Even with these limitations, the underbody is of major importance in the aerodynamic setup of the car. This is particularly true on the speedway circuits. In order to achieve an efficient setup, the front and rear wings are much smaller than on a road or street setup. The frontal area of the car is reduced in size so it can slice through the air, in an effort to reduce the drag coefficient. The front wings are not used for downforce on the speedway setup, but rather as a trimming device. The major downforce comes from the chassis and underbody design. The rear wings are also much different in appearance on the speedway setup. Instead of the standard wing or high downforce wing used on the road and street setup, the rear wing is almost horizontal with smaller endplates. The speedway rear wing is shaped to create less downforce and reduce drag. The optimum setup on the speedway is to create enough downforce on the cars so when they reach the corners they can run flat out. Drag reduction is more important than downforce on the speedway setup. The best setup would be an adjustable wing to reduce drag on the straights, but supply downforce in the corners. CART regulations, however, prohibit this type of setup for safety reasons.

found here: http://www.nas.nasa.gov/About/Educat...r/chassis.html

or, add a fan at the rear of the chassis: http://www.autoevolution.com/news/gr...17.html#image2

[PBO]

You can see Nic Case used that concept in quite an elaborate way





NASA is a great site, you can spend days in there!

[Rivermaxx]

Its fairly flat on the bottom other than the holes cut in the lower plate for the older battery cells the and the front has a slight kick up for adding more caster or camber (what ever its called) . see pic



I plan on using clear packing tape over the bottom holes too smooth them out.

[Rivermaxx]

I lengthened the chassis again this time with a mono block and I am using the long hardcore titanium skid for a wheel base of ~15 inches Hopfully to get more high speed stability. I was going to order a custom shaft from rc alloys but found out the savage xk rear shaft might work perfect. I started trimming the slipstream body up figuring out I should of left some of the plastic on thats supposed to be trimmed off. I figure out I screwed it up for the best setup for high speed. So it is going to be used for my g4 maxx now . So I started trimming the Jconcept body up to the best of my ability. I know some of you dont like the looks of it and I am kinda partial to the slipstream body also but this body looks like it would be better for the build after I mounted it. At least until I get another slipsteam I need to move forward. Understand I still need to trim the bottom up but I am planning on running a thin lexan sheet on the hole bottom of the truck to help with reducing drag on the bottom. I left the front of the body long also because I plan on running a front wing off a 16th scale ofna model that matches the rear wing almost perfect but alot smaller.

The front wing still needs to be mounted up.


Does it remind you of somthing ? Not exactly but you guys know what I'm trying to do .






Notice the esc is sticking out of the body because the body sits so low. It will still be protected by the roof and the wing. It couldnt of worked out better because it is perfect for keeping the esc the absolute coolest and easy access to the switch. right on top.

[JThiessen]

hmmmm....maybe you could have just left that horozontal piece of lexan on the front of the body instead of trimming it off - could have been your front splitter built in for free!

But in all honesty - I think to reduce drag, that front wing needs to extend to outside of the wheels so that it can open a pocket of air for the wheels to pass through.....I think......

[Rivermaxx]

There was no horizontal peice in the front of the body. I know what your thinking but I still have to trim the front of the body so the suspension will work. As it is now it is sitting on the ground holding the truck up. The wing is for more frontal down force and too help the air sweep up and over the hood of the body. I am hoping the front wing with vertical stabilizers help the truck track straight at high speed. Just an Idea and I am going to test it out. I am going to order another sliptream body and see if I can refine it.

[its me]

From goofing around with my jato I would say to try and find a wing that almost looks like a scoop..



this little wing came in handy when I pit a RB 523 in the jato, car became alot more stable at speeds with noticeable less tire wear.

[Rivermaxx]

Cool ! I am going to try it with and without. Not to get off subject but how did you like that rb 523? I have one for my sons predator t-maxx I heard its a ripping fast engine. I havent had a chance to try it out yet.

[PBO]

I think the simple shape of the MT body needs a simple shape for the front splitter. You may be able to make a wider splitter that is able to direct the air flow outside the wheels but I would have thought a wider version is ultimately more drag?

I can see a simpler shape even from that wing, if you ignore the body/nose & connect the existing radius...it does resemble the more rounded RC body

[its me]

Originally Posted by Rivermaxx

Cool ! I am going to try it with and without. Not to get off subject but how did you like that rb 523? I have one for my sons predator t-maxx I heard its a ripping fast engine. I havent had a chance to try it out yet.

it was absolute over kill but was fun as hell :) strong motor so pushing big gearing wasn't a problem.