Here are some 'close' numbers you can use are CD ratio 0.35 for the GT and 0.37 for the Coupe. The frontal area is approx 18 sq feet (68" wide 45" high with a 85% adjustment factor).
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02:02 AM
88Fiero2M4 Member
Posts: 349 From: Stratton Colorado United States Registered: Jul 2003
I have Car Test and still use it, but right now I am using Desktop Dyno and Desktop Dragstrip. I want to get it down to where the numbers it produces match what the car is actualy doing. That will give me an accurate baseline from which to model changes and the effects. I like the iterator testing and being able to see the effect of changes in shift points, launch rpm, final drive ratio etc...
Gene
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06:37 PM
fiero77 Member
Posts: 389 From: Bloomington, Indiana Registered: Jan 2002
It is said that a Formula 1 car can drive upside down at 200 km/h as a result of its massive downforce. So how would you calculate the resulting wing coefficients for that?
As a start, let's get some figures for an F1-like car an get an approximation. An F1 car weighs about 690 kg. This amount to 690 * 9.81 (gravity) ~ 6770 N(ewton). As our F1 car has 2 wings, one in front and one in rear, that amounts to roughly 3380 N per side (given the CG is the center, while often in real life it is more to the back).
Now, 200 km/h = 200*1000/3600 = 55.56 m/s. Take a wing with span 1.2, cord 0.2, making a total area of 0.24 m^2, and an angle of 10 degrees, which is about 0.173 radians.
So, to get the downforce to reach the same level as gravity (so the car would float when hanging upside down), we can fill in:
So here we end up with a theoretical aerodynamic coefficient of 43.1 on each side (which may seem much too large, but note the angle was taken in).
So how much is drag? Generally, drag is lower than the downforce coefficient (i.e. the wings are better at generating downforce than they are generating drag, which is ofcourse by design
THE BODY
Note that the body as a whole can be seen as a subtle wing itself. The same formula applies, but this time it will be applied near the center of gravity of the body. Even without wings this aerodynamic fact is happening.
Coefficients of cars tend to vary between 0.2 for supersleek cars to 0.4 or even 0.5 for older or less aerodynamically efficient cars. Generally, even a sports car will do even 0.30. As a starting point, try 0.35.
What that means I don't know...but looks interesting to learn.
What he said!
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08:42 PM
gixxer Member
Posts: 451 From: Kent, Wa. USA Registered: Mar 2000
It is said that a Formula 1 car can drive upside down at 200 km/h as a result of its massive downforce. So how would you calculate the resulting wing coefficients for that?
As a start, let's get some figures for an F1-like car an get an approximation. An F1 car weighs about 690 kg. This amount to 690 * 9.81 (gravity) ~ 6770 N(ewton). As our F1 car has 2 wings, one in front and one in rear, that amounts to roughly 3380 N per side (given the CG is the center, while often in real life it is more to the back).
Now, 200 km/h = 200*1000/3600 = 55.56 m/s. Take a wing with span 1.2, cord 0.2, making a total area of 0.24 m^2, and an angle of 10 degrees, which is about 0.173 radians.
So, to get the downforce to reach the same level as gravity (so the car would float when hanging upside down), we can fill in:
So here we end up with a theoretical aerodynamic coefficient of 43.1 on each side (which may seem much too large, but note the angle was taken in).
So how much is drag? Generally, drag is lower than the downforce coefficient (i.e. the wings are better at generating downforce than they are generating drag, which is ofcourse by design
THE BODY
Note that the body as a whole can be seen as a subtle wing itself. The same formula applies, but this time it will be applied near the center of gravity of the body. Even without wings this aerodynamic fact is happening.
Coefficients of cars tend to vary between 0.2 for supersleek cars to 0.4 or even 0.5 for older or less aerodynamically efficient cars. Generally, even a sports car will do even 0.30. As a starting point, try 0.35.
What that means I don't know...but looks interesting to learn.
I want some of what you've injested. or..
[This message has been edited by gixxer (edited 07-18-2003).]
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10:28 PM
PFF
System Bot
gixxer Member
Posts: 451 From: Kent, Wa. USA Registered: Mar 2000
You know,...If we could find out the exact composition of the material used to construct the B2 and molded some new front facias, I'll bet you could sell a bunch!
You Don't Know the Power of the Darkside
