Downforce
Thread Starter
Pro
Joined: Jan 2001
Posts: 526
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From: Sierra Madre
Downforce
Hey Guys;
I have done a search but couldn't find what I was looking for.
Does anyone know how much downforce our cars create at certain speed X? I was reading an article on lotus and was amazed how much it was producing.
Sorry if I am using the incorrect terminology.....
I did find one post that talked about the rake of the car and the safety of going a certain speed though; had a pretty good link too.
Anyway, just curious
Thanks in advance,
Glenn
I have done a search but couldn't find what I was looking for.
Does anyone know how much downforce our cars create at certain speed X? I was reading an article on lotus and was amazed how much it was producing.
Sorry if I am using the incorrect terminology.....
I did find one post that talked about the rake of the car and the safety of going a certain speed though; had a pretty good link too.
Anyway, just curious
Thanks in advance,
Glenn
Thread Starter
Pro
Joined: Jan 2001
Posts: 526
Likes: 0
From: Sierra Madre
Here is the original thread that talked about the rake:
http://forums.corvetteforum.com/show...ight=downforce
This is the link that was also embedded inside the thread that takes you to a "Race Car Design - Aerodynamics" website.
Pretty good info.
http://www.gmecca.com/byorc/dtipsaerodynamics.html#FA
Le Mans Master
Joined: Apr 2005
Posts: 6,413
Likes: 9
From: The Old Dominion
If I were to guess, and it would only be a guess, but the car probably does not produce downforce. I would guess things like the chin skirt and rake merely reduce lift.
I'd find the body design and aero to be an interesting topic for Dave McLellan to talk about. Maybe one day he'll talk about it in one of his podcasts. I've also always wondered why they changed the side skirt design on the ZR-1.
I'd find the body design and aero to be an interesting topic for Dave McLellan to talk about. Maybe one day he'll talk about it in one of his podcasts. I've also always wondered why they changed the side skirt design on the ZR-1.
Drifting
Joined: Jun 2001
Posts: 1,704
Likes: 459
From: Mass Mass
Drag coefficients are easy to come by, but you don't see Lift coefficients released very often, from the manufacturers.
Maybe it’s a liability issue?
A few years back, I team taught an "Introduction to Engineering" summer school class, for high school kids, at a local college.
We got to play around with a small wind tunnel, learning about airfoils, drag, lift, etc.
I managed to have them take a bunch of 1/18 scale models, set the ride heights, cut open the radiators, tape up the windows holes ,etc., and test them for Lift and Drag.
One was a C4, similar to one of these models
I dug up the graph results, for the vette ....
BTW...
Some people don't believe much in the amount of lift cars can generate.
I was fascinated by this video of a Tornado going across a parking lot.
Watch the two sedans, parked nose to nose, lifted up towards each other.
They are lifted up, not blown sideways, like you would think.
Now that's aerodynamic lift.
A Force-5 Tornado has winds from 261 to 318 mph.
The Max, Force-6, Tornado has winds from 319 to 379 mph.
Assuming typical sedan dimensions and lift coef's (CLfront = .136, CLrear = .246), total lift would be about 2600 lbs at 300 mph, and 3500 lbs at 350 mph.
I thought that was pretty amazing to see
http://www.youtube.com/watch?v=dKmMuFL2Fhs
Maybe it’s a liability issue?
A few years back, I team taught an "Introduction to Engineering" summer school class, for high school kids, at a local college.
We got to play around with a small wind tunnel, learning about airfoils, drag, lift, etc.
I managed to have them take a bunch of 1/18 scale models, set the ride heights, cut open the radiators, tape up the windows holes ,etc., and test them for Lift and Drag.
One was a C4, similar to one of these models
I dug up the graph results, for the vette ....
BTW...
Some people don't believe much in the amount of lift cars can generate.
I was fascinated by this video of a Tornado going across a parking lot.
Watch the two sedans, parked nose to nose, lifted up towards each other.
They are lifted up, not blown sideways, like you would think.
Now that's aerodynamic lift.
A Force-5 Tornado has winds from 261 to 318 mph.
The Max, Force-6, Tornado has winds from 319 to 379 mph.
Assuming typical sedan dimensions and lift coef's (CLfront = .136, CLrear = .246), total lift would be about 2600 lbs at 300 mph, and 3500 lbs at 350 mph.
I thought that was pretty amazing to see
http://www.youtube.com/watch?v=dKmMuFL2Fhs
Team Owner
Joined: Mar 2001
Posts: 30,861
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
That's pretty 
Yes, our cars in stock form produce lift.
Think about it, round on the top, flat on the bottom, it's a wing.
Take a look at what happens to this Camaro racing @ Bonneville
This RX7 does a backflip!
All the additions you see to racecars like the C5R, C6R and to counteract it, and make downforce instead. But racecars don't have to deal with things like speed bumps
You can get some nice bodywork that helps out a lot, Greenwood's kits come to mine.
But it's not easy to engineer.
Yes, our cars in stock form produce lift.
Think about it, round on the top, flat on the bottom, it's a wing.
Take a look at what happens to this Camaro racing @ Bonneville
This RX7 does a backflip!
All the additions you see to racecars like the C5R, C6R and to counteract it, and make downforce instead. But racecars don't have to deal with things like speed bumps
You can get some nice bodywork that helps out a lot, Greenwood's kits come to mine.
But it's not easy to engineer.
Last edited by BrianCunningham; Oct 19, 2008 at 05:34 PM.
