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Old 03-30-2011, 05:16 AM   #1
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Default wind resistance on nitro bodys

Ok just wondering on weather or not any testing has been done on hole placement on the front window of 1\10 th scale nitro cars as we have a machine at work that is a mini wind tunnel we use for tips on diamond cutters we make for underground drilling and i put three bodys through there paces to see how they would preform and just wont to know if my results were same.

Basicly how our machine works is a inferred camera captures video of air going over the item product or in this case the body, and the air changes coulor according to the resistance.

Now i found that the colours stayed in the coolest tempretures with the hole closer to the bottom of the window and with no side window cut out.

with a side window cut out it seemed to heat up de-noting that more resitance is present.

with a hole half on roof and half on window it seemed a lot of air would flow under the back end of the car but a meduim resitance.

this was all a average on 30 40 60 kmh test.

the guy operating the machine claims there is a program to defiy what it means in numbers as to resitance etc he will try and see if he can adapet it to what we did

i just though it was interesting whats are your thoughts
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Old 03-30-2011, 07:55 PM   #2
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THIS IS AN INTERESTING PROJECT !!!!!!!!!!!!!EVERYONE WONDERS ABOUT THE AERODYNAMICS OF ALL THE POPULAR BODIES AND THE HANDLING EFFECTS OF HOW THE AIR TRAVELS ACROSS THE BODIES KEEP US INFORMED ON YOUR TESTING.......WE WILL SEE IF THESE COMPANYS PRODUCING THESE BODIES ARE DOING THEIR HOMEWORK AND KEEPING THEIR WORD ON WHAT THEIR PRODUCTS CLAIM TO ACOMPLISH...........
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Old 03-31-2011, 12:35 AM   #3
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So I have heard a simple way to test the front/rear balance of bodies.

Take 2 weight scales, place one under the front part of the chassis and the other under the rear part. Put them on and set them to zerro. Place a fan in front of the car and switch it on and read the weight scales.

In this way you can read the downforce at the front and the rear, put them in a list and you can soort them out on steer, grip, stabillity and air resistance.
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Old 03-31-2011, 12:59 AM   #4
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problem is, that you need the fuel hole directly above the tank lid to fit a fuel gun in there.
Also, the side windows might give you an aerodynamic advantage, but I suppose it'll be difficult to use that advantage when your engine got fried due to the lack of cooling air.

IMHO, the most aerodynamic effect on sedan bodies is generated at the front splitter / nose and the rear wing.

The rest in between is basically a swiss cheese and I don't think you'l get any kind of predictable air flow there.

in my experience it really helps the rear wing if the rear window is cout out completely. Seems that the air that is going through the car will hit the wing cleaner this way.
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Old 03-31-2011, 05:51 PM   #5
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Still, would be a very interesting read on all the outcomes of cooling/fuel hole placement.
Using the fuel/cooling hole to maximum diameter, or within the rules, and including side cutouts, where could be the most optimum position for these that gives you the best cooling while giving you the least amount of resistance?
Good stuff! Im keeping up with this thread!!
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Old 03-31-2011, 11:10 PM   #6
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More drag =more downforce. Fuel access hole 1/2 window 1/2 roof creates more downforce the lower portion of windsheild is higher in downforce than upper. Also the rear bumper cut out creates a vacume to the under side of body sucking the car down wyle atmosphere pressure is pushing down the top side you'll notice almost all air entering body go strait down and sucked out the back just my observations from homemade wind tunnel and a string on a stick. Be waiting for more of your findings
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Old 04-01-2011, 01:08 AM   #7
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Quote:
Originally Posted by mxfred View Post
More drag =more downforce.
Surely not! Drag has nothing to do with downforce, it's just resitance against the froward movement.
Drag can also produce lift, which a lot of the air, that gets under our bodies does.

I once did a bit of oval racing with truck bodies.
I built an underbody that connected to the upper body almost all around the car, with a rear diffusor.
Keeping the air out from under the body, allowed me to run without the usually absolutely necessary rear spoiler.
The car had more downforce and less drag, which made it a good bit quicker on the straights.

In nitro racing, this is not possible, because we need the cooling air under the body.
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Old 04-01-2011, 03:54 AM   #8
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If you think about it, you need the downforce to keep the car to the ground without sacrificing too much speed, so in a sense downforce has drag built into itself.
To me, not speaking with proper knowledge or education behind this, its all drag and aerodynamics is just a way of manipulating it to have an advantage - which is downforce in this case.

Feel free to ignore this, but im just saying it from my POV.
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Old 04-13-2011, 12:11 PM   #9
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Default wind tunnel

I think the ideal would be the best possible relationship between the lowest drag, higher down force and the most efficient cooling possible ...

This optimal balance also varies with the car set / body / engine, and also for each track ...

It is quite difficult to do these experiments, even with a wind tunnel ... would have to experiment with different settings, analyze the results ... 'n this wold take some time ... each outcome would be ideal for every track condition ...

That's what the real teams in Formula 1 and other categories do, but it costs a fortune ...

But any trial is welcome!
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Old 04-13-2011, 03:48 PM   #10
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Quote:
Originally Posted by Q-B0R0 B0MBER View Post
THIS IS AN INTERESTING PROJECT !!!!!!!!!!!!!EVERYONE WONDERS ABOUT THE AERODYNAMICS OF ALL THE POPULAR BODIES AND THE HANDLING EFFECTS OF HOW THE AIR TRAVELS ACROSS THE BODIES KEEP US INFORMED ON YOUR TESTING.......WE WILL SEE IF THESE COMPANYS PRODUCING THESE BODIES ARE DOING THEIR HOMEWORK AND KEEPING THEIR WORD ON WHAT THEIR PRODUCTS CLAIM TO ACOMPLISH...........
You might need a new keyboard, caps lock key is stuck.

caps lock, autopilot for cool
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Old 04-15-2011, 08:51 AM   #11
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Quote:
Originally Posted by stefan View Post
Surely not! Drag has nothing to do with downforce, it's just resitance against the froward movement.
Drag can also produce lift, which a lot of the air, that gets under our bodies does.

I once did a bit of oval racing with truck bodies.
I built an underbody that connected to the upper body almost all around the car, with a rear diffusor.
Keeping the air out from under the body, allowed me to run without the usually absolutely necessary rear spoiler.
The car had more downforce and less drag, which made it a good bit quicker on the straights.

In nitro racing, this is not possible, because we need the cooling air under the body.
sounds to me you made your down force more efficient once you reach max dforce & least drag then more downforce=more drag. Look at fast cars at bonnaville torpido shapes then look at funny cars wedge shape. The longer frontal slope creats more down force & more drag an abrupt rear slope creats more vaccume more drag . now for les drag you want an air foil shape. You want the least amount of surface area punching through the air (less area for air to creat drag) and finish off with along gadual slope so atmosphirical pressure can sqease the slope pushing it forward like sqeasing the paper cup of a snow cone.CRAZY STUFF MAN.
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Old 04-15-2011, 09:36 AM   #12
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A few points:

1. Drag and downforce are two separate things. While it is true that increasing downforce usually increases drag, the opposite is NOT always true. As Stefan pointed out, any air that gets under the body will increase LIFT and drag.

2. I don't really care about drag. Give me a 10% increase in downforce with a 30% increase in drag and I will run quicker laps. Our top speeds and time spent at top speed are so small, even on big tracks, that drag doesn't matter all that much. Downforce does matter.

3. So in conclusion, any testing that only reads drag and NOT downforce numbers is pretty much useless to me.
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Old 04-16-2011, 03:55 AM   #13
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Almost all touring car bodies give no downforce as the shape is like a wing. You cant stop the wind getting underneath.

We run speed cars and almost all touring car bodies take off at around 65-75mph. We added side dams and this changed everything. The body makes loads of downforce and is good up to 120mph. I used a speed body with side dams on the track and its a lot faster in the corners
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