Often overlooked as a handling factor, the driver is actually one of the biggest factors affecting handling balance. The driver influences weight transfer by how and when the controls are utilized. When the driver uses the brakes, applies the throttle or turns the steering wheel, weight transfer begins to occur, and how quickly the driver uses those controls affects how quickly weight transfer happens. So the driver controls when weight transfer begins and affects how fast it takes place. And weight transfer affects traction and roll couple distribution or handling balance. So, how well the driver manipulates the controls determines how well the driver is managing tire traction.
Small changes in steering wheel angle and how fast the driver rotates the wheel, how hard and quickly the brake pedal is applied and how smoothly power is applied can make a big difference is handling balance, lap times and, over the course of a race or run, how well tires are managed. Smooth, consistent motions relative to control use will have a very different effect on the platform balance and tire traction compared to rapid and abrupt control inputs.
HANDLING AILMENTS: CAR OR DRIVER?
Driver error should always be considered when handling problems crop up. There are several items to consider when analyzing handling problems. The first consideration is to confirm or eliminate the driver as a possible cause. This is important because, no matter how good a driver is, the car will always be more consistent. Keep in mind, the driver influences weight transfer and tire traction at each corner of the car in a variety of situations. If the driver is too hard on the throttle, he can cause either a push or a loose condition, depending on what he does with the throttle pedal and when. How and when the driver uses any of the controls will often cause or cure a perceived handling problem.
HOW A DRIVER CAN CAUSE A HANDLING PROBLEM ENTERING A TURN
If the driver comes into the corner too hot under hard braking, and attempts to rotate the car while applying too much brake-pedal pressure, then a significant push is created. Ironically, it also can cause the car to get loose. If the car has too much brake bias to the rear, a loose situation can result under heavy braking while steering. Too much front bias and the situation reverses. A slight roll-couple bias can have the same effect. Too much front roll-couple causes a push, too much rear will create a loose situation.
The overriding factor here is the driver. If the driver brakes too hard and tries to rotate the car — more steering wheel lock applied while braking — the car will have a handling problem just like the one I just described. The situation may not appear until the tires get hot. This will typically cause the car to push since the front tires may be overheating due to heavy braking going into the corners. The situation will only get worse as the tires get hotter and begin to wear.
Even if a car is perfectly neutral, the driver can cause a handling problem by making the steering motion too quickly or abruptly. Jerking the steering wheel can cause the front tire slip angles to increase suddenly relative to the rear tire slip angles, causing a push to begin, which can linger even though the rear tire slip angles eventually catch up to the front slip angles.
HOW A DRIVER CAN CAUSE A HANDLING PROBLEM WHILE EXITING A TURN
Corner exit handling problems also can be driver-caused. The most common situation is wheel-spin exiting a turn. This is almost always caused by the driver slamming the throttle pedal too quickly. More cross weight may reduce this on an oval, but on a road course, it’s the driver who has considerable influence over the situation. Just like the entry of a turn, the same action by the driver could cause the exact opposite problem. A push at the exit of the turn can also be driver-induced simply by accelerating too hard with too much steering lock. If the relative amount of drive torque available is too little to cause wheel-spin, the weight transfer due to acceleration can increase rear tire traction while reducing front tire traction. This change in balance often causes a push at the exit of a turn when wheel spin is not likely to occur. In each case, the driver is misusing the controls, which upsets the handling balance.
HOW TO CURE DRIVER-INDUCED HANDLING PROBLEMS
The first step in curing driver-induced handling ills is to recognize that the driver may be the cause of the problem. This can be difficult for two reasons. First, handling problems can be easily masked since several different scenarios can be the cause for a given problem. Second, it can be difficult for drivers to have the insight and honesty needed to look within themselves for the problem. It takes courage and commitment to confront yourself and your ego to seek the truth. There are several clues to help determine whether the car or the driver is the root of the problem.
- If the problem is inconsistent, it is most likely driver-induced.
- If a problem occurs at every similar type of turn, it is most likely, but not always, setup related.
- On road courses, if a problem occurs on either left or right turns only, it is likely setup related.
- If the problem occurs at one turn only or one segment of a turn, it is likely driver-induced.
IMPROVING YOUR DRIVING TECHNIQUE
Driver control errors cause handling problems. These errors fall into two categories, all occurring during transitions. First is abrupt control responses. Jerking the steering wheel, hitting the brake pedal too hard, or nailing the throttle to the floor too quickly are the usual problems. Second, the timing of control use may be off. Turning the steering wheel too soon or too late going into a turn can upset the car, causing problems. The same applies to the brake and throttle pedals. Smooth movements of the controls timed perfectly will eliminate most of the driver-induced handling problems.
Here are some examples. Turning the steering wheel too quickly at the entry to a turn can cause a push or loose condition. This relates closely to the use of the brakes in unison with steering. If the steering wheel is turned too quickly while the brakes are applied too much going into a turn, the front tires will be overloaded. The tires can steer and decelerate the car at the same time, but only up to point. The combination of brake and steering cannot exceed the limits of total tire traction. The tires create only so much traction regardless of direction — accelerate or brake, plus turn. The combination can go right to the traction limit, but not exceed it. All of the traction can be used to turn, or to brake, or some combination of the two. If the limit is exceeded, the tires will slide, usually at one end of the car before the other.
The driver is in complete control of this. More steering means less brake. More brake means less steering. If you need to turn the wheel while braking at the limits of tire traction, the tires cannot do the job. If all the traction is needed for turning, then no braking can be used, and vice versa.
The same situation applies to the corner exit. More traction for acceleration requires less steering lock by the driver. Maximum traction efficiency requires you to stay on the limit of the traction circle. If you go over the limit of the traction circle by asking the tires to do more work than they can, a handling problem will occur.
Think of the throttle and brake pedals as being linked to the steering wheel. More pressure on the pedal means less steering lock. More steering lock means less pressure on the pedals. Too much steering or too much pedal pressure causes tire traction limits to be exceeded.
As you enter a turn under braking, you must ease off the brake pedal to stay within the limits of traction. At some point in the turn, all the traction must be used for cornering, so the brakes are released and the car balanced with the throttle without acceleration. At the exit of a turn, to facilitate acceleration down the straights, the steering wheel must be unwound. If it is not, a handling problem, caused by the driver, will occur. The big question is finding the balance between pedal application and steering wheel lock angle. Too much of either will cause the fine balance to be lost and the car will fall off the desired path. Too little will be slow. Learning to keep the car balanced on the edge of traction is the key to being a fast race driver.
Finally, timing of control use is crucial for fast driving. Turning in too early can require using more steering lock midway into a turn. This should require a reduction in braking force, but then you may enter the corner with too much speed. This circumstance may also alter your line around the corner. Braking too late, turning in too late, not rotating the car at the best place on the track can force you to slow the car to avert disaster. Timing can be thrown off if control movements are too slow. The combination of smooth control use, perfect balance between pedal and steering inputs, and precise timing make driving a racecar an art form. Being off by 5 degrees of steering wheel angle, 10 pounds on brake pedal pressure, or a tenth of a second on timing can cost valuable hundredths of a second on the racetrack. True speed is found by perfecting your skills in these areas.
BASIC CORNERING THEORY FOR THE TRACK
Entire books exist covering this topic, but here are five basic principles to get you going in the right direction. While it is crucial to drive the corners as close to limits as possible, the real goal — and the fastest way — is to find the best compromises allowing you to accelerate, preferably at full throttle, the maximum amount of time during a lap. While braking and steering are an absolute necessity, both actually slow the car, so spending the least amount of time steering and braking and the most time accelerating is the key to fast lap times.
1. TURN THE STEERING AS LITTLE AS POSSIBLE WHILE CORNERING
The act of steering scrubs off speed. For this reason, spend as little time as possible steering. And turn the steering wheel as little as possible to get through a corner. This is an “area under the curve” exercise. If you plot on a graph the steering angle of the steering wheel versus the time spent turning the steering wheel, the driver with the least area under the curve is the fastest. This requires scribing the largest arc possible through a corner. A line starting from the outside edge of the track, apexing at the geometric center of the corner on the inside of the track and exiting to the outside edge of the track will accomplish this as long as the arc is smooth. Steering corrections, while necessary at times, add to the area under the curve and cost time.
2. ALTER YOUR LINE IF YOU ENCOUNTER CORNER-EXIT WHEEL-SPIN
The goal is get back on full power as early as possible exiting a corner. Some corners are flat out, allowing full throttle throughout, but most corners require braking to negotiate the turn. Getting back on full power as quickly is possible is the key to fast laps. If full-throttle application induces wheel-spin, alter your line so that you can unwind the steering earlier in the exit phase of the corner, This allows the tires to use more traction capacity for acceleration. This line requires a later turn-in — meaning more steering angle — a later apex, but an earlier throttle application to full power and maximum acceleration.
3. USE LIMIT BRAKING WITH CAUTION
Braking at the limits of tire traction, also called threshold braking, is important for fast lap times, but it can cause problems at corner turn-in. Keep the traction circle theory in mind. As you reach the turn-in point, ease off the brakes as you begin to steer. More steering means less braking. You should be braking for a slow corner about one-third of the way into the turn for maximum tire traction utilization. But you must find the find balance between steering and braking to take advantage of the tire’s maximum traction. Too much steering for the amount of braking will cause a handling problem, scrubbing off speed and overheating the tires at the minimum, or resulting in an off track excursion — or a crash — at worst.
4.CONTROL USE: SMOOTH VS. ABRUPT
Smoothness counts. Abrupt use of the controls can initiate handling problems, overheat tires and accelerate wear. It is almost always slower. There are rare cases where abrupt control inputs can be used to coax the car into a desired behavior, but if such a tactic works, then the car setup needs to be addressed. Long-term abrupt control use destroys tires quickly and costs time in any event lasting longer than a single lap.
Abrupt steering input can cause tire slip angles to increase too quickly, overloading the tires, and can cause the slip angles to be higher than necessary, causing scrub, heat buildup and accelerated wear. Too abrupt on the throttle can cause wheel-spin. And an abrupt application of the brakes can cause wheel lock up and force forward weight transfer to take place too quickly, overloading the front tires at the turn-in to a corner.
So what is smooth? That’s tough to define! The best advice is to try using the controls more slowly. You may not be able to tell when you are using the controls too quickly, but you will know when you are using them too slowly. Slow down control movements until they feel too slow.
5.WHEN YOU DRIVE, WHERE YOU LOOK IS WHERE YOU GO
By looking farther down the track, you relax and things are happen more slowly. The driving is more fun and is actually much safer. And now you start to go faster than ever without added stress.
Where you look determines nearly every aspect of your driving: speed, comfort, style and safety. But is important to use your eyes effectively to become a better driver and to go faster as well. Visual fields are one of the most important areas of attention for any driver, but especially for the competition driver. What you see determines how you implement and modify your game plan. If you fail to see something important, it can cause problems. Knowing where to look, and what to look for is crucial for success, as well as safety, in all forms driving.
Visual fields are simply where you look and what the eyes are taking in. Most of the data you gather for decision-making in a racecar is taken in visually. Your visual field could be the dashboard, down the road 300 yards, into a corner, a billboard, or anywhere you look. A short visual field limits data gathering, while a long visual field promotes greater data intake. The data you gather is needed to make decisions. “Where do I apply the brakes? When do I turn the steering wheel, and how much? What are the other cars doing?” Each of these questions, and dozens of others are answered by visual data you take in while on the track. If the visual data you take in is faulty, inaccurate or incomplete, the result will be lost time on the track and greater risk on the highway. You’ll either be too slow or too scared.
Your focal point determines what your visual field encompasses. Try this exercise right now. Focus on the page you are now reading. Don’t change your focal point, but notice what is in your peripheral visual field. What you see is limited, so the data you can gather from your visual field is limited. Now focus on an object several feet away. Do the same thing with your peripheral vision. You can take in more data. Try this on objects even farther away. As your focal point moves out away from you, your ability to gather important data improves. Within reason, the longer your focal point, the larger your visual field and the more data you can take in with your eyes. What you focus your eyes on is very important.
THE CRYSTAL BALL
Your visual field is like a crystal ball. It allows you to take a look into the future. For example, at 130 MPH, you are traveling at about 200 feet per second. If you look 200 feet ahead, you have a one second look at what will occur in 200 feet. But if you look at the bumper of the car just ahead, you have only 1/10 second look into the future.
During the time you give yourself with your visual field, three important factors occur. First, that is the time you have to implement your plan. Second, it is the time you have to plan tactics based on the cars around you. Third, it is the most amount of time you have to take evasive action in an emergency. You may have less time if the situation occurs within your visual field closer to you. Let’s look at these more closely.
Whether you realize it or not, you have a plan for getting around a racetrack or down the highway. You must “plan” when you will turn the steering wheel, when to brake and when to use the throttle. Your visual field determines how far your plan reaches and how much time you have to implement the plan. If your visual field encompasses 100 feet in front of you, your plan for using the controls to position the car and control its speed extends 100 feet, and the time you have to implement the plan is determined by the speed of the vehicle.
YOUR PLAN ENDS WHERE YOUR VISUAL FIELD ENDS
To get through a corner effectively, you need a plan to get you completely through a corner. And that requires a visual field that stretches through the corner. A big visual field will allow you to see the path you want to drive and make smooth transitions on and off the controls. A short visual field, even if it shifts, does not allow you to see the big view, so you are forced to make several smaller plans, leaving little time to implement the plan and requiring you to react to rather than anticipate situations. This forces more abrupt transitions, and can cause you to lose speed.
Your visual field will affect your ability to create and implement tactics. The more you are forced to react to situations, the greater your disadvantage becomes. Larger visual fields allow you to anticipate tactical situations earlier in the majority of situations. If you count on reacting to situations, you will lose just about every time. If you give yourself time to anticipate the situation, whether you are attacking or defending, you will have a higher likelihood of success.
WHAT TO LOOK AT
Visual fields should always be dynamic, that is, always moving and changing. It is ineffective to focus on a marker or object 300 feet down the road, and maintain focus on that object until you pass. The effective way to use visual fields is to constantly change them. Keep your eyes moving. For example, as you approach a corner, your eyes may sweep through the braking zone, and then through the corner to the exit before moving back to your braking point and the path you plan to drive at the entry to the turn. During this time, you may also glance at the mirror or use your peripheral vision to check on the position of other cars.
At different times, the visual priorities will change depending on the position on the track, the situation in a race and other circumstances. It is best if you have an idea of where you need to shift your visual field at various points around the racetrack, or in various situations.
All race tracks and all roads have reference points of some type. These points can be anything: marks on the racetrack, cracks, marks on the walls, poles, etc. Use reference points to help you create and maintain your plan. Be sure to use permanent markers, not ones that can move.
As you approach the braking area, you should look all the way through the braking zone into the corner so that your plan is as complete as possible. Then shift your visual focus to the braking point, and allow your eyes to follow your desired path through the braking zone. As the brakes are applied, your visual field should shift to the corner, so that you have a clear mental picture of your desired path into and through the corner.
GOING INTO A CORNER
As you go into the corner, you should have already looked completely through the turn, and then you can shorten your visual field for specific reference points. Once into the corner, your visual field should move to the exit.
EXITING A CORNER
You must see out of the corner as early as possible so that you can unwind the steering and feed in throttle to maximize acceleration. This is probably the most important phase of the corner, and your visual focus is important. It is best to extend your visual field out of the corner as early as possible. Once your path is determined on the exit, you can check the mirrors or gauges as you enter the straight.
In many cases, especially on road courses, you will encounter physical obstacles that impair your vision, or create a blind cornering situation. In these cases, you need to have experience well below the limits of traction through those areas to drive them effectively. With experience, you will be able to get up to the limit. This process allows you to see “through” the blind spot as if it were not there. You are actually fooling your mind into believing that you actually see through the blind area. The risk is higher, since you cannot see developing trouble, and you cannot plan tactics in such an area, but you can drive to the limits using this technique. The key is to practice at low speed, gradually build speed as confidence and experience increase, then start to approach the corner near or at the limits.
Most of the data you accumulate is visual. A larger visual field will allow you to take in more information, and give you more time to process it. Short visual fields limit data, and cause the driver to react instead of anticipate. Anticipation of control usage allows you to drive more smoothly and precisely. To become a proficient driver, you should work on making the best use of your visual field. Keep it long and moving. This will buy you time, improve your performance and make all forms of driving safer.
As you can see, the driver plays a crucial role in handling as well as overall success in competition. The driver should be the easiest element on a car to adjust, but drivers are rarely that easy to tune. Egos are hard to read and work with. For that reason most skilled drivers leave their egos behind.