Virtually all of the braking that a race car driver does is done in preparation for or in conjunction with cornering. One of the first lessons that every racer must learn is that the most efficient way to slow a car is in a straight line, with the car's weight evenly distributed side-to-side. The "standard" turn on a race course is made under power, with all slowing having been done before the car is turned.

In the last article I noted that braking transfers weight from the rear of the car to the front, and that your braking system is designed to accommodate this. Cornering transfers weight from one side of the car to the other -- from the inside to the outside of the cornering direction. The braking system is not, with rare exceptions, designed to adapt to this weight transfer. The driver has to adapt instead.

Any time we turn our car's steering wheel we compromise braking efficiency. When we turn left, for example, some of the car's weight transfers to the right side; the left side of the car gets lighter. If we brake (or, for that matter, even slow down) at the same time, the car's weight is transferred forward as well. Now the car is unbalanced; the braking and tire adhesion forces on all four corners of the car are different. In all likelihood, each of the four wheels is either bearing too much weight to brake efficiently or too little weight to stick to the pavement optimally.

At the very least this condition will make the car uncomfortable for its passengers and difficult to steer. At the worst, it can cause the driver to lose control of the car entirely. The solution? For comfort or for safety, whenever possible, don't brake and turn your car at the same time. If you have to do so, be aware that it will neither brake nor turn as well as it would if you were doing one at a time.

While absolutely correct braking and cornering may not be a matter of safety at street driving speeds, they can be a matter of increased comfort. Next time you drive on the street try slowing down for corners before you turn the steering wheel to negotiate them. Turn at a constant (but not too fast) speed, and as you start out of the turn, accelerate gently. If that's different from the way you usually drive, you'll feel the difference immediately and so will your passengers.

The same braking technique will make driving a curvy road much easier: concentrate on slowing down for each corner while the steering wheel is straight. If the corners are esses, slow during that brief time when the wheels are straight as you turn from one direction to the other. Do this as smoothly as possible. Accelerate lightly coming out of the corner. Assuming you've judged your cornering speed correctly, slowing in a straight line and not braking while turning will make a dramatic difference in the ease and comfort with which your car negotiates a curvy road. And it will let you make better time without having to drive any harder.

Ideally all braking should be done before the wheel is turned for a corner. At the very least, 70% of your car's braking should be done before turning, and all of it should be completed by one-quarter of the way into the turn.

The cornering/braking tradeoff is dramatically illustrated in a highway emergency situation we've all seen or experienced. The car in front of you stops abruptly. You brake as hard as possible and swerve into the breakdown lane simultaneously. If you're lucky, this works, but it's only because you weren't stopping as quickly as you could have. If you're less lucky, you're suddenly sliding sideways toward the car you'd hoped to avoid or you're in a spin.

That shouldn't be a surprise now that you know your car can't brake and turn optimally at the same time. If you've mastered the technique of "instantly" squeezing your brakes to the limit, you'll brake at the limit first, then ease off your braking slightly to turn to the side; or, if getting out of the lane is more critical, brake lightly to preserve turning capability.

Copyright © 1998 by Tim Moser of Silhouette Racing. All rights reserved.