annie_himself

I heard that when you run your car w/ its body off it looks/goes faster and im doing a science fair project on that. Is there any articles on this, or personal experience? BTW, I have a XTM X-Cellerator.
Thanks, Antrell
a.k.a.:nitroboy01

Wide Open

with the body off there would be a lot more stuff in the slipstream of the car that interupts airflow. and in terms of aerodynamics that it a bad thing. a body, without adding much weight, would smooth out the airflow over the car and put some downforce on it if it has a spoiler. you would probably go faster with the body on, but it would be a minimal difference in the top speed. youd better have one accurate radar gun to pick up much difference, so get the most streamlined body you can find.

J_D

put it in a wind tunnel and have a look

d2cs2mdw

My Feedback: (-1)

Your are running some risk's without a body, if your air filter were to come off then you would more than likely suck in some garbage and trash your motor, also, I never run my rc'c without a body on them because it make's them hard to see for me at least out in the open, and I think it look's ridicoulus running one without a body, would your drive your 1:1 truck on the road with no cab?

J_D

I usually go for a bit of run without the body just to check everythings doing what its ment to, then whack on the body and give it a squirt.

But the main reason i put the shell on is for protection.

jakjr

My Feedback: (18)

On an electric TC, yes I think the body makes a large aerodynamical difference, there are no holes in the body, the front of the body is only a centimeter or so away from the ground, and the body is usually very tight fitting to the chassis.

On a nitro ST I wouldn't THINK there would be as much difference between running with/without the body (aerodynamics wise) as you have large holes cut in the front/back window for airflow, their is usually a large gap betwen the sides of the body and chassis allowing air to get in, and the front of the body is usually mounted up high enough that air will easilly go under it.

fastest_ntc3

I have a Nitro TC3. When I first got it about 2 years ago, I use to run it with the body off all the time, then it seemed a little slower when I put the body back on. I guess it depends on which body you have because some are more aerodynamic than others. Driving with the body off is not a good idea, it makes crashes 10 times more worst than crashes with the body on. I only drive with the body off when I am tuning something.

wave waker

maybe one thing that makes running without body faster because the engine can breath more freely, and have better cooling compare with a body on it.

other thing is visual misconception since it looks smaller without body, then it looks quicker compare the one with a body.

regarding aerodynamics wind tunnel is needed to be more accurrate.

E-snake

My Feedback: (2)

Running without a body would slow you down. Wide Open said it well. Also running without a body on a fast car is dangerous. While this won't happed with an ST, it can happen with a TC. When you are moving very fast without a body, you have no down force on the car. Air starts to move under the chassis and can lift the chassis up. I beleive the cushion of air is called ground effect. When the air lifts the car up, it can flip it and have a terrible wreck. RCCA showed what can happen when they tested a Schumacher and a CEN nitro TC without a body.

Ethan

Wide Open

exactly, air gets compressed under the car as it trys to all go under at once and it creates a high pressure area under the chassis. which is indeed called ground effect. (im also an airplane guy, so i know a thing or two about aerodynamics.) having the body on will help combat this by providing down force, plus it smoothes out the slip stream moving over the car.

E-snake

My Feedback: (2)

I'm an airplane and car guy. More car though. My planes cause me so much greif, and I can't seem to have more than 1 of my R/C's running at once -mowing season is over[&o].


Ethan

IBrakeForNobody

My Feedback: (16)

These RCs are so small that you wouldn't have to worry about aerodynamics much until you hit about 60MPH, which is when air resistance will play a huge factor.

cavfighter

after launching my T3 6 feet in the air without a body and watching it land on its lid I would have to say that I will never run a car without a body again. It gets really expensive. I firmly beleive that car would have been fine with a body on.

greasysnowball

it may appear to be going quicker with the body off because of all the somponents in it just wizzing by, but it really isnt. the body is pretty darn important. safty and speed. 2 things that ROCK!

Wide Open

i know that the difference wouldnt be astronomical, but thats just the way aerodynamics works. oh, and it doesnt matter until 60? if my 5 pound model airplane can still stay in the air at only 20, than i think it makes a larger difference than you think.

wave waker

+1, before the aerodynamic (in an rc car, not plane) will take effect lot of factor to consider, as stated above certain speed should be reach, the surface area of the car that cause a drag and not all car body is streamlined so it doesn't matter having a body will automatically has aerodynamic advantage, the engine power- since rc engines produces huge amount of power in proportion to the weight and size of the rc car the body aerodynamic is very minute to consider.

annie_himself

Well, on a nitro Fusion made by Megatech, is exactly 1mph faster w/o the body. but that was on a .21 1/10 on-road. And i have a .18 1/10 off-road. so.....yeah. Im maily doing it to get parts for my truck.....dont tell my parens, haha

michelob78

My NTC3 goes airborne without the body found that out the hard way, I was tuning it with the body off and tried a speed run, only to watch in horror as I just sunk a ton of money into it go cartwheeling down the street. It looked like a plane taking off, that was a bad day.

Wide Open

well it sounds like this thread is going both ways, so it would be interesting to find out what the actual numbers are for different cars, engines, etc.

E-snake

My Feedback: (2)

I don't understand the other side of the argument. I see no way that a car without a body could be faster than a car with a body that wasn't shaped like a brick. It makes no sense. Secondly Aerodynamics have an effect on anything moving-no matter how fast it's moving.

Also, you guys have seen examples in these posts of people wrecking their cars because they had no body to create the down force needed to keep the wheels on the ground.

Where's this 60mph figure coming from?


Ethan

annie_himself

Heres a link!: [link=http://img408.imageshack.us/my.php?image=id03408300015ia.jpg]Happy now!?[/link]

Wide Open

indeed i am, thats answered our question!

d2cs2mdw

My Feedback: (-1)

Mine to! lol

Tigger N. Bennie

I've had RCs go airborne with the body on as well as others I know--wing adjustment and the size of the wing is vital at times.

GeeReg

My Feedback: (1)

I would question the scientific nature of that linked test. A 1 mph difference can be caused by just about ANYTHING changing in between the runs (e.g. wind speed, temperature, mixture, whatever). Not to mention the accuracy of the equipment used. Is that the whole article? They could have been a little clearer about how the test was even done.