What is the skidpad
The skidpad is the test track in NFS:PU, used during factory driver,
but can also be used to test drive a car. The real skidpad is
the inner circle, but to test a car you want to drive on the outside
circular track.
"lift throttle oversteer"?
Lift throttle
By lifting your foot off the throttle, some engine braking force
is induced.
Oversteer
As I used it in the expression "lift throttle oversteer", oversteer is
when the back end of a car slides outwards, causing the car to turn
inwards while cornering. This is a common usage, but not technical,
see below.
In the case of NFS:PU, you can setup the cars so that they "oversteer"
a bit when you lift the throttle while turning at the limits of traction.
The cars slow down, but also keep turning inwards, which results in
a decreasing radius direction of travel. With a "non-oversteer" setup,
the result of trying to slow down when at the limits results in the radius
remaining the same or getting bigger, and the car goes off track. With
the oversteer setup, you can enter a corner faster, then lift off the
throttle so the car slows down and turns tighter, improving corner entry
phase speeds.
With a rear wheel drive car, all of the engine braking is applied at the
rear tires, so the car has a natural tendency to oversteer already, usually
too much in NFS:PU, so you need to reduce this by adjusting the toe slider
to the left. With a 4 wheel drive car, the engine braking occurs on all 4
tires, so you need to reduce rear wheel grip relative to front wheel grip
in order to get the 4 wheel drive cars to lift throttle oversteer. Usually
moving the toe in slider all the way right isn't enough, so you run the front
tires at 45 psi (maximum cornering grip in NFS:PU, not in real life), and
the rear tires at a slighly lower pressure, like 41 to 43 for the 911's, or 38 to
41 for the GT1.
On some race cars, like the cars modeled in Grand Prix Legends, the rear end
differential has a seperate locking factor for when the engine is accelerating
and for when the engine is decelerating a car. This can be used to modify
the oversteer reaction of a car to throttle inputs. NFS:PU doesn't model this.
More accurate oversteer definitions:
The technical definition is when the rear tires have less slip angle
than the front tires. The front tires have to be steered slightly
outwards (relative to the car, not to the direction of travel), for
a true oversteer condition to exist.
"Oversteer" in reference to the setup of a car. A car is driving at
moderate speed in a circle, and gradually speeds up. As the car
speeds up and nears the limits of traction, the driver may need to
change the steering input in order to maintain the same turning
radius. Typically in a street car, the steering input is increased,
meanging that the front tires have to be turned further inwards, and
the setup is called "understeery". If the steering input remains the
same, the car is considered neutral. If less steering input is
required, then the setup is called "oversteery". If the driver has
to completly center the steering, so both front and rear wheels
are parallel and all have the same skid/slip angle, this is considered
to be a "critical oversteer" setup. In the case of a car on a sliding
surface, you can go beyond this where the front tires have to be
turned outwards relative to the car, but there's no special term for
this, except for the technical definition of oversteer.