[DeTomaso] Pantera Width vs GT4 GT5

Jason Eaton jason.eaton at gmail.com
Mon May 26 12:34:01 EDT 2008


Goran dont we have to consider the moment force around the CG point
and if so then a wider track would mean more force necessary to unload
the suspension on either side.

At the open road race 150mph, as the wind was blowing me around from
the side of the car, I thought it would be nice to not drift across
one lane of traffic at these speeds. Back to your flinstone car, if
you apply a side force to the passenger door there is some moment
around the driver's side tire and the longer the distance from
driver's side to passenger side the larger force required to push that
flinstone car up onto two wheels.

If the above is true, then would it not be similar as the car moves
down the road and side loads are applied to the tires because we are
really floating down the road and its hard to prevent instant loading
of the passenger or the drivers side tires, a wider track would be
helpful in those situations as well?

Thanks again for your thoughts.

On Mon, May 26, 2008 at 12:01 AM, Göran Malmberg
<hemipanter at hemipanter.se> wrote:
> Lets see if I can come up with an explanation that makes a picture
> of how it works.
> If we putt all driversfeeling of carbehaviour aside and only look at
> the car:s cornering power. I can say that A-arms and geometry has
> nothing to do with it. To explain what I mean with such statement
> lets assume that we have a very simple car, a square cube with a
> wheel hold by a single bolt each corner, sort of a Flintstone car.
> Attach a wire on the middle side of the body at CGH at pull it
> sideways. Lest assume it takes 1G compared to its weight. To get
> better numbers we will need a rubber that gives a higher number of
> friction.
>
> A higher number of friction could be had in many ways,
> temperature, another rubber, another weight to rubber contact
> area to to load relationship, etc.
>
> If we keep the 1g rubber an put an advanced suspension system on
> the car, instead of the Flintstone bolt stuff, the suspension will make
> the chassis to create a roll motion, and the tires to describe a camber
> pattern that together makes the tires no longer to stay vertical thereby
> loosing grip. We will see a 0,98g number then.
>
> So, whats the trick having a suspension system on the car then if it makes
> things worse? The "Zerocar" will only be fast if the track is 100% flat and
> the turning radious is keept 100% steady state. A condition that hardley
> exist.
>
> What a good suspension do is to transform a dynmic situation, that is
> loading the tire contact patch of the zerocar uneven, in to a more evenly
> loaded situation. Trying to make the tires to experience a 100% flat and
> 100% steady state situation (althrought it is not) as much as possible.
>
> A passenger car is built to meet a number of weather and road conditions.
> What makes a racecar faster is that it can be built to handle one single
> codition much better. On the other hand it might be terrible in snow, if not
> built for snow.
>
> Goran
>



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