SEM Drivers Handbook

 

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“Porsche motoring is and always will be driving in its purest form.” Ferry Porsche

Special Thanks to……………………………………..Jerry McDermot
Special Thanks to…………………………………………….Jeff Amos

Table of Contents:

A. Proper Seating for Maximum Awareness and Car Control
B. Heel and Toe Downshifting
C. Under-steer and Over-steer (cause and correction)
D. Trailing Brake Technique
E. Explanation of General Terms in Racing and High Performance Driving
F. Advanced Street and Highway Driving
G. Techniques
I. Notes & Tack Diagram
SMOOTHNESS! CONSISTANCY! CONCENTRATION!

We will stress these words here again and again!! Every technique you will learn here should be executed smoothly and consistently. To achieve this, you will have to concentrate 100%.

Four tire patches are the only contact areas you have with the road while driving your car. (Tire patches are the part of the tires that touch the road.) You will learn to be sensitive to and read the signals that are picked up by tires and transferred to the wheels, suspension, car seat, and then, in turn, to the steering wheel and pedals such as throttle, clutch and brake.

You will learn to work with your car as one unit and will also learn to consider it less “your living room on wheels,” but a machine that needs to be driven with alertness, awareness, and constant preparation for emergency situations.

The following will introduce you to some simple and some very complex techniques and ideas, which will help you, become a better street driver or race driver.

A. PROPER SEATING FOR MAXIMUM AWARENESS AND CAR CONTROL

1. Car Control:
This is the ability to drive a vehicle with maximum control at all times under any situation. It requires awareness of your surroundings including other vehicles on the road, road conditions, potential problems or accidents. Under all conditions, you have to understand some basic areas of car control and weight transfer. When you drive a car, you are moving weight under your control. The weight of the car rests on four tire patches. This is the only area of contact between the road and your vehicle. Under braking, as you transfer weight to the front tires, the front tire patches Increase in size.

Under acceleration, as the weight transfers to the rear of the car, the rear tire patches increase in size. When entering a corner, you want the maximum size of tire patches on your front wheels to provide maximum adhesion and better steering control. To get this, you slowly ease the brake pedal pressure off as you turn the wheel into the first one- third of the corner.

You then apply your throttle gently to transfer the weight to your rear tires to prevent the rear of your car from spinning while you are exiting the corner. You should avoid any abrupt input of brakes or throttle because you are then upsetting your car’s stability. Any abrupt weight transfer can cause a spin or slide and can cause you to lose control of the car.

 

2. Proper Seating:
The buttocks should be tucked firmly against the lower back of your seat. With your back erect and against the seat. This seating position will keep you alert and the total contact of your body with your seat will feed back valuable information to you about the road conditions, your car’s suspension and tires. The distance between your steering wheel and seat should allow your arms to be comfortably bent when you hold the steering wheel. This will allow you to react quickly with full use of your arms in case of emergency evasive maneuvers, and will also be less tiring on your arms.

3. Proper Position for Hands on Steering Wheel: Your arms should be slightly bent at the elbow (refer to proper body placement for your car seat) with your hands located in the 3 and 9 ‘o clock position on the wheel with thumbs resting on top of the spokes. Holding your steering wheel in this fashion will allow you to sense first-hand information fed to you through your steering column into the wheel. You will find that you have more strength available while maneuvering your car. Your arms will get less tired, and in case of emergency evasive maneuvers, you will have all that extra strength to help you. Let both hands do the work! While one pulls, the other can push the wheel smoothly!

4. Feet and Legs: Picking up vibrations from the brake, clutch and throttle pedals are also very important. Use the ball of your foot on the brake pedal, with your heel off the floor so you can feel the pressure you apply. This allows you to feel when the brakes are beginning to lock up the wheels. Legs should be slightly bent when fully extended to the pedals so you don’t have to stretch the legs and feet. Smoothness is very important. Any sudden input of brake, throttle, clutch or steering will cause sudden weight transfer in your vehicle and lessen your car control. It may also start a skid or accident!

5.Seat Belt: Your lap and shoulder belts should be fairly tight with just enough room to allow you to reach the dashboard controls. Seatbelts are important for several reasons. They will hold you in place and keep your body tucked into your seat for maximum feel and feedback. In case of emergency evasive maneuvers, they keep you in place behind your steering wheel, instead of having you slide around the front seat. They will keep you from hitting the steering wheel or windshield in case you have an accident.

 

B. HEEL AND TOE DOWNSHIFTING

1. Shifting: Cup your hand on top of the knob and gently guide it into first gear with the heel of your hand. Now, use your fingers to move it into second gear and then into third gear. Now, gently ease it into fourth gear. Treat the gearshift lever knob gently as if it were fragile, like an eggshell. Don’t grab or yank it into gear. You may get into the wrong gear or destroy your transmission. Most transmissions shift smoothly if you just guide the shift lever into the proper gear in a smooth manner.

2. Heel and Toe Downshifting: This is the technique of operating the brake and gas pedal simultaneously with the right foot while clutching with the left foot. If your car has an automatic transmission, this does not apply to your kind of driving. Heel and toe downshifting allows you to brake and match the engine rpms with rear wheel rpms which allows for smooth downshifting. Here is how it is done! First you start to squeeze on the brake pressure to slow down the car. Then pivot the heel or side of your right foot onto throttle, maintaining even brake pressure. Depress the clutch with your left foot, moving the shift lever into neutral on your way to the next gear. On releasing the clutch halfway, squeeze the throttle on to bring up the engine’s rpms. Depress clutch again, quickly, and shift into the next lower gear. Release the clutch smoothly, then pivot your right heel off the throttle back to below brake pedal and continue trailing brake. This technique is called heel and toe downshifting with double clutching.

C. UNDERSTEER AND OVERSTEER (cause and correction)

1. Understeer- a front wheel skid:
Cause: 1. Too much speed in a corner in an inherently understeering car
(front engine).
Correction: 1a. Correct by easing off throttle half a throttle setting to
transfer weight to the front wheels; add steering to get proper
line back. If need be, back off the throttle all the way and again
add the steering correction.
Cause: 2. Too much braking, which causes front wheels to lock.
Correction: 2a. Ease off brakes smoothly or reduce brake to get front
wheels unlocked (or rolling), add steering to get proper line
back.
Cause: 3. Violently spinning front wheels (front wheel drive car).
Correction: 3a. Ease off throttle to stop front wheels from spinning and to
transfer weight to front tires; add steering to get proper line
back. Then apply throttle progressively, adjusting as necessary.
2. Oversteer – a rear wheel skid or slide:
Cause: 1. Too much speed in a corner in an inherently oversteering car
(rear engine). Rear end slides out.
Correction: 1a. First add steering quickly into direction the rear end is sliding.
On dry pavement, add some throttle to transfer weight to the
rear wheels. When rear end starts coming back, correct steering
quickly into opposite direction to counteract second skid. As car
comes out of second skid, bring wheel smoothly back to straight
and continue on proper line.
Cause: 2. Braking too hard causing the weight to transfer abruptly
forward which causes the rear wheels to lock.
Correction: 2a. Come off brakes quickly and add steering as rapidly as
possible into the direction the rear end is sliding. When rear end
starts coming back, correct steering quickly again to gain back
proper line. Then add smooth throttle to help move the car in a
forward direction.
Cause: 3. Violently spinning rear wheels (rear wheel drive car).
Correction: 3a. Ease off throttle to stop rear wheels from spinning and
quickly add steering in the direction the rear end is sliding.
When rear end starts coming back, quickly add steering again
to gain back proper line. Then smoothly squeeze on throttle
to keep the car moving in a forward direction.

D. TRAILING BRAKE TECHNIQUE
This is a technique using the brakes as a handling device as well as a braking device. As you approach a turn, initiate your braking smoothly to transfer the weight forward, setting the chassis by compressing the shocks and springs, thus increasing the front tire patches. Efficient Braking is always done in a straight line just short of locking the wheels. However, instead of releasing the brakes as soon as you begin the corner, continue to use the brakes as you turn in for the turn. As your cornering force increases, your braking force should decrease. This technique keeps the outside front tire patch loaded allowing for better adhesion and therefore, allowing the car to better “point” into the turn, decreasing the tendency toundersteer. This technique used in conjunction with the proper “line” technique will make the car much more controllable and safer in a cornering situation.

E. EXPLANATION OF SOME GENERAL TERMS IN RACING AND HIGH PERFORMANCE DRIVING

Apex:

That point in a corner when the inside wheels are at the inside edge of the turn. This may be a long or a short distance.

a. If apex is too early, the road will be used up too soon as you exit the corner and/or the throttle cannot be applied as soon as it might for better exit speed out of corner.
b. If the apex is too late, all of the road will not be used and/or maximum power will not compensate for an excessively slow entry.
c. The proper late apex is illustrated and discussed later.

Line of Road Course:
Imaginary path of a car as It maneuvers around a track finding the proper apexes while using the entire width of the road to your best advantage and maximum speed.

Drifting: Car has lost traction and is gaining speed while running out of road. Sliding: Car has lost traction and is losing ground or running out of road.

Drafting: Following another car very closely in the “bubble of air” which that car creates. This makes it possible for you to achieve a higher rate of speed by lowering your wind resistance, and also allows you to save on fuel. This maneuver can be referred to as “Slipstreaming.”

Power Slide: Controlled slide with throttle, maintaining proper line through corner (used mainly on hairpins or slow turns).

Camber of Road: Positive Camber (a banked corner): Outside tires maintain excellent traction. In the event of loss of traction due to locked wheels or a spin, the car will go downhill. Negative Camber: The road is going away from you, thus causing loss of traction. This in turn, may cause a front or rear wheel slide.

F. ADVANCED STREET AND HIGHWAY DRIVING ROAD EMERGENCIES

BLOW OUTS:
Modern tires are not as subject to complete loss of air as tires were some years ago. Still, under certain circumstances, tires can and do blow out. This is the kind of driving emergency for which it is impossible to be completely prepared, since it comes with shocking suddenness, and with no advance clue that it is about to happen. As in all other emergencies, what you do will depend on the circumstances. Some general principles apply, however:

1. Don’t get on the brakes. It will be difficult enough to steer with one tire completely flat. Hard braking will only complicate matters at this point.

2. Don’t exert sudden hard Jerking movements on the wheel. This can put you into a spin.

3. If the traffic conditions allow such, you should continue bearing in the same direction the blow-out pulls you.
(Generally, the car will pull towards the side of the car on which the blow-out has occurred.) Alert other drivers with turn signals, and steer the car
off the roadway at the first safe spot to do so.

4. Don’t try to stop as quickly as possible in order to save the tire. It is already ruined. Save your life, and maybe the lives of others.

BRAKE FAILURE:
The sudden realization that your vehicle’s brakes are not working properly can be a terrifying experience. This is particularly true when you discover this condition
at the precise moment you most desperately need the brakes. We will be concerned here with types of brake failure, brake fade, and complete loss of
braking.

BRAKE FADE:
Brakes, when overused and consequently overheated, will begin to lose their braking efficiency. This situation will usually occur on a steep downgrade or in a
high speed run requiring frequent hard braking applications. When fade occurs, you may find yourself gaining momentum, even though the brakes are applied.

Your first consideration should be to get in a lower gear. If there is time, gently increase engine speed before shifting down to more closely match engine speed
to wheel speed. Apply the parking brake carefully. This engages the rear wheel brakes only, and since they usually run cooler than the front wheel brakes, they
may still have some braking power left. Meanwhile, your front brakes can be cooling somewhat, provided that you resist the urge to use the brake pedal.

Above all, don’t panic. Don’t get so engrossed in finding a way to brake the car that you forget you are still able to (and may be required to) steer away from
contact or hazards. When speed is reduced to a level safe enough to do so, get off the road. Allow the brakes to cool before attempting to move the car
again.

BRAKE LOSS:
This is one to turn your hair white! A mechanical malfunction occurs without your knowledge so that when you step on the brake pedal, nothing happens.

Here again, the situation will dictate what you must do first. If you are approaching an obstruction, a pedestrian, another vehicle, or a busy intersection, you will
have to make an almost instantaneous decision. It may be best to concentrate on your steering and the power of your engine to get out of the situation and
over to a spot where you can try to stop the vehicle.

On the other hand, it may be that you will be best advised to apply the parking brake as hard as possible, drop to the lowest gear available to you and look for
the nearest escape route. You may even have to decide which of several obstructions you wish to hit!

In any event, once the car is stopped, do not even consider using it further for any distance until the brakes are repaired.

WHEEL OFF THE ROAD:
On any roadway, you may find yourself with your right wheels off the pavement and on a soft or low shoulder. This seemingly harmless situation has been the
immediate cause of countless automobile accidents.

Don’t jerk the car back onto the pavement! This all too frequent, nearly instinctivereaction is deadly. You stand an excellent chance of coming back onto the hard
surface sideways and going into a spin or tipping the vehicle and rolling over.

Don’t jam on the brakes! Instead, ease off the accelerator pedal. Keep a firm grip on the wheel and straddle the edge of the road as the car slows down. When
your speed is reduced considerably, use the brakes lightly to further control your speed. Then, and only then, get back onto the road after checking to be sure
traffic will permit you to do so.

STUCK GAS PEDAL:
Suppose you are traveling on a busy highway, and have accelerated to pass another vehicle. You complete the pass and ease up on the gas pedal as you
swing back into the proper lane. But the gas pedal does not return. You are picking up more and more speed, and your repeated kicks and stomps on the
pedal have no apparent effect. What do you do?

Well, obviously, you will apply your brakes, but equally important, do turn off the ignition and if possible, get into a lower gear. The drag of the engine will aid in
slowing you down, and you can safely leave the road.

EMERGENCY STOP IN TRAFFIC:
Good drivers, such as we are, never follow too close in traffic. But all drivers, unfortunately, are not so good as we. Let’s assume you are driving a comfortable
ten car lengths behind another automobile and 60 mph on a two-lane highway. Another car is following you at an uncomfortable two car lengths distance. As
you start to move up and get away from the “bumper hugger” behind you. a third vehicle passes you both and pulls in ahead of you. Just as he gets in ahead
of you and starts accelerating away from you, something happens ahead of him and his brake lights flash as he brakes hard, losing speed rapidly.

At this time, hand signal and feather your brake pedal rapidly to warn the car behind you. Then, apply the brakes as hard as is practical. Remember, however,
that if you decelerate too rapidly, the car behind you may plow into you.

Choose an escape route to the right, since at some point during the brief seconds in which the situation is developing, you may have to make a decision to leave
the road. You will probably not want to trypassing to the left since this will expose you to a possible head-on collision, and it would probably be preferable to bump
the back of the vehicle ahead of you. Here again, however, you must consider the car behind you since the prospect of being sandwiched in between two vehicles is
not a particularly happy one. There is a risk of going off the, right shoulder, too, of course, but it may be the only alternative left to you.

If you do leave the road, remember:
1. Get both right wheels off at the same time if possible.
2. Keep a firm grip on the steering wheel.
3. Once you have committed yourself to leaving the road, use the brakes only if you have to during the high speed portion of the maneuver. Remember, sliding
front wheels will not steer.
4. When your speed has been reduced, use brakes to complete bringing your car under control, and return to the road when it is safe to do so.

G. TECHNIQUES

UPSHIFTING:
Most drivers forget that they’ll only go thru the gears once in a race. This happens at the start when everything seems to be at the maximum. From then
on it’s playing up and down with the intermediate gears. However, a few general comments are necessary to help you achieve the best acceleration.

If you take it to the red line each time, you are probably not getting the maximum acceleration from the gear train. Probably, the only thing you have accomplished
is to develop maximum horsepower in each gear. However, you have forgotten about torque or pulling power, which is usually achieved below maximum power
and maximum revs. A good rule of thumb is that maximum torque is about 40% of the maximum speed. Furthermore, once maximum torque is achieved, horsepower
increases less rapidly.

While acceleration is dependent upon torque, weight, adhesion and gearing, for simplicity just watch your tach. For maximum speed thru the gears, shift at the
torque peak, spool, the engine up to peak power, shifting to the next upper gear. The critical factor is the speed with-in the gear shift itself. For maximum
acceleration you don’t want the revs to drop below the torque peak.

If you reach peak power while the car is still accelerating, you need a higher gear. On the contrary. If you can’t get the engine up to peak power in high, you’ve run
out of power and need a lower gear. The worse condition is for underpowered cars where you are still accelerating AND climbing toward peak power and you run out
of road. The only solution is more torque or a longer course!

For the exact figures of peak torque and horsepower, check your owners manual or the tech specs with the sales literature. In addition, a comparison of the torque/
power curve itself is usually very helpful.

DOWNSHIFTING:
The most popular method with a synchro-mesh transmission is to blip the gas, depress the clutch, and move the shift to a lower gear.

The second method is called DOUBLE CLUTCHING. In this method the clutch is depressed, the gear moved to neutral, the foot removed from the clutch while
simultaneously using the accelerator. The clutch is then depressed again and the gear lever moved to the desired gear. This method is used with old-fashioned
gearboxes, or when the gears are difficult to change. Since there is less chance of inducing wheelspin, and the transmission and gearbox suffer less strain, if your
gearbox is acting-up, try this method to save the box and yet continue the session.

The main purpose of downshifting is to effect engine braking as well as selecting the proper gear for exiting a corner. However, it is important to know what revs
to change at for the maximum benefit. Here is a simple example: Engine has a max/safe rev limit-5000 rpm.

Gearbox ratios:
FOURTH GEAR -1.0:1
THIRD GEAR-1.2:1
SECOND GEAR-1.5:1
FIRST GEAR-2.1:1

The drop in revs are easy to spot when upshifting with a tach, but can also be predicted. In our example, assume you are at 5000 rpm in third and then shift to
fourth, the tach will drop to 4170 rpm. Likewise, the tach will swing from 5000 rpm to 4000 rpm when shifting from second to third, etc.

This can be mathematically shown by multiplying the max revs by the ratio of the gears: 5000 x 1.0/1.2 = 4170 rpm; 5000 x 1.2/1.5 = 4000 rpm. This is most
important when down-shifting to avoid damage to the engine. If you are at 5000 rpm in third gear and downshift to second gear, the tach will scream up to
6250 rpm – over the safe limit. Therefore, to be sure that you do not overrev in a downshift, the engine must be down to 4000 rpm In third gear before attempting
a downshift. In this example, second gear would be engaged at 5000 rpm or max revs. and allowed to drop substantially during the braking phase prior to reaching
the corner. This knowledge and successful application provides engine braking as well as positioning you in the proper gear for powering out of the corner and
upshifting. Naturally some corners will require two or more downshifts before
entering.

CORNERING:
This is the essence of driving a sports car and can be broken down into various elements. These are BRAKING, POWER-ON, THE CORNER, OUT THE CORNER. The
most important factor is to brake, downshift and accelerate BEFORE the corner.

Don’t take the corner in neutral or just coast thru it. For proper control, power must be maintained thru the corner.

We will show the simplest methods of cornering. Master these concepts and move to the examples where two corners are completely dissected. Finally, each corner
at Waterford Hills is analyzed in detail.

Remember how you manage the forthcoming corner will set you up for the next corner in a positive or negative manner. Smoothness and consistency are the
important factors.

POSITION OF THE HANDS ON THE STEERING WHEEL DURING THE ACT OF TAKING A 90° CORNER TO THE FRONT
Graphics (coming soon)



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