here are my thoughts on the aerodynamic Property's of my brick. (1980 cookie
cutter Camaro... not even the right body style of Camaro)
I am given X body size to work with Period.... I can't modify the basic body
but I can alter how that Body deals with the air flowing both over it and
under it.
We started looking at the car and had a given Sq ft of frontal area.... then
since my class ( Altered ) allows the full front air damn we opted to
control the air around the nose and limit any air from getting under the
nose or below the bumper With the air damn in place we covered the
Headlights absolutely Flush and smooth with NO barbs like rivets or the
leading edge of blank off plates. Then We lowered the car to the Maximum
extent possible to keep the air out from under the car..... Air flow under a
car is dirty ..... to many barbs...stops and eddies.... all of the body
panels are adjusted so that the air flows from the leading edge of the car
to the trailing edge of the car with no lips or bumps or bruises...... then
on the rear of the car we added the 10" spoiler with turned down ends which
extends the airflow off the back of the car as much as possible....
It's my thoughts that air flowing over and around the car wants to rejoin at
the rear and will actually lift the rear quarters of the car in that
attempt.... by adding the spoiler we simply made the air wait a few microns
of a second longer and hopefully will cause the car to be past that air
rejoining at the rear....
To measure downforce on the car I use the air pressures in the air ride....
it's not a linear measurement but it does give me a basic idea of how much
downforce the wind is having at any given speed.... I still need to figure
out how to capture that information....
Hmmm gots lots more thoughts just no more INK....
Keith
----- Original Message -----
From: Ed Van Scoy <edvs@idt.net>
To: <land-speed@autox.team.net>
Sent: Tuesday, December 14, 1999 6:30 PM
Subject: Aero
> Wow Mayf, looks like that analysis was done by a rocket scientist ;)
> Question (s)
> 18 sq ft frontal area on your Alpine? I know we beat this subject up
> last summer, but this number looks awful high. How did you arrive at it?
>
> As for rolling resistance, my book gives a tire friction coef. of .81
> for a radial tire on dry concrete: This drops to .1 on ice (naturally,
> deceasing with speed) Salt provides a challenge as it changes constantly
> within this range. If you had to ballpark a tire friction coef. for a
> slick 6" tire on salt, what would you guess?
> Ed
>
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