Last month we introduced you to the world of autocrossing and told you what was involved. Now were going to tell you how to win.
Many say consistency is the key to being a good racer, but consistency means nothing if your technique is wrong to begin with. Fortunately, technique is something that can be learned, so if you get out on the autocross course and run the slowest time, dont give up.
Instead, learn from your mistakes and alter your driving style.
Being smooth at the controls is the key to running fast. In order to be smooth, you must have the correct seating position, foot position, steering wheel grip, and a good mental map of the line youre planning on running through the cones. Each of these items must be understood and perfected before you will be able to run fast, consistent lap times. Fortunately, seating and foot positioning will be the same on all autocross courses, so once you have perfected those, all youll need to worry about is running the correct line.
In The Cockpit
Before you can improve your driving techniques, however, you must be seated correctly and know how to brake efficiently. One of the most common errors beginners make is driving like actors on television. Rather than reclining the chair and grabbing the top of the wheel with the left hand and placing the right hand firmly on the shifter, the correct racing position is to be seated fairly close to the steering wheel with your hand on the shifter only while shifting.
Seat yourself close to the steering wheel, so you can turn the wheel either direction without fully extending your arms (But not too close, so your arms shouldnt hit your body during tight turns.MAX). Your hands should be positioned loosely at each side of the wheel, in the nine oclock and three oclock positions. Do not clench the wheel, as your hands and arms will become fatigued. When you shift, dont grab the shifter or slam it into gear.
Instead, use the palm of your hand or your fingertips to smoothly slide the gear lever into the next gear, returning your hand back to the steering wheel when the shift is complete.
Heel-and-toe braking is difficult, but fortunately, there are few shifts on an autocross course, making this almost a moot point. But as the gains of heel-and-toe braking are tremendous both on and off the track, we believe everyone should at least practice. Heel-and-toe braking is when the driver manipulates the throttle and the brake at the same time with the right foot. The idea is that when entering a turn and downshifting at the same time, the engine revs must be matched or else the driving wheels will lock up and lose traction. Heel-and-toe braking allows the driver to brake, shift, and set up for the turn, all without the worry of locking up the tires or offsetting the vehicles balance.
There is no established method of positioning the right foot for heel- and-toe braking, but the most common method is placing the toes on the brake and rocking the right side of the foot onto the throttle (Heel-and-toe braking is misleading, as most people dont use their heel on the brake or the throttle.MAX). While the brake is being applied, the clutch is depressed and the vehicle is downshifted. At the same time, the throttle is pressed for an instant to raise the engine revs, and at that point the clutch is released. With practice, the downshift will be seamless and the vehicles weight distribution will not be offset during the shift. If too little throttle is applied, the nose of the vehicle will dive once the clutch is released, causing an oversteer situationor, in the case of the front wheels locking, an understeer situation. If too much throttle is applied, the vehicle will accelerate towards the turn, causing the entrance of the turn to be missed.
With practice heel-and-toe braking can be the most efficient way to downshift while reducing speed. It may feel uncomfortable at first, but rest assured that any person who can drive a manual transmission car is capable of heel-and-toe brakingall it takes is practice. The best place to learn heel-and-toe braking is on the streets.
Every time you downshift under braking, practice rolling your foot onto the throttle at the same time. Once you get good, you can even heel-and-toe hill starts.
The line is not the shortest way around the trackits the fastest. If you drive the shortest line around the track, youll find yourself running on the inside of each turn, which is generally the harshest and slowest part of the turn. The idea behind the line is to transform a turn into a straight line, or the closest thing possible, thus allowing for the maximum amount of time accelerating around the track. There are, however, several lines that can be run throughout the same turn.
Figure A shows two distinct lines for the same constant-radius turn. The solid line shows the geometric line around the turn, while the broken line shows a late-apex turn. Following the geometric line, (A) marks the entrance point, (C) marks the apex, and (E) marks the exit of the turn. Since this line uses a constant turning force around the entire turn, the speed the vehicle travels though the entire turn (From point (A) to point (C) to point (E).MAX) is the same. If the speed is exceeded, the tires will lose traction, and the car will slide off the line.
The late-apex line is a different approach to taking a turn. Point (B) denotes the turn in point, (D) marks the apex (Which is later in the turn than the geometric line, hence the name late-apex turn.MAX), and (F) marks the exit. In this case, however, once the apex is reached, the turn of the wheel is significantly reduced, thus the car can begin accelerating sooner without the fear of sliding off the line. Which line is better? Both have their perks, but for people who are racing vehicles driven daily, the late-apex line is usually the best. The reason is that street-driven vehicles can brake much faster than they can accelerate, so braking time must be minimized and acceleration time must be maximized. Although the entrance to the late-apex line is slower than the geometric line (Because the initial turn in is harsher.MAX), by the time the apex is reached on the late-apex line, the vehicle can begin accelerating, thus maximizing the amount of time on the throttle. In this case, at point (C) the vehicle running the geometric line is traveling faster, but point (D) marks where the late-apexing vehicle can begin to increase the throttle, whereas the geometric-apexing vehicle must wait until point (E). By the time both vehicles reach point (F), the vehicle that took the late-apex will be traveling significantly faster than the other vehicle, and that speed will be carried to the next turn.
In order to trick people, most autocross courses consist of different kinds of turnspossibly the trickiest is the decreasing-radius turn. The decreasing-radius turn is a turn that starts out as a constant-radius turn, but as the turn progresses, the severity of the angle increases. If youre not careful, this kind of turn will lead to braking during the exit of the turn, a maneuver which should only be done in emergencies. Luckily, decreasing-radius turns are not that difficult to master. Looking at Figure (B), youll see what a decreasing-radius turn looks like. The line that should be run through the turn is simply an arc that is the same intensity from the turn in, point (A), until the apex, point (B). This line is also a late-apex in order to maximize acceleration. Late-apex turns are tricky (Especially with decreasing-radius turns.MAX), but mastering these will separate you from the beginners.
Turning is not accomplished completely through steering inputs. Throttle steer is when you change the direction of a vehicle in a turn through the use of the throttle instead of the steering wheel. Throttle steer is a great technique for keeping a vehicle on the correct line, without upsetting the vehicles stability as much as a steering input. But before you can begin throttle steering, you must enter the turn at nearly the correct speed. The correct speed is the speed just before the front wheels plow through the turn, due to too much speed carried from the straightaway. Until you become an experienced driver, try to have all your braking completed before you enter the turn.
If, when youre in mid-turn, you realize your vehicle is too close to the inside of the turn, increasing the throttle slightly will move the weight off the front tires and push the car to the outside of the turn. Conversely, if the vehicle is outside of the line, releasing the throttle a little will force more weight onto the front tires, and the vehicle will steer closer to the center of the turn. Be careful, however, as too much throttle change could cause the vehicle to spin or slide off the track. Throttle steering inputs are slight and should never be abrupt. Remember, be smooth with all the controls.
Two throttle steering characteristics are throttle oversteer and throttle understeer. Throttle oversteer occurs in rear-wheel-drive cars when the rear tires accelerate beyond the point of traction during a turn, causing the rear end to slide out. Conversely, front-wheel-drive vehicles undergo throttle understeer, when the front tires accelerate beyond the point of traction during a turn, and the front end of the vehicle slides toward the outside of the turn. Because of these handling characteristics, you should be careful (And prepared.MAX) when using the throttle to steer.
Dont expect to get onto an autocross course and win the first time out. Winning requires mastering all aspects of driving through practicelots of it.
After awhile, however, this will become second nature. Before you know it youll find yourself heel-and-toe braking into decreasing-radius turns on your drive home every day. But as much as weve covered, there is still plenty more to discuss (Like trail braking, slip angles, wet lines, transitory turns, and road camber, to name a few.MAX), so we recommend talking to as many racers as possible to hear their strategies and autocrossing as often as you can. The best advice we can give is to have fun and enjoy the ride.