Re: need a definition..!! (vw_golf)
Whenever you drive around a corner at speed, all the tires slip sideways a little.
This means that the direction the tire is pointed is not the same as the direction
that it's actually travelling. The angle between the two directions, is called the slip
angle. All four tires have a slip angle during a turn.
Understeer is when the slip angle of the front tires is greater than that of the rears.
Oversteer is when the slip angle of the rear tires is greater than that of the fronts.
That's the *official* definition.
From a more down to earth point of view, understeer is when you turn the
steering wheel into the turn more and the front of the car seems to continue
to go straight, or not turn any sharper. Oversteer is when the rear end of
the car swings out more than the front, and if left to its own devices
tries to overtake the front.
The more entertaining definitions from racers are.
"Understeer is when you hit the wall with the front of your car first."
"Oversteer is when you hit the wall with the back of your car first."
or
"Oversteer is when the passenger is afraid."
"Understeer is when the race driver is afraid."
In general front wheel drive cars carry most of their weight up front
so their front tires have to do more work, and thus they tend to
slip more than the rears, and thus their tendency is to understeer.
A GTI-VR6 has about a 65/35 front/rear weight distribution. It pushes badly
without a bunch of suspension mods. To make a car like the GTI-VR6
feel more neutral you try to increase the lateral grip at the front (tires,
controlling the camber angle with springs and sway bar), and you typically
try to decrease the rear lateral traction with a larger rear swaybar
which tends to lift the rear inside tire completely off the ground. Now
the rear slip angle matches that of the front (a lot at both ends), and
the car *feels* more neutral. Lift off the throttle and the grip increases
at the front, and you may even get lift throttle oversteer.
There ya go.
ian
Whenever you drive around a corner at speed, all the tires slip sideways a little.
This means that the direction the tire is pointed is not the same as the direction
that it's actually travelling. The angle between the two directions, is called the slip
angle. All four tires have a slip angle during a turn.
Understeer is when the slip angle of the front tires is greater than that of the rears.
Oversteer is when the slip angle of the rear tires is greater than that of the fronts.
That's the *official* definition.
From a more down to earth point of view, understeer is when you turn the
steering wheel into the turn more and the front of the car seems to continue
to go straight, or not turn any sharper. Oversteer is when the rear end of
the car swings out more than the front, and if left to its own devices
tries to overtake the front.
The more entertaining definitions from racers are.
"Understeer is when you hit the wall with the front of your car first."
"Oversteer is when you hit the wall with the back of your car first."
or
"Oversteer is when the passenger is afraid."
"Understeer is when the race driver is afraid."
In general front wheel drive cars carry most of their weight up front
so their front tires have to do more work, and thus they tend to
slip more than the rears, and thus their tendency is to understeer.
A GTI-VR6 has about a 65/35 front/rear weight distribution. It pushes badly
without a bunch of suspension mods. To make a car like the GTI-VR6
feel more neutral you try to increase the lateral grip at the front (tires,
controlling the camber angle with springs and sway bar), and you typically
try to decrease the rear lateral traction with a larger rear swaybar
which tends to lift the rear inside tire completely off the ground. Now
the rear slip angle matches that of the front (a lot at both ends), and
the car *feels* more neutral. Lift off the throttle and the grip increases
at the front, and you may even get lift throttle oversteer.
There ya go.
ian
