So far I have managed to get sideways twice. It is funny that both times
were after I moved the radiator into a atank of water in the passenger
compartment. I looked at the polar momen of interia (PMOI) and what it
can and cannot do or help and here is what I have come up with. Long
wheel base cars or even producion cars, have a high polar moment of
inertia. Short wheel base cars have a lower polar moment. A high PMOI
means the vehicle is resistant to starting a skid or spin but conversely
harder to stop one when it gets going. A lower PMOI means that it is
easier to get a skid or spin started but far easier to recovery from.
So I have a short wheel base car, I reduced the PMOI by moving the
radiator and water to a tank in the middle of the car making it more
susceptable to a skid. But because the PMOI is smaller now, it means
that I can recover it quicker. All verified by the fact that in both
cases the skids never turned into full on spins but were caught and
corrected befoe the car actually went around There are quite a number
of other factors involved as well, such as the control auhority excerted
by the front wheels on the salt, by the location of the center of
pressure and the actual amount of aero force trying to turn the car
sideways. In the next few monhs I am going to try and develop a
model that can be generally used by lsr folk to try and get some
understanding on how their car handles and how it gets into the
situation of a skid or spin to begin with. Since I am older than dirt,
it is taking me a bit longer to rouse up enough brain cells to attack
this issue, but hang tight...
I wil try and include the effects of the center of pressure, the aero
forces involved, the center of gravity, wheel base, corner weights, the
forces exerted by teh contact patches, and the PMOI.
anyone have comments regarding tis topic lemme know in a pm, as no need
to bother the entire list
mayf
_______________________________________________
Support Team.Net http://www.team.net/donate.html
Land-speed mailing list
http://autox.team.net/mailman/listinfo/land-speed
|