Introduction to High-Performance DrivingWelcome to the National Capital Chapter's drivers' school program. Our drivers' schools are designed to teach you the techniques of high-performance driving and give you valuable skills that you can apply directly to your daily driving. The goal of our program is to produce the most highly proficient drivers possible. This introduction is your first lesson. It presents the purpose of the
school, explains techniques that you'll learn, and defines terms that we'll use
in discussing high-performance driving. Please read it carefully.
There will be no "final exam" at the end of the school. We hope that you
will never be faced with a final exam, but if you are, it will happen somewhere
on the public roads, where you'll have to make quick maneuvers to avoid a
disaster. Should that situation occur, we hope that what you learn at the
drivers' school will help you get through it unscathed. Purpose
We conduct our drivers' schools for two reasons. Our primary objective is to teach you the skills necessary to control your car under all possible conditions. To that end, we want you to discover and understand your car's behavior under a variety of circumstances. This is vitally important should you ever need to call upon your skills in an emergency on the track or on the highway. If you're like most of us, you'll find that your effectiveness in controlling your car is limited initially by your skills rather than your car's capabilities. Modern cars are particularly well adapted to holding the road, and you'll find that your car's limits of adhesion are quite beyond what you had imagined. However, those limits are finite; when you do exceed them, you're likely to be traveling at high speed and therefore to have minimal time to react. That's why we're going to focus on building your skills faster than you build your speed.
Your first few sessions on the track are designed to show you how your car reacts to your inputs (acceleration, braking, and steering). You'll find that how you drive has a large effect on how your car behaves. You'll also find that where you drive on the track, i.e., the path you choose to drive as your car negotiates a curve, directly affects how fast and how safely you can take that curve.
Later in the school, you'll be able to apply the skills you've learned as you drive the track at higher speeds. Summit Point, like most "road courses," contains examples of many of the conditions you encounter on public roads--left- and right-hand curves of different radii, uphill and downhill stretches, and changing pavement.
The secondary purpose of the school is to give you a chance to enjoy driving your car under controlled conditions. You'll be able to exercise your newly developed skills in ways you cannot do on the street. You're likely to find, as we have, that precision driving is a lot of fun. As a by-product, you'll have much more confidence in your driving abilities at the end of the event, and you'll be a much better street driver as well.
One thing that our drivers' school will not teach you is how to race. There will be no racing at any National Capital Chapter drivers' school. If you try to race at the drivers' school, your school experience will be over, as we won't let you back on the track. You should feel no affront to your pride if another car passes you; in fact, you should help him or her get around you. Your sole concern in driving the track is to practice putting your car at precisely the right spot to negotiate the curves, not to beat another car to the next corner.
It's important to realize that no one drivers' school will teach you everything you need to know to become a superlative driver. Acquiring driving skills is a process which typically spans several years and dozens of schools. While it is easy to gain confidence quickly, recognize that overconfidence coupled with high speeds can lead to trouble. Don't rush yourself; plan for the long term and pace yourself throughout the school.
Driving Theory
You've probably lost control of your car at some point in time. Perhaps it was raining or snowing; you entered a curve a little too fast, turned the wheel, but your car kept going straight ahead. Or maybe you had to jam on your brakes suddenly and hope that you'd stop before hitting the car in front of you. In any case, you know that helpless feeling of being "along for the ride" with no control over what's happening.
What went wrong, of course, was that you asked your car to do something it couldn't do, either negotiate a curve at too high a speed or come to a stop in too short a distance. Physical laws govern the behavior of your car, and understanding those laws is the key to controlling your car. At the drivers'
school, we'll show you--and let you experience--the physical limits of your
car's ability to turn or stop. Most importantly, by experiencing and
understanding these limits, you'll know what options you have in an
emergency.
Curves
Fundamentally, driving is all about friction: specifically, the friction
between your tires and the pavement. When you depress the accelerator, or the
brake pedal, or turn the steering wheel, your tires generate frictional forces
which are applied to your car to accelerate, decelerate, or change directions.
Each specific demand you make on your car (turning a corner, for example)
requires a certain amount of force. If your tires cannot generate sufficient
frictional force, your car will not do what you command.
Consider the series of curves below (called an "S curve"). If you follow the
shape of the curve, your path will be something like this:

However, if you "straighten out" the curve (called apexing the
curve), your path will be like this:

Your car requires the least amount of friction with the pavement when
traveling in a straight line at a constant speed. Accelerating, braking, or
turning require more friction, with larger speed or direction changes (e.g.,
braking harder or turning sharper) requiring correspondingly larger amounts of
friction. Because you are ultimately limited by the friction available, you can
go faster (or have a larger safety margin at a given speed) if you lessen your
car's frictional requirements. Apexing a curve reduces the friction required by
reducing the amount you are turning.
Every curve follows part of the circumference of one or more circles, and
the radius is the distance from the center of the circle to the curve
itself. A curve that follows the circumference of just one circle is called a
constant-radius curve. Here is an example:

Note two things about this curve. First, the radius remains constant
throughout the curve, and the apex--the point at which the path your
car takes comes closest to the inside of the curve--is halfway through the
curve. Second, the driving radius is larger than the curve
radius; this is a consequence of apexing the curve. Turn 3 at the Summit
Point Main Circuit is an example of a constant-radius curve (a curve on a track
is called a turn or a corner).
Another type of curve is the increasing-radius curve:

Here, the radius of the curve as you enter it is smaller than the radius of
the curve as you exit. The apex occurs earlier in the curve. The Summit Point
Main Circuit's Turn 1 is an increasing-radius curve.
There's also a decreasing-radius curve, where the radius as you
enter is larger than the radius as you leave:

The apex of a decreasing-radius curve occurs later in the curve. When run
clockwise, the Summit Point Jefferson Circuit's Turn 4 is an example of a
decreasing-radius curve.
We've mentioned an S curve, which is a curve in one direction
followed by a curve in the opposite direction, forming the shape of the letter
S. At the Summit Point Main Circuit, Turns 7-9 form a pair of S curves, as do
Turns 1-3 at the Jefferson Circuit.
We'll use some standard terms in talking about curves. The braking
point is the point at which you begin to slow your car down enough to
negotiate the curve. The turn-in point (or entry point) is
where you turn your steering wheel to begin the curve. The entrance is
the path you take from the turn-in point to the apex. The apex is the
point of your closest approach to the inside edge of the road. The
exit is the path you take from the apex to the track-out point
(or exit point), which is the point at which the curve ends.
The most common error made when negotiating curves is turning the steering
wheel before the turn-in point. This results in your car following a path that
touches the inside of the road before the proper apex. This error is called an
early apex. If you do the geometry, you'll see that the track-out
point of an early-apex path is off the outside of the paved surface. To avoid
running off into the grass, you will have to tighten your path. The earlier in
the turn you detect your error and apply correction, the less additional
steering will be required to return the track-out point to the pavement.
The opposite error, that of turning the steering wheel after the turn-in
point, results in a path that touches the inside of the road after the proper
apex; this is a late apex. Late apexes are inherently safer, because
the path leads to a track-out point inside of the edge of the pavement. Note
that a late-apex path is still tighter than a correct apex, so your car is
still working harder than it should. You should strive to apex properly, but
late-apex errors are better than early-apex ones.
Threshold Braking
In order to negotiate most curves, you'll need to reduce your speed very
rapidly while maintaining full control of your car. The quickest way to slow
down is called threshold braking. This means applying the brakes as
hard as possible but just shy of the point where your wheels would "lock up"
(i.e., where the wheels stop turning and the car slides). It is difficult to
modulate precisely the amount of pressure you apply to the brake pedal, and
it's even tougher if you're trying to turn the car at the same time. However,
if you brake with the ball of your foot, you'll have a lot more control.
If your car is equipped with an antilock braking system (ABS), you can
always just mash down on the brake pedal and let the ABS do all of the work for
you. However, true threshold braking, i.e., applying maximal braking just
before the ABS kicks in, will result in slightly shorter braking
distances. Therefore, you should learn and practice threshold braking by
modulating the pedal pressure to keep the ABS from activating.
Handling
Two important aspects of your car's handling are balance and
weight transfer. Balance is how your car's weight is distributed from
front to rear and from side to side. The weight of your car generates
proportional frictional forces (i.e., grip) at each tire, and these
forces change profoundly when you accelerate, decelerate, or change direction;
this is called weight transfer.
When you accelerate, weight transfers to the rear of your car, decreasing
the grip available to your front tires and increasing the grip available to
your rear tires. When you decelerate, weight transfers to the front of your
car, enhancing front tire grip and decreasing rear tire grip. In a turn, weight
transfers to the outer tires, reducing the grip of your inner tires. The amount
by which grip changes at each tire in response to weight transfer is determined
primarily by your car's suspension and its reactions to your inputs.
For a given corner taken at a given speed, each of your tires requires a
certain amount of grip to maintain adhesion with the pavement. Higher speeds
and tighter corners require correspondingly more grip. If weight transfer
causes the grip available at a given tire to decrease below that which is
required, it will lose adhesion and begin to slide against the pavement. If the
sliding tire is at the front of your car, your car will understeer; if
it is at the rear, your car will oversteer.
Understeer, also called "push" or "plough," occurs when your front
tires lose adhesion with the pavement. Instead of following your intended path
around the turn, your car will begin to run wide, as though you were steering
less than you needed to. Understeer is often caused by entering a turn too fast
or by turning the steering wheel too quickly: both upset the balance of your
car.
The important thing to realize is that understeer occurs because your front
tires are overloaded; they require more grip to maintain adhesion than is
available. Steering more, i.e., trying to turn a tighter arc, simply overloads
them more, making the understeer worse. To correct understeer, you must restore
adhesion to the front tires by slowing your car and/or straightening the
steering wheel; both reduce the grip required. Straightening the wheel is
counterintuitive, because you're deliberately steering toward the outside edge
of the pavement, but you must regain front-end adhesion before you can
change your car's direction.

In "terminal understeer," the front wheels lose traction, and the car
continues going straight ahead.
Oversteer, or "looseness," occurs when your rear tires lose
adhesion with the pavement. Instead of following your intended path around the
turn, your car will begin to rotate around your front tires, as though you were
steering more than you needed to. To stop the rotation of your car around its
front wheels, you must apply a countering force by steering toward the outside
of the turn. You must also maintain your speed or accelerate slightly. This too
is counterintuitive, because the last thing you'll think you need at that point
is more speed. However, when you accelerate, you transfer weight back onto your
rear tires, giving them more grip. It's important to recognize here that you're
applying acceleration not to increase your speed, but to restore your car's
balance.
Oversteer is often caused by sudden deceleration in a turn, either by
braking or by coming sharply off the accelerator, causing weight to transfer
away from the rear wheels. This often occurs when you enter a turn too fast;
the solution is to enter more slowly, so that you can maintain your car's
balance throughout the turn.
Oversteer in a rear-wheel drive car can also be caused by applying enough
acceleration to break the rear wheels loose. This occurs most frequently under
conditions of reduced adhesion (rain), but it can also occur under good
conditions if your car is powerful enough. In this case, you must reduce your
acceleration slightly to allow your rear tires to re-adhere. If you
reduce your acceleration too much or too rapidly, weight will transfer away
from the rear, and your car will continue to oversteer. To avoid inducing
oversteer, it's important to apply acceleration smoothly and progressively.
Remember: anything you do to upset your car's balance may transfer enough
weight to cause understeer or oversteer. That's why we will emphasize
smoothness throughout your school.

In "terminal oversteer," the car's rear wheels lose traction and cause the
car to spin.
If you experience terminal understeer or terminal
oversteer (the "terminal" in this case doesn't mean "fatal," but rather
"uncorrectable"), and you're going to go off the track, do not
try to force your car to stay on the track. Instead, straighten your steering
wheel and drive off the track under as much control as you can manage. It is
far more important to maintain control than it is to stay on the paved
surface.
Where to Look
Whenever you're driving, you should watch where you're going. This
seems to be obvious, but you'd be surprised how much time you spend looking at
where you are--at your hood or at the bumper of the car in front of you, for
instance. On the track, as on the Interstate, things happen with great rapidity
at high speeds. To avoid problems, you must have as much advance warning of
potential trouble as possible, and that means looking as far ahead as
possible. By doing so, you will be able to anticipate trouble and thereby
keep yourself safe.
As you become familiar with the track and its turns, you'll naturally
develop reference points to guide you around the track. Initially, you'll find
yourself concentrating very hard on these reference points: look at the braking
point, look at the turn-in point, look at the apex, and so on. Chances are,
you'll still be looking at the turn-in point as you begin to turn the car. The
technique to develop is to look at where you want to go, not at where you are.
This is called ocular driving. If you look ahead, you'll find
your driving becomes much smoother, and with smoothness comes both safety and
speed.
Speed, in and of itself, is not dangerous. You may be in more danger driving
30 MPH on a foggy two-lane road at night than driving 70 MPH on the Interstate
on a clear, sunny day. Increasing speed does, however, reduce your available
reaction time. That's why it's crucial to extend that time as much as
possible by looking as far ahead as possible, consistent with driving
accurately. The faster you go, the farther ahead you must look to maintain the
same safety margin.
After you've mastered looking ahead, the next technique to master is
enlarging your field of vision. If you're looking ahead at the apex, you
probably won't see the flagger off to your right. If you're concentrating on
the next braking point, you may not notice the car overtaking in your rear-view
mirror. By expanding your field of vision, you'll find you are much more aware
of all your surroundings--not just the next reference point, but the next two
or three reference points. Again, this will make your driving smoother. In
addition, if you're taking in more than just the next braking point, you may
notice the car in front of you getting loose in the turn, or you may notice the
sheen of oil at the turn entry, thereby knowing that you need to do something
immediately in order to avoid disaster.
Putting It All Together
When you're driving the track at Summit Point--and anytime you're driving
rapidly and skillfully--you need to combine your knowledge of cornering,
braking, and accelerating into a smooth, flowing process. If you concentrate on
and practice driving smoothly, speed will follow naturally. If your actions are
abrupt, and you try to force your unbalanced car into corners, you'll find it
very frustrating and difficult to develop any sense of rhythm. You will also
never develop any speed.
What follows are brief discussions of some of the techniques you'll be
taught at the drivers' school. If you practice these driving techniques, you'll
find that driving fast is comfortable and enjoyable.
Ocular driving--Look where you want your car to go, rather than
where your car is now. If you're entering a turn, look at the apex. If you're
at the apex, look at the exit. If you're driving down a straightaway, look well
ahead toward the next turn. If you do this, you'll find that you automatically
steer the car toward where you want it to go. You'll also find that your inputs
are much smoother, as your brain will be registering a larger time context. If
you look just at the road immediately in front of you, you won't be prepared
for the next turn or obstacle. In addition, it's a good idea to keep an eye on
your rear-view mirrors. If you're completely aware of everything that's going
on around you, you can avoid surprises.
Braking and downshifting--As you approach a turn, do all of your
braking and downshifting while you're still traveling in a straight line. Then,
as you enter the turn, you can concentrate on steering the car toward the apex
and maintaining the balance of your car throughout the turn. Make sure you've
released the clutch before you begin to turn; otherwise, you may unbalance your
car.
Entering a turn--As you reach the turn-in point, look to the apex
and steer your car toward it. Maintain your car's balance with a light pressure
on the accelerator until your car has successfully transitioned into the turn.
Your path from the turn-in point should be a smooth arc; if you have to "saw"
your steering wheel back and forth, or if you're still on the brakes, then
you've entered the turn too fast. Remember that speed into a turn isn't
important; balance is. You will exit far more quickly and under far better
control if your entry is slow enough to "settle" your car on its suspension
immediately after turn-in.
Apexing--As you approach the apex of the turn, look ahead to the
track-out point. Start accelerating gently at the apex. If you've entered the
turn properly, the car will head toward the exit almost effortlessly.
Exiting--As you approach the exit of the turn, look ahead to the
next turn or down the upcoming straightaway. Keep accelerating steadily and
begin to steer the car toward your next "mark," as needed.
These techniques aren't the only way to handle your car, but they're a good
start. Once you've mastered them, you can move on to more advanced
techniques.
End of Lesson One
The most important point to keep in mind is that in order to go fast you
must control your car at all times. The less you upset your car, the smoother,
safer, and faster you'll be able to go. Remember, it's the laws of physics that
determine what your car can and can't do; if you try to break those laws,
you'll get caught every time, and the penalty you pay can be very high.
Your classroom and in-car instructors will discuss driving techniques in
more detail. If you have questions at any time, please don't hesitate to ask
either of them. We understand that you might be embarrassed to ask, but
remember that it will aid your learning--and will make our jobs easier--if you
ask whenever you are unsure.
Freude am fahren!
Revised March 2000
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