I am confused about something. On page 131 of the N2 manual it
explains understeer and oversteer. It describes oversteer as
"The car begins to "fishtail" as the rear end swings toward the
outside. This is caused by a lack of weight or downforce at the rear
end."
Would'nt lack of weight in the rear end make the car push.
I always thought that adding weight to the rear will make the car more
loose.
Could someone please clarify this.
Sam Bonsett
I'm not an expert on racing or anything, but I was under the impression
that the more weight you have towards the rear the more your rear tires
are less likely to loose grip. The weight keeps the tires on the track.
That's what I always thought anyway.
Sean Higgins (Higgy)
To some extent this is true. An increase of the normal force on the rear
wheels will increase the maximum lateral force that the tires transmit to
the rest of the car, whether that normal force comes from weight
distribution or aerodynamic effects. The weight distribution (front/rear)
has an effect that at first may seem paradoxical in terms of tight vs.
loose. Consider two situations:
1) Car CG is even with front wheels. Side forces on the front tires
produce no net torque on car. Side forces on the rear tires produce a net
torque about the CG which oppose the turn. A tight condition.
2) Car CG is even with rear wheels. Side forces on rear wheels produce no
net torque on car. Side forces on the front tires produce a net torque
about the CG which acts in the same direction as the turn. A loose
condition.
Placing the CG anywhere inbetween will yield varying degrees of
tight/loose.
Hope this helps.
--Bob Russell
Quoted text (30 lines)
> > I'm not an expert on racing or anything, but I was under the impression > > that the more weight you have towards the rear the more your rear tires > > are less likely to loose grip. The weight keeps the tires on the track. > > That's what I always thought anyway. > > Sean Higgins (Higgy) > To some extent this is true. An increase of the normal force on the rear > wheels will increase the maximum lateral force that the tires transmit to > the rest of the car, whether that normal force comes from weight > distribution or aerodynamic effects. The weight distribution (front/rear) > has an effect that at first may seem paradoxical in terms of tight vs. > loose. Consider two situations: > 1) Car CG is even with front wheels. Side forces on the front tires > produce no net torque on car. Side forces on the rear tires produce a net > torque about the CG which oppose the turn. A tight condition. > 2) Car CG is even with rear wheels. Side forces on rear wheels produce no > net torque on car. Side forces on the front tires produce a net torque > about the CG which acts in the same direction as the turn. A loose > condition. > Placing the CG anywhere inbetween will yield varying degrees of > tight/loose. > Hope this helps. > --Bob Russell> > > I'm not an expert on racing or anything, but I was under the impression
> > > that the more weight you have towards the rear the more your rear tires
> > > are less likely to loose grip. The weight keeps the tires on the track.
> > > That's what I always thought anyway.
> > > Sean Higgins (Higgy)
> > To some extent this is true. An increase of the normal force on the rear
> > wheels will increase the maximum lateral force that the tires transmit to
> > the rest of the car, whether that normal force comes from weight
> > distribution or aerodynamic effects. The weight distribution (front/rear)
> > has an effect that at first may seem paradoxical in terms of tight vs.
> > loose. Consider two situations:
> > 1) Car CG is even with front wheels. Side forces on the front tires
> > produce no net torque on car. Side forces on the rear tires produce a net
> > torque about the CG which oppose the turn. A tight condition.
> > 2) Car CG is even with rear wheels. Side forces on rear wheels produce no
I thought about it and stick to my guns:
Consider a left hand turn:
Car CG up front: Force on tires to the left, net torque to the right
Car CG in back: Force on tires to the left, net torque to the left
This is consistent with the sim, as well it should be.
Also, think about it in relation to handling characteristics of passenger
cars. Old big block Detroit iron used to plow like crazy and had front CG,
while mid or rear engine cars, like the Corvair, had the reputation of
being very loose.
--Bob Russell
