rec.autos.simulators

After reading the manual, I think I'm now confused as to the affect of the
shock stiffness. Manual goes into theory of weight transfer to tires....as
more weight on tire gives MORE grip, less gives less due to increase or
decrease in contact patch, respectively.  But the section on shocks states
that a stiffer shock puts more weight on that tire thus it will lose grip
sooner.  Isn't this contradictory?  I'm also finding the anti-roll bar
settings tricky....manual says to keep the rear less than the front, so
that front will loose grip first and be "pushy" rather than oversteer.
But I find that if I have oversteer, making the rear softer at best
doesn't make any diff. or makes it worse. Is this likely due to a
completely out of wack car setup or is there better ways to set the roll?

Just to give me some encouragement, can somebody tell me 179.5 mph at New
Hampshire under qualifying conditions is reasonable?

Ok, from a vehicle dynamics point of view...  Increasing the anti-roll
bar _decreases_ the ability of that axle to corner.  So if your car is
"pushing" (understeering) you would want to decrease the stiffness
of the front bar relative to the rear bar.

The anti-roll bar is, in effect, an additional stiffness to the already
existent stiffness of the shocks.  So if you are adding a lot of shock
at a particular axle, _in one way_, this will decrease the cornering
ability of the axle.  There are a lot of other factors that enter into this,
though, like the tire contact patch, etc.

Ouch, hate to burst your bubble, 179.5 isn't very close.  Try more for a
182+; the records, I believe, are around 185.  In order to get those speeds,
you're going to be a lot more "on the edge", though....

Mark Anderson

In a general sense, that is correct.  The reason is that a roll bar, will do two things:

1.) Increase Weight transfer on the axle to which it is applied.  It
    accomplishes this by resisting rolling of the vehicle in the corners.
    The net result of the resistance is that the outside tire in a corner
    is more heavily loaded as the antiroll bar is increased.  This also
    has the effect of decreasing the loading on the inside tire on that
    same axle.  This in itself would imply that adding roll bars is bad.

2.) Decreasing roll angle of the car.  Excessive roll angle can cause
    undesirable camber changes.  By limiting the roll angle of the car,
    the camber changes are also minimized.

You can see the effects of adding roll bar by increasing the resistance
a roll bar while negotiating a oval track, as you increse the stiffness
you will see the outside tire get hotter and the inside tire cool down.

Another advantage of increasing the anti-roll bar rate is that
additional roll stiffness can be had without significantly affecting
the ride quality (which isnt really a consideration at all with a
simulator).

Anyway enough babbling!