Mental/Physical Preparation Before A Run

Stuart R. submitted a comment that he claps his hands together before each run to increase his tactile sensitivity. I replied that this was great and that I also have a routine I do before each run. It just takes a few seconds once you learn it. Feel free to throw in some hand clapping!

This may seem a little silly. That’s OK. It’s just what I do based upon what I’ve learned in the various athletic-type competitions, namely wrestling and internal and external martial arts throughout my life, as applied to autocross driving competition. I suggest you try it and then modify to suit.

Of course, this kind of thing (not this procedure in particular) applies equally to any important human performance. An example might be a business or technical presentation. I gave literally hundreds of those during my career. I’m off-the-charts introverted by nature, so this was initially a very difficult endeavor which required years of study and practice to achieve competence. The point is that all people who reach a high-level in any type of performance make sure their body and mind are in the correct state before they begin.

Here’s my routine. I usually do this just before being released from grid to head to the start:

1. Hold your two hands up to either side of the wheel but don’t grip it yet. Now, without hardly making any movement, push your arm joints open. First the shoulder joint, then the elbow, then the wrist, then the palm, then extend through all the finger joints. Think of a wave of expansion traveling down your arms. Now relax and allow all the skeletal muscle to hang from the bones. Do this three times. Push the joints open, release the skeletal muscles. One more time: push the joints open, then totally release the skeletal muscles.
2. Now grip the wheel lightly and release the shoulders and elbows, sinking down until the entire weight of the arms is hanging from your hand grip. Focus on feeling the weight of your arms pulling down on your neck and upper back and your hands. The weight of the arms is producing a light stretch in your shoulder, elbow and wrist joints. (This is pulling the joints open where step 1 was pushing the joints open.)
3. With your foot, tap the gas pedal, then the brake, then gas, then brake, then gas then brake. If you left foot brake you should also move the left foot around and tap the brake and the rest point a few times.
4. Now gaze out the windshield into the distance, seeing everything out in front of the car, both what’s straight ahead and what’s in the periphery, and say to yourself, “Now, now, now, there is only the now.”

Explanation

Some people (like me) are naturally untrusting and need an explanation before they can attempt anything. This is for those people.

Steps 1 and 2 are a standard procedure in some internal arts like T’ai Chi Ch’uan and Chi Gung. The idea is to activate and stretch the fascia while relaxing/releasing the skeletal muscles. This promotes blood flow to the hands. This immediately increases the tactile sensitivity in the hands and activates the neural pathways that control movement in the arms.

Step 3 activates the neural pathways down to the feet, priming everything for action.

Step 4 is to “get you out of your head” and into the moment. This is to set your mind up to drive what you see and feel. We want to make sure you’re not trying to “remember” the course and drive too much from memory. It takes huge processing power for a beginner to “remember” the course, taking away from the ability to actually drive.

Key Driving Skills

I think there are several basic driving skills that the novice should begin developing during the first year of autocross. As mentioned in Part 1, the idea is to focus on what’s most important at the beginning.

• Develop a steering method that maximizes feel and control while limiting hand repositioning
• Learn to put weight on the front tires prior to turning
• Learn to add throttle in coordination with opening the steering wheel
• Learn to trail-brake
• Learn basic line theory

Develop a steering method

We wish to develop a method that maximizes feel and control and limits hand repositioning to a minimum. In the end (and also in the middle, as well as in the beginning) being able to drive a car fast and stay within the autocross course is highly dependent upon your sensitivity to what the car is doing.

Most of the information as to what the car is doing will come to your hands through the steering wheel. We also get information through the seat and a fair amount actually comes through your feet, especially when you’re braking. The beginner should focus on the hands.

First point: Drive with two hands!

I know this seems obvious, but you might be surprised how many times I’ve seen people drive with one hand on the wheel and one that never leaves the gear shift lever. Palming the steering wheel with one hand through the entire course is a recipe for incredible slowness.

So, keep both hands on the wheel at all times except for the minimum time necessary to shift. Once the shift is complete, put the hand back on the wheel.

Second point: For maximum sensitivity, get the maximum amount of skin on the wheel.

Don’t drive with only the fingertips. In the picture below notice that the fingers are wrapped, all five fingers tips are touching the wheel and the palms are making good contact the wheel. Also, I like to position the hands just below 9 and 3 o’clock to get a little more rotation before having to reposition. A lower position for the hands also promotes relaxed, in-the-socket shoulders. Sinking down the neck, shoulders and elbows is key to sensitivity and control.

A common habit, one I sometimes still fight, is for the hands to creep up to the top of the wheel, as shown below. Don’t do it! This lifts the shoulders out of the sockets and significantly reduces control and sensitivity. Also, from here you can’t make a big turn without repositioning the hands in the middle of the turn.

Third point: Reposition the hands as little as possible.

In some cars, like the Cadillac CTS-V I started with, many repositions are required. By necessity, I got very practiced at shuffle-steering and it became a habit I had to break later. “Real” race cars generally have a steering ratio such that repositioning is never required, at least on a race track. Sports cars today are generally somewhere in between when it comes to maneuvering around an autocross course.

There are multiple steering philosophies and techniques. Read about them. Try them out. I’ll show you what I do, below.

Case 1: For a significant left turn, use both hands to turn the wheel, the right pushing up from the below 3 position and the left hand pulling down and then moving across your lap, having not totally let go but allowing the wheel to slide through the Tiger’s Mouth. Note that the logo in the center of the wheel has turned more than 180 degrees from center. Both hands are still in contact with the wheel and are providing information.

Case 2: If the turn is so tight that repositioning can’t be avoided, say in a tight left turn, I will preposition both hands as I approach the turn-in point as shown in the figure below. The left hand moves around and over the top, the right hand moves around and down. Then I’ll rotate the wheel initially with the left hand until it’s down below in the lap, while the right hand takes over and pushes the wheel over the top. The end position is the same as in the figure above, except that the wheel will have been turned 360 degrees or even a little more without shuffling the hands during the turning process. Unwind by doing these actions in reverse. A turn to the right is just the opposite, of course.

I think this one-time, preparatory reposition of both hands is better than shuffle steering. When shuffling, each shuffle only produces about 160 degrees of wheel turn, so it takes three shuffles to get a full rotation.

Learn to shift some weight to the front tires before turning

Shifting some weight to the front allows the car to turn much harder and faster because the front tires give more traction. This means you don’t have to turn as early. By shifting weight forward you also increase the transient response capability of the car.

There’s exactly one thing that shifts weight to the front: decellerating the car. This can be done by lifting or applying the brake or both. Simple, right? It’s a matter of practicing this technique in order to get the timing correct. The timing is different from car to car and setup to setup.

Two exceptions:

First, turning while accelerating. Now you have to be a little careful. Why? Because now weight has shifted backward from the front to the rear tires, so the fronts will be down on grip.

Second, short-gap slaloms. If the cone to cone distance is not large there isn’t enough time to even lift for each cone and then accelerate in the gap between the cones, so it’s better to go though at the maximum constant speed. For long-gap slaloms and almost all autocross offsets it pays to lift for each cone and add gas within each gap. If the offset is big enough you will even have time to accelerate hard and brake hard within each gap.

How short is short? How long is long? It depends upon how responsive your car is, meaning both how fast it can change direction and how fast you can change from a lift or brake to significant acceleration. This is why transient response and instant engine torque are so highly prized in autocross. This is also why there’s so much argument as to proper slalom technique. Everyone is right and everyone is wrong, depending upon the car and the gap distance between cones.

All other times you turn the steering wheel you should have already shifted some additional weight to the front. There’s no crying in baseball there’s no coasting into a turn in autocross.

Learn to add throttle in coordination with opening the steering wheel

The slowest point in a corner is called the apex. From that point you can begin opening the steering wheel.

For every little bit that the steering wheel opens the lateral forces on the tires decrease. That means that they have molecules sitting around not working as hard as they can. So, put them to work! How? Start adding throttle. How much? As much and as fast as the tires will take. (Too much too fast and generally the car will begin to oversteer if it’s rear wheel drive and do the opposite if front wheel drive.)

Do not wait until the car is going in a straight line to add power!

Learn to trail-brake

Trail-braking into a corner is simply the opposite of adding throttle on the exit. Most autocross corners should be driven like the figure below.

Unlike on a race track, the braking point will usually be very close to, or even the same as, the turn-in point because of the lower top speeds in autocross. Initially brake hard. Then, as soon as you start turning, begin trailing off the brake pedal. As lateral force increases from the tires you must reduce braking or the tires will be overburdened. Theoretically you finish braking right at the apex when the tires are at maximum lateral force and then switch to gradually adding power as you unwind the steering wheel, as discussed earlier. It’s more important to begin adding throttle right from the apex than to perfectly release the brake right at the apex.

Learning to trail-brake on a race track is difficult and can be dangerous. Autocross is the best place to learn it. Start now! When perfected you will be significantly faster. If you then go to a track it will be automatic.

Learn Basic Line Theory

Certain basics of line theory should be quickly learned.

Set up left to turn right. Set up right to turn left.

This rule is not quite as simple as it may seem. Let’s take a 90 degree left turn as shown in the figure below. Very simply, don’t take Line 1 because the minimum radius is the tightest, meaning that the minimum speed will be the slowest. This assures that the time through the corner will be longer.

Don’t take Line 2 because the minimum radius, while bigger than Line 1, is still as not as large as it could be and the path is longer.

Do take Line 3 because the minimum radius is much larger than either Line 1 or Line 2. Therefore, a) the minimum speed in the corner is much higher, and b) that means you don’t have to brake so much coming in, and c) that also means you exit the corner faster and carry that higher speed as you accelerate out of the corner. These effects far outweigh the extra distance travelled compared to line 1, including the extra distance it took to get set up to the right based upon the initial location of the car as drawn, even if there is not a long straight after this corner.

Turn Pinched Entries Into Chicanes

The entry to a corner is pinched when it doesn’t naturally or easily lead to the biggest possible radius through the corner. In the figure below, the best line is the dashed one, but the entry gate makes that impossible. This situation occurs often in autocross.

So, keep your speed up and turn out to get on that best line, the solid one in the figure. This maneuver is a chicane, i.e. two corners in opposite directions close together. The bold path below is the faster one even though the entry path is significantly longer.

A rookie mistake is to head almost straight for the turning cone, slam on the brakes and start a sharp turn as you go by. That’s the dotted path. Don’t do this if you don’t have to. (Sometimes you may encounter courses that give you no choice.) While the car will get to the turn cone faster you will have to slow the car considerably while approaching that point and continue slowing after that to get turned toward the exit gate. Effectively, you will have moved your actual apex (slowest point) to somewhere around the “Slow Line” arrow tip and the car will be very slow because of the tighter radius required.

To add insult to injury, the slow line means you will be starting to accelerate from a slower speed and from a later point, reducing the length of the acceleration zone. All in all the slow line will totally ruin your run time. I see lots of new autocrossers, especially those in powerful cars, do this over and over, for years. It’s very dynamic and fun, and it seems like you’re really killing it out there, and you may tell yourself that you’re making up time by using all that power, but the clock says otherwise.

Don’t Go Wide On Big Corner Entry

By big I mean a corner that turns 120 degrees or more. In the figure below it doesn’t pay to take the 90 degree wide entry for the 150 degree turn, for example. Generally, for corners more than about 120 degrees going wide on entry does not increase the minimum speed in the corner, so you don’t get the same payback as with a smaller corner.

The correct radius to take the 120 degree or 150 degree turn, assuming complete freedom as shown in the figure, is a very complex subject, is dependent upon many factors and is way beyond the bounds of this post.

How To Drive Offsets

A series of offsets looks like this:

On a small lot it’s unlikely that you’ll see such a long series of offsets, but you’ll probably have one or more shorter features that are actually offsets. Make your transition (change from turning one way to turning the other way) about half way in between the cones. In addition, most offsets have enough total distance between the cones that you should be at least lifting on entry to the turn around the cone and then accelerating through the gap between cones, even though the car is always turning and never going straight.

If the car travels in a straight line in the center of the gap between cones then either 1) you are probably driving too slowly and too tight around the cones, or 2) it’s not an offset because the distance is so far between cones that they are actually separate corners.

How To Drive Slaloms

Let’s start with the simplest slalom: three cones in a row. Geometrically a slalom is an offset, like in the figure above, but with the b dimension equal to zero, or almost equal to zero.

There is much argument about how to drive slaloms, but for the basic 3-cone as shown above most would agree to enter early, meaning cross the center line before the midpoint between cones, and leave late, meaning cross the centerline after the midpoint between cones.

This produces a middle arc with the largest radius which in turn allows the fastest speed to be maintained. It almost always pays to do what’s necessary to set the car up to achieve the early cross. It does not pay to slow in the middle to achieve a tighter turn around the middle cone in order to add gas early on the exit.

At the transition point, the point where you must turn the wheel to change direction, turn the wheel as fast as possible. Take advantage of every bit of transient response the car can deliver. Anything less requires the car to be traveling slower to miss the 3rd cone.

For a slalom with more cones the exact same theory applies as shown in the figure below.

In slaloms with more than three cones start early and end late, proportioning the difference equally so that the arc radii are all as large as possible. Start accelerating as soon as possible in the last gap, but, just as in the 3-cone slalom, don’t slow around the next to last cone to produce a tighter arc in order to move the acceleration point earlier. Similarly, except for the first one, don’t backside all the cones in order to produce an earlier acceleration point in the last gap. It does not pay off unless the car has tremendous acceleration capacity combined with poor cornering power, like maybe 650hp with skinny tires on the front and drag radials out back. Maybe.

OK, that’s about it. I think most people can make a good start on all of the above points in about 20 events. Now you have lots of things to work on at a Test & Tune event this Spring.

Frequently when we see great performers doing what they do, it strikes us that they’ve practiced for so long, and done it so many times, they can just do it automatically, But in fact, what they have achieved is the ability to avoid doing it automatically.

When we learn to do anything new-how to drive, for example-we go through three stages. The first stage demands a lot of attention as we try out the controls, learn the rules of driving, and so on. In the second stage we begin to coordinate our knowledge, linking movements together and more fluidly combining our actions with our knowledge of the car, the situation, and the rules. In the third stage we drive the car with barely a thought. It’s automatic. And with that our improvement at driving slowed dramatically, eventually stopping completely. 

By contrast, great performers never allow themselves to reach the automatic, arrested-development stage in their chosen field. That is the effect of continual deliberate practice-avoiding automaticity. The essence of [deliberate] practice which is constantly trying to do the things one cannot do comfortably, makes automatic behavior impossible.

From Talent Is Overrated: What Really Separates World-Class Performers from Everybody Else, by Geoff Colvin, 2008

Stage 1: Training the mind to learn the course prior to the first run

When we learn to autocross we go through stages. Unfortunately, there is not yet a firm consensus of what those stages are and how to best train for the transition through them. However, I have certain opinions on the subject.

This will not be a surprise to anyone who knows me!

I think three stages can be usefully identified and trained in order. I’m not sure how many posts it will take to get through them, but we might as well get started.

One caveat: The stages that we use to break down the learning of any skill are never absolute. They are a creation intended to support the design of a particular method of training. Hopefully it is a training method that was developed by someone with experience and skill. Since the training method is by nature designed not all designs will be equally effective, though any two different designs may be equally effective as long as they’re each followed faithfully.

In the art of Taiji that I practice there are commonly thought to be three basic stages. I heard a teacher remark that, while we are actually learning bits of all three stages almost from the beginning, it is important to focus on each stage in order. He referred with sadness to certain schools that basically skip the first stage and begin and concentrate on stage two, either by choice or ignorance. It’s not that one cannot make progress in stage two without stage one, but the progress is limited and the art is forever incomplete without mastering the stage one skills. I think autocross is similar, and one of the problems for beginners is that you tend to get all sorts of advice from well-meaning people, but the advice may come from what really should be different stages. This makes it difficult to figure out which advice to listen to and focus on.

One thing is for sure: we cannot be fast when the course is a series of constant surprises. Most beginners soon realize this, but may not know what to do about it. It takes them many tries at the course before it begins to click. In the beginning it may take more runs that you get in the day, so you never get to the point where you drive the course with confidence.

This is a problem unique to American autocross. The course is different at every event and we don’t get to practice it. We only get to walk it. Every run is timed and we only get a few runs. Only the fastest run counts.

I’ve heard (and read) many advanced drivers say “seat time is all you need.”  

Seat time is needed, of course. But it’s not enough if you wish to get fast, fast.

Beginning with a club that offers at least six runs during a day (and hosts many events each season) is very advantageous because it may take that many runs to develop what a more advanced person would still call only a basic knowledge of the course.  But, that sixth run may be the only one that’s really fun that day if it’s the only one where you aren’t worried about getting lost, even momentarily.

The mind can only do so much. If your focus is on recognizing the features within the course as you’re driving, then it can’t be on other things like surface composition, slight camber changes, grip changes, etc. So, we need a good way to quickly nail down our knowledge of the basic course layout so that we don’t have to focus on it as we drive. I call this learning the course.

Learning the course is a mental skill that requires development over time. The good news is that, as far as I can tell, anyone with normal mental capacity can become very good at it. The mental operation will become easy or at least easier. Like anything else it takes practice. But, what type of practice? Well, that’s why we do a course walk, right?

Do you think walking the course aimlessly is going to do the trick? Or, worse, walking the course distractedly? Or, even more depressing, how about walking the course with great focus, but focussed on the wrong things? None of these are likely to produce a good outcome anytime soon.

Now there are levels and levels for this sort of thing. The amount of detail that can be registered during course walks can vary tremendously from person to person. This is no different than expert-level achievement in any field. Experts always see more and remember more. You want to be an expert, right? OK, let’s go!

So, how do we get started training the mind to learn the course? We walk the course in a deliberate practice* sort of way. I recommend two disciplines. First, walk the course as many times as possible with mental focus. Your focus should be on imagining driving it at each point, at each step you take. Remind yourself to look ahead at each point in the course. Deliberately gaze way ahead and take in the view from each point. Decide where you should be looking at each location, both the direction and what items you will focus on, what cones you will wish to pick out and clearly see at speed and then do it.

Second, stop walking from time to time and draw the course, piece by piece, section by section, multiple times. You must have a pad and pencil with you as you walk. Break it down into sections. Once you have the sections, think about the transitions between sections. Don’t even try to connect it all together into one whole. It’s not necessary to be able to imagine driving the entire course in one continuous sequence. Save something for year five!

These two disciplines, walking with a particular focus and drawing the sections, are not necessarily “fun” in the normal sense of the word. They require mental work. You can’t be talking to your friends as you walk. (At least not the first few years.) You can’t be listening to someone else describe how they are going to drive the course. While that may be a very good thing to do from time to time, or on one of your multiple course walks, it will not help the training if you’re talking or listening on every course walk.

A caveat: Do not try to memorize the course. Walking the course with focus and drawing it is enough to make it seep into your subconscious. Not much will be surprising when you drive it. That’s all you need, because, we do not want to drive from memory. That would be too automatic as described in the quote from Talent Is Overrated, above. Every run is different. You must continually strive to drive faster each run, continually testing for the limits of traction, continuously improving your line. If you never feel the tires slide you’re not doing it right. Local conditions are always changing throughout the day. Your knowledge and feel for the course continually improves run to run. Your physical, emotional and mental states are constantly changing from moment to moment and, on some days, will affect your driving speed more than big changes in local conditions. Humans are not (yet) robots.

If you do these two things for 25 events, which is usually about one year for the moderately obsessed, you will probably be ready to focus on stage 2. But, don’t ever stop walking the course with focus and continue drawing the course for at least 50 events. Maybe that’s two years, maybe it’s five or even 10.

Examples

Below is the course map for our last local event in 2023. I’ll go through it as I would as a beginner, creating meaningful sections that I can remember and then string together. That’s step one. Then step two is to think about key transitions, or set-ups, between sections.

Section 1: Turning start into offsets

Section 2: 90-right into accelleration zone

Section 3: Slalom into the Hump

Section 4: Offsets into decreasing radius turnaround

Section 5: Fast 90-left into increasingly fast slalom

Section 6: Weird offset into a short finish

I suggest you read the names above and see if you can follow along on the map.

I reduced the whole course to six sections and six section names/descriptions. You don’t want too many… most people can remember about five to seven items, such as pieces on a chessboard. The funny thing is, the “items” can be single things or meaningful groups.

Non-chess experts, when shown a board with 20 to 25 pieces taken from actual games and then asked to recreate it, were found to be able to place only 4 or 5 pieces correctly. Chess Masters could generally recreate the entire board. They don’t remember 25 individual pieces, however. They remember five to seven recognizable groupings that have meaning within the game.

If the chess pieces were placed randomly, the chess experts could not remember any more than non-players. Similarly, if you try to memorize each turn in order within an autocross course… well, it’s basically hopeless.

When you first start autocross none of the course features mean anything to you, so remembering even five to seven groups will be difficult. You will, however, immediately begin to hear or read about named features, such as turnarounds, slaloms, offsets, decreasing and increasing radius corners, etc. You need to pick up on the lingo and ask people what the heck they’re talking about!

Here’s the map again, as I mentally separated it into 6 sections, numbered and with red-dashed dividing lines.

It doesn’t really matter how short or long each section is. What counts is that each one has a clear meaning to you as described by the words.

Part of the way I broke up the sections has to do with being able to see (when driving) all or most of the next section from the entry of that section. I think this is very helpful.

Another factor in how I broke the course into sections has to do with key setup points. For instance, between 1 and 2 I want to remember to stay tight left at the end of 1 (arrow) in order to be in a good position to enter 2.

I include the “acceleration zone” with the 90-right because it will remind me to add gas (arrow) as soon as possible coming out of the corner.

Similarly, at the end of 3 I need to remember to set up near the cone wall for the first turn cone of section 4 (arrow).

I include the decreasing radius turnaround as part of the section 4 description because what that means to me is that I must carry a lot of speed into the turnaround, only gradually slowing until the apex.

And then at the end of 5 the words “short finish” remind me that there is no setup for an acceleration into the finish because it comes up so soon. Therefore, I want to carry huge speed into section 6, brake and jerk the wheel hard right at the end of the last wall of cones (arrow) and continue to carry as much speed as possible around the last cone until I (hopefully) just barely miss the cone on the right side of the finish line. I anticipate that the car may be gradually slowing down the entire time in this section.

Here’s another example: the course map for the event previous to the one above. Please ignore the fact that “autocross” is misspelled!

Maybe you want to divide it up yourself? If so, go ahead and do it mentally before looking at how I did it.

Here are my sections descriptions.

Section 1: From Start, accelerate into a series of offsets

Section 2: Accelerate into a 90-right

Section 3: Turn left into a long acceleration zone

Section 4: Super-fast right sweeper into odd-spaced walloms

Section 5: 180 turnaround

Section 6: Two hard rights into the finish

…and the sections are illustrated below.

Once I have the sections in mind, I then decide about the setups in the transitions from one to the other. These are:

Between 1 and 2: get on the gas as early as possible after the last offset cone, but then brake early for the turn

Between 2 and 3: Exit the 90-right very tight in order to carry the most speed around 3’s left turn

Between 3 and 4: Carry speed like I’m insane knowing I can always lift to tighten the radius

Between 4 and 5: Backside the end cone of the first wall in the walloms

Between 5 and 6: Don’t fail to move the car left to set up for the first of two right turns

That’s basically how I mentally approached this course. This means I’m not driving one corner at a time. I’m driving one section at a time, with a key setup point within or at the end of each one.

The next installment for Stage 1 will cover the key driving skills that I think need to be understood, practiced and then developed within the first year of autocross. These will include developing a steering method, learning to shift some weight to the front before turning, trail-braking, coordinating steering and throttle after the apex, and learning to always be setting up.

*Deliberate Practice is a term first coined by psychologist K. Anders Ericsson to describe how people actually become experts in any field

A friend of mine went to a Test & Tune event recently and used the opportunity to experiment with his shock absorber settings. He’d been running them full stiff in competition. He decided to start the day full soft and work his way stiffer.

At full soft the car became very loose with dramatic oversteer on corner entry. The oversteer/understeer balance gradually changed as he stiffened the shocks. He was working all four corners together, simultaneously making the “same” change to each shock.

He asked me this question: “How does [adjusting] damping change a car balance like this?”

Here’s my answer.

A basic tenet in structural design is that when a load travels through two (or more) paths, the load preferentially and proportionally follows the stiffer path(s). So, changes in stiffness alter the proportioning of load, say transient cornering loads, from one corner or one end of the car to the other corner or end. Since shocks only create forces that oppose motion, roughly in proportion to how fast the shaft is moving, they become variable, non-linear stiffness elements in the load paths, parallel with and additive (bump) and subtractive (rebound) to the steel spring stiffness. The forces they produce are the dominant effects that shocks have on car handling balance, not energy absorption, i.e. not “damping,” but we will talk about both. 

The cornering load can preferentially go to one end of the car or the other. If it can’t be resisted by the tire patch at that corner, then that corner starts to slide.

However, shocks act mostly only during transients when the shock shafts are moving, say during corner turn-in. Steady-state cornering balance is not significantly affected by shock settings because at that time the shocks have stopped moving and are not producing any force.

Now, this last is not strictly true in reality. The shock shafts are always moving to some extent because no surface is completely flat and smooth, plus the damned driver keeps turning the steering wheel, even if only in small, short motions! This is part of why shock valving has a significant effect on the total grip even on relatively smooth surfaces. During steady-state cornering when the shocks are not moving the understeer/oversteer balance at the limit is mostly determined by front-to-rear tire grip differences, weight distribution, spring stiffnesses and anti-sway bar stiffnesses.

That said, the first key point I want to make is that the front and rear shocks are usually not valved the same and generally not acting through the same geometry and motion ratios. So, even though you may think you are changing all four the same amount, say 2 clicks each, it’s not actually the case that the damping change is equal at each shock or wheel. The oversteer/understeer balance at the limit is almost certainly being altered even though you think you’re making equal changes at each shock. Of course, if you change just one end, the effects on car balance are increased. 

My second key point is that while shocks do absorb energy, perhaps more importantly they affect the timing of energy delivery to the tire contact patch. Let’s talk about energy absorption first and timing second.

When a car turns into a corner there’s a finite amount of momentum created by the turning action. The shocks on both sides of a turning car absorb some of the kinetic energy associated with that momentum by doing work (force x distance, converting kinetic energy into heat) and they also alter the distribution of load around the four corners by being stiff elements in the load path. Most of the kinetic energy is not absorbed by the shocks and ultimately becomes either temporarily stored in the outside springs (and it’s going to come back out!) or transferred as load to the tire contact patches. If you soften the shocks less energy is absorbed leaving more to hit the tire patch, since the amount of energy stored in fully compressed or fully extended springs is always the same. Soft shocks will allow a faster peak roll motion, in terms of degrees of roll per second, which can affect what happens at the tire patch later when the roll motion is finally snubbed at the end of the roll. All rolls must end.

When the shocks are set stiff they generally absorb more energy early in the roll (both the compressing and the extending shocks) and slow the roll by opposing it with force. This actually transfers load, lateral load (not weight!) to the tire patches sooner in the cycle, thus improving transient response by speeding up the transfer of lateral load to both tire patches, left and right. Theoretically this can act to reduce load shock to the tire patches at the end of the roll and thus help prevent the tires from losing grip. There is literally nothing worse than a car that’s so soft and has so much suspension travel that everything seems fine on turn in until the roll gets snubbed at the end and suddenly all hell breaks loose.

On the other hand, shocks stiff in rebound but not compression act to resist roll only by pulling vertical load off the inside tire patch as the car begins to roll and the shock extends. This can also cause the car to lose grip very early in the turn if inside tire grip is the limiting grip variable. So, if you have a Koni Yellow, for instance, which is adjustable in rebound only, and you crank it up to full stiff, you do not increase the compression damping on the outside tires during turn-in. You only increase the rebound damping on the inside tire, the one with the shock that is extending. The weight pulled off the inside tire still becomes load on the outside tire. (Where else could it go?) My point is that the effects of rebound and compression damping are complicated and not identical opposites.

If stiffer shocks create forces that oppose roll while speeding up lateral load transfer, that necessarily means that lateral load transfer occurs early while the car is at a lower state of roll than otherwise and therefore the tires have not yet given up all the camber they will when full body roll is achieved.

Maybe you should read that last sentence again. I just wrote it and I’m going to read it again! I’ve never seen that fact in print before. Anywhere. It basically defines a mechanism for an increase in grip during the turn-in transient that is due to the shocks changing the timing of lateral load transfer with respect to “weight” transfer, not the amount of lateral load transfer and certainly not the amount of “weight” transfer.

And all this happens in about a second in a slalom.

Maybe we need a diagram.

In the diagram we have two forces shown acting on the tire: W stands for weight and L stands for lateral load. Just for fun and so you can develop an eye for it, the wheel in the diagram is actually tilted at 3.6 degrees of negative camber. (I meant it to be 3 degrees, but something happened.)

When we initiate a turn we get an immediate increase in L, the lateral load, and the stiffer the shocks the faster and earlier that load transfer… hopefully while some of that negative camber still exists, because that’s when tires are most capable. If we don’t have much damping force from the shocks then the full lateral load may not hit until the car is fully rolled, at which time we are left only with the final camber state, which in Street class cars can often be positive instead of negative. (Tires don’t like that.)

But when people talk about weight transfer across the axle, they are probably thinking about something different. They are thinking about an increase in W.

When the body rolls, “weight” is transferred from one side of the car to the other, right? Well, that’s a vague way of talking about it. Yes, if you could put a scale under the tires while cornering it would say that “weight” has shifted, but really it is vertical load W that has increased, due to body roll, on one side of the car at the expense of the other side. That load increase is directly related to how much additional spring compression has occurred on one side, balanced by extension on the other side.

It’s also very possible that if the shocks are too stiff at the shaft speeds produced by turn-in they can shock the tire patches too much, too early and cause one end of the car to give up grip during the turn-in motion. However, this effect is somewhat in the driver’s control because she determines how fast she turns the steering wheel. All production car shocks and springs as delivered that I’ve ever slalomed are so soft that the driver can turn the wheel as fast as humanly possible and not create an immediate problem before you must turn back the other direction. At least on a dry surface. Sure, if you turn the wheel fast enough and far enough you can induce understeer in just about any production car. They are designed to do that. On purpose.

In any case, these dynamic effects are complicated and not well-understood by most casual autocrossers, automotive journalists and even some racing mechanics and engineers. Many books and articles about tuning car handling with shock changes are incomplete in their explanations and over-simplify the situation, offering various rules of thumb for tuning the balance with shocks. W in the diagram does increase faster with soft shocks because the car rolls faster. This is almost always a bad thing. So, look at the diagram again. An increase in W does not cause the car to turn. In fact, while increasing the lateral load capability of that tire, it decreases peak capability for turning because the inside tire is now lacking in vertical load and the sum of the two capabilities is less than if no weight transfer occurred. (We prefer to minimize weight transfer across the axle if at all possible. Usually the best way to do this is to lower the center of gravity while increasing the track width. Notice how wide and low most supercars have gotten in recent years? Much wider than necessary to hold two occupants comfortably, side by side.) An increase in L is what causes a car to turn and a fast increase in L allows a car to change direction quickly, with or without a significant increase in W.

If you take anything away from this post it should be this: the speed of lateral load transfer to the tires is a different effect from the speed of “weight” transfer to the tires caused by body roll and only one causes a car to turn. Both are highly influenced by shock absorber performance.