Paul Brand: Think of a skid as a pendulum to time steering

Q About the writer who had trouble with rear-end breakaway and corrective steering: first, praise to the driver because his steering-wheel correction was in the right direction. Many people steer the wrong way!

However, the result he describes -- first left, then right, then left again -- comes from overcorrection. In engineering terms, the motion was underdamped. This is understandable in the panic of a skid, when there is a tendency to overdo the reaction. In this case, however, more is not better.

The best solution is experience and practice because you get a feel for how much to correct, and because it makes it all more comfortable (less adrenaline). After about 50 skids you get a feel and can halt the breakaway on the first correction.

However, lacking electronic stability control, there is some benefit from hand positioning. Holding the wheel at 9-3 and correcting without moving your hands help to limit the overreaction. "Slapping" the wheel or putting in big turns is a problem. Not only does it induce an opposite swing of the rear, you risk the front end breaking away as well. Then you will skid into the wall.

It's surprising how little actual correction of the wheel is optimal -- a 90-degree wheel turn is often too much. Even less when the breakaway is in a turn because some rotation of the car is needed to go around the sharp bend, often 270 degrees in a cloverleaf.

There are a number of driving schools that offer training driving around cones in a "sudsy parking lot."

A Thanks for your thoughtful comments and for creating another opportunity for me to expound upon this phenomenon. While I agree with many of your points -- the need for practice and experience, for example -- my 20-plus years of teaching racing, high-performance and law-enforcement driving have given me a special perspective on this issue.

First, "overcorrection" is inaccurate. The "yaw" is generated by the rear tires sliding while the front tires are still gripping the pavement. The vehicle is effectively a pendulum pivoting around a vertical axis through the center of the front axle. There are only two key issues to saving a slide like this -- steer the same direction as the back end is sliding (just as you noted), and make the steering correction right now!

You're correct in noting "how little actual correction of the wheel is optimal," but only if the steering is corrected virtually instantly. The key to this is the eyes -- look where you need the car to go, not where it's going. Because the hands naturally follow the eyes, by looking in the direction the car is sliding, the hands tend to make the right correction.

Sadly, inattention, distraction, lack of understanding, inexperience and panic tend to delay the driver's recognition, processing and response to the slide. This allows the slide to increase in angle, meaning the front tires are no longer pointed where the car is headed, and once the correction is begun, more steering input is necessary.

Now, if the steering correction is properly dialed in, the pendulum effect begins to slow. If there's enough traction available from the pavement, the rear tires finally stop sliding, and the vehicle is at the limit of the yaw/slide and ready to snap back in the opposite direction. In performance driving vernacular, the energy built up in the rear springs unloads as the tires regain grip, initiating the "second reaction" hook slide. This occurs because the driver does not recognize the pause of the pendulum and the impending second reaction, and the back end snaps back in the opposite direction while the steering is still corrected in the direction of the initial slide. The instant the rear of the vehicle begins to swing back in the opposite direction, the front tires are no longer pointed where the vehicle needs to go -- thus the start of the back-and-forth "fishtailing," or, in the racing world, "death wiggle."

To prevent this, the three steps necessary to save a rear-end slide are correct, pause, recover -- or C-P-R in the motoring world. Steer into the slide just enough instantly, anticipate the pause as the back end rotation begins to slow, and continue to look where you need the vehicle to go. Prepare to steer back in the other direction at the same moment the back end begins to snap back. Timed correctly, C-P-R keeps the vehicle traveling in the same direction it originally was before the back-end sliding.

Thus, there's really no "overcorrecting." It's more of a delay in initial steering input, then a delay or lack of recovery -- turning the steering back toward the center/neutral position as the back end snaps back. It gives the appearance of overcorrecting because the front wheels, as the car snaps back, are still turned in the original direction of the skid. But it's because of the delay in recognizing and responding to the second reaction, not because the wheel was turned too much initially.

One final key point. In terms of how much steering correction to input, this is entirely dependent upon two things: How quickly the correction occurs (as you noted above), and how rapidly the pendulum or back end is rotating around. There are wimpy little slides on dry pavement that require only small corrections, but then there is the "mother of all slides" at higher speeds or on wet pavement that requires every bit of available steering wheel input/angle to keep the front wheels pointed where the vehicle is sliding. This is why the "shuffle steering" technique is so important. It doesn't matter how quickly the steering correction is done -- if the steering isn't turned far enough to keep the front wheels pointed where the vehicle is sliding, the back end is never going to pause, giving the driver a chance to recover.

As a side bar, a "sudsy" parking lot isn't an effective teaching tool for the simple reason that an artificial super-slippery surface never allows the rear tires to regain grip, slowing and stopping the pendulum. Thus, there's little or no potential for the second reaction, and students do not learn this incredibly important piece of information. This is why it's so much more difficult to "save" a slide on ice.

The last words on this issue: What if you don't "catch" the slide? In racing terms, "if you spin, both feet in," meaning lock the brakes hard instantly and keep them locked until the vehicle comes to a complete stop, and if it's a manual transmission, push the clutch in to keep the engine running. This slows the vehicle as rapidly as possible and keeps the vehicle traveling in a straight line, hopefully right down the middle of the road, as it spins.