The Art & Science of Passing – Use a little of both next time you encounter an overtaking situation

The most exciting element of motorsports is passing a competitor, especially for position. It’s even more gratifying if the pass is for the lead. It’s also a perilous time for the passing car and the one being passed. In club racing, and especially in Time Trials and HPDE sessions, there are strict rules about passing and about car-to-car contact, which is a big no-no. Since rules are always scrutinized and interpretation is often in the eye of the beholder, I encourage you to do a quick review of the NASA CCR section that covers passing. It’s covered in section 25.4 in your CCR. Go ahead. I’ll wait.

Are you back? Good. Let’s move on.

As you know, the rules are specific on paper, but can get tricky in real life. A conflict exists in the section of the rules where the passing driver is responsible for making a pass safely — meaning no contact — and where the driver being passed must leave room for a car making a pass as long as an overlap exists. In other words, when the passing car’s front bumper overlaps the rear bumper of the car being passed, the driver of the car being passed must leave room. But if the driver of the car being passed turns down into the passing car after the passing driver has a slight overlap and contact occurs, who is at fault?

It would be the passing car, as described in the CCR Figure 1 in the Appendix, but in a very real sense, it makes no difference who is at fault relative to the race on the track. Both cars lose time and risk incurring damage, an off-course excursion or a black flag. Time lost, regardless of who is at fault and regardless of official decisions, is still lost. If a third car gets by due to lost time, then that position is lost unless you can get by again.

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But it’s rare for positions to be given back after the fact. Plus, it’s completely unsatisfying to win by protest in a steward’s meeting. Winning or even gaining positions on the track is much more fun. So let’s look at some ways to avoid touchy situations when passing:

  • Never assume the driver of the car you are attempting to pass knows you are there. This is especially true if the driver you are trying to pass also is trying to pass a car.
  • The closer the two cars are to the bumpers, lead car’s rear bumper and passing car’s front bumper, the greater the chance of a spin
  • The inverse also is true, when the passing car’s rear bumper and passed car’s front bumper overlap at the exit.
  • If you can only manage a slight bumper-to-bumper overlap, it’s usually better to leave room and wait to make the pass later.
  • If you have made the pass cleanly, but your rear bumper may overlap with the front bumper of the car you are passing, leave room to the outside of the corner for the passed car. If you clip the car behind on his front bumper, you will likely spin off and technically, it will be your fault for not making a safe pass.
  • It is always best to assert your position when making a pass into the corner.

Let’s explore that last point more completely. Asserting position when making a pass into a corner means that the overlap is great enough that the driver of the car being passed can see the front of the passing car in his/her peripheral vision. The front of that passing car is at the “A” pillar of the car being passed, or when “the front wheel is next to the driver,” as expressed in the CCR. This assures two things: the driver being passed has no excuse for not knowing you are there and if the driver being passed turns down on you, then at least the contact will not be at the ends of the cars where a spin is more likely, but side to side where both cars are more stable if contact occurs. It also minimizes the chance of you getting black flagged if contact occurs.

It is always best to assert an overlap under braking before turn-in. If you do this then the other driver is forced to wait to turn in until you turn in, assuming your passing to the inside. But you can still assert your position clearly if you are along side the car you are passing a ways before the turn apex. Keep in mind that if you turn in early under braking, you can brake later since you are taking a straighter line into the corner. But the consequence of this is that you apex earlier and you will not be able to get on full power as early as normal. More on this later.

Now that we have looked at rules, consequences and practical ways to attempt passes, let take a look at some real-life scenarios.

The Easy Pass

The easiest pass to execute successfully is on a straight. Sometimes, in a spec class, passing on the straight is about the only real option. The key to passing on a straightaway is to focus on getting a good run off the corner leading onto the straight, then drafting the car you are trying to pass. If you get a good run off the last corner, and you are within five car lengths of the car ahead as you exit, you have a chance of drafting into position. If you cannot make up enough ground on this straight, you may need to wait until the next straight or the next lap.

If you are catching the car in front early enough on the straight, then you can pull out of the draft using your momentum to make the pass, or at least get alongside the car you are passing. The biggest mistake racers make when drafting to set up a pass is to pull out of the draft too soon. If you are gaining ground on the car in front quickly, you should have enough momentum to make a clean pass before the braking area for the next turn. But if you pull out of the draft of the car in front too soon, the aero drag will stop your momentum quickly.

This loss of momentum also can occur, if you pull too far away laterally from the car you are passing. Depending on the type of car, body shape and aero package, the wake left by the car in front can be as much as one-half of a car width wide at the front of the car and slightly wider at the rear of the car. So by staying close to the side of the car you are passing, you will still benefit from the draft until your front bumper is just aft of the other car’s front bumper. But the farther away you move laterally from the other car, the less aero advantage you receive. Many passing attempts on a straight fail because the passing car swerves to far away from the car being passed. The passing car hits a turbulent wake and momentum is lost very quickly.

On the other hand, if you are not really gaining much ground on the car in front while drafting, your best bet is to stay in the draft as long as possible, then attempt to out-brake the other car into the corner at the end of the straight.

Passing
Whether you are attempting to pass on the inside or the outside, your front wheel must be even with the door of the other car.
Whether you are attempting to pass on the inside or the outside, your front wheel must be even with the door of the other car.

Corner Entry Under Braking

The classic pass is under braking entering a corner. Unless you can make a clean pass on a straightaway, passing under braking entering a turn is the easiest. By utilizing the drafting technique as explained above, you can get within a half car length of the car in front. Ideally, only a few inches will separate the following car from the lead car. Here is where your anticipation skills come into play. It helps to know the driver in front of you is consistent. The reason is you need to pull out of the draft to the inside just an instant before the lead driver begins braking. If you time it right, you have a full car length to the inside before you need to brake. And if you have planned the pass so you turn in slightly earlier than usual, you can brake even later.

But here is where care must be taken. If you turn in too early, you will be in a poor position to carry speed at the exit, and the astute driver you just passed will easily re-pass you early along the exit straight. But if you have been able to assert your position before turn-in by moving alongside the leading car early in the braking zone, then you will be able to dictate when the outside car can turn in.

Even if you are not past the lead car, but alongside — your front bumper even with the other car’s “A” pillar — then the outside car cannot turn in until you do. By using this technique, you can turn in at the optimum point on the track and force the outside car to turn in a little later than would be desirable. This gives you as the inside car, the optimum exit line and a much better chance to be ahead and clear of the car you just passed by the track out point at the exit. This means you can be back on the power at the usual time. Now you just have to defend your position from retaliation

Never assume the driver of the car you are attempting to pass knows you are there. This is especially true if the driver you are trying to pass also is trying to pass a car.
Never assume the driver of the car you are attempting to pass knows you are there. This is especially true if the driver you are trying to pass also is trying to pass a car.

Corner Exit

Passing at the exit of a corner can be effective, especially when cars are equal, as in a spec class. The classic technique is to draft down a straight, faking a pass attempt from the draft in order to encourage a defensive move from the car you wish to pass. The defensive move is often an early turn in to block an out-braking attempt.

If the lead driver does this, it puts you in a position to use a later turn in, a late apex and the opportunity to get on the power earlier than the lead driver, who has apexed early and will not be able to get on the power as soon. This works especially well when the next corner where braking is necessary turns in the same direction. If this is the case, you only need to get along side the car you are passing to gain an advantage going into the next braking zone and corner.

Racing Side By Side

Often, when attempting to complete a pass, you end up racing side by side. This is a time to analyze the situation from a realistic perspective. Will I have the advantage going into the next corner? Or will the other car? Are other cars in position to catch up while you are trying to complete the pass? Racing side by side always costs time on the track for both (or all) cars. If you need to get by the car in front to catch other cars ahead, or you need to defend from behind, it is better to bite the bullet, drop back in line an attempt the pass at the next opportunity. Making judgments based on the reality of the situation is crucial in these situations. Wishful thinking will only cost you time, and most likely positions on the track.

After A Pass

Ironically, the most vulnerable time to get passed is right after you make a pass, especially if the car you just got around has an advantage on corner exit, or if the cars are equally matched, as in a spec class. The vulnerability comes from the reality that the passing car most often must change entry lines, braking points and exit lines to complete the pass. At some point, the passing car is going to be slower than normal, giving the passed car an advantage if the driver of the passed car is using the situation to his or her advantage. And that is exactly what the passed driver should be looking for. And then the passed driver can counterattack the car that just completed the pass.

As is often the case, the best defense in this situation is a good offense. The more you can assert your position early on when attempting a pass, the easier it is to defend. If you can get by on a straight or under braking, then you can control the line through a corner and especially on the exit of the corner. But if you only manage to get alongside entering a corner, then you are in a vulnerable position to be passed again. This is especially true if you had to turn in too early to out brake the other car. This leaves the passed car the option to turn in a little later than normal, getting on the power earlier, changing the exit line slightly so that the car is positioned to make a run on the exit straight. There is little you can do if this scenario unfolds.

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According to the rules, a car being passed is only required to yield three-quarters of a car width.
According to the rules, a car being passed is only required to yield three-quarters of a car width.

Lapping Traffic

Passing lapped cars occurs regularly in endurance and mixed-class racing. But in either case, the goal is always the same: lose as little time as possible. When lapping slower cars, you usually have a speed advantage, but not always. In some cases you may have a car with faster lap times, but the car you are trying to pass has more power, so you cannot get by on the straights. In this case, it is most important to gain an advantage under braking so that you can use your car’s superior cornering speed to get far enough ahead so that the other car cannot re-pass on the following straight.

More normal are situations where you simply come up on slower cars. But passing is always risky, even when you are clearly faster. Being hyper-alert is crucial in lapping situations. Does the car in front know you are ready to pass? Has the corner marshal waved a passing flag? Has the driver looked in the mirrors? Has the other driver given you a point-by? If the answer is no to all of the questions, then the risk factor is greatly elevated.

In any case, it is important to time passes on lapped traffic in a way that allows you to clearly assert your position as quickly as possible. Corner exits and straights are the best places for lapping slower traffic. Asserting position under braking is next best. But if you have a cornering speed advantage, then even a mid-turn pass can be safely executed. In any case, if in doubt, wait for the next opportunity. Discretion is usually the best the tactic.

If you get right up on the bumper of a car that is passing another, it’s impossible for car being passed to close the door, which can result in multiple cars getting by.
If you get right up on the bumper of a car that is passing another, it’s impossible for car being passed to close the door, which can result in multiple cars getting by.

Being Lapped

If you are being lapped, your singular goal is to lose as little time as possible while being passed. The first key is to make as easy as possible for the passing car to get by you. But slowing more than necessary for, say a slightly altered line into a turn, is not in your best interest. The best way to make it easier for the passing car is to signal the other driver which side you want to be passed on.

You should always have the lapping car pass on the side that allows you to keep your line for the next corner, which almost always means have the car behind pass on the inside. Once you have signaled, make sure the passing driver is actually attempting to make the pass. Do not assume that, just because you gave a point-by, that the other driver is actually trying pass now. Once you confirm the pass is under way, hold your line and leave the other car room to get by. If done with care, you should lose very little time.

If you are embroiled in your own battle for position, then you have fewer options when helping the other driver get around you. If you are the lead car, then you want the lapping car between you and your opponent. But if you are the following car, that is last thing you want. So if you are the chasing car about to be lapped, you should attempt to control the situation so that the lapping car can pass both of you exiting a corner on to a straight. Then you can attempt to use the draft of the passing car to get by your rival. If you are in front in this situation, then you want to keep the lapping car in between for a little while so you do not lose your advantage.

Like passing, the best place to be lapped is on a straight or under braking for a corner. Being lapped any other place will cost a little more time.

Three wide at corner entry can be dicey, but many tracks are wide enough to do just that. The Keyhole at Mid-Ohio is plenty wide, but the outside can get pretty dirty with rubber “marbles.”
Three wide at corner entry can be dicey, but many tracks are wide enough to do just that. The Keyhole at Mid-Ohio is plenty wide, but the outside can get pretty dirty with rubber “marbles.”

Think Outside The Line

In my career, I have been fortunate to compete in many endurance races. The most enjoyable part of endurance racing is passing lapped cars. It is challenging and satisfying, at least when it all goes to plan.

In a club enduro at Willow Springs Raceway in California, I made the most interesting pass of my career.

While driving through Turn 2, I noticed that three cars several lengths in front of me were catching a slower car at the approach to Turn 3. It was clear that there would be a big, and time-costing logjam in Turn 4. The three cars caught the slower car at the apex of turn 3. The slow car held the preferred line into turn 4 (staying driver’s right for the early apex approach). The three following cars, now slowed to the speed of the slow car, all stayed on the same early entry line. I decided to take an unusual line into Turn 4. By late apexing Turn 3 and staying to the left edge of the track, I could take a late apex line into Turn 4 and accelerate hard before the second apex.

I figured I could get past at least one and maybe two of the four cars. I was wrong. I passed all four of the cars between the two apexes of turn 4. I was able to accelerate hard underneath all four cars. Only the second car in line (first of the cars caught up behind the slower car) decided to make a pass attempt. Before the second apex, he turned down to pass the car in front, but I was already about a half a length in front of him, so he had to leave room. I was a little slow at the second apex, but still faster than the other cars, enough so that I was able to gain a 10-car-length advantage going down the hill into Turn 5.

This was a surprising pass, but also a very satisfying one. The point here is that when you encounter a slow car, or groups of slow cars, it is important to look at the situation as an opportunity, not a problem. Look at all of the possibilities, then you can analyze the chances for success.

Defending A Pass Attempt

When racing for position, defending against passes is even more important than making passes. You already have the position. Losing it then attempting to get it back is much more difficult than keeping it. There are many ways to defend position. Most involve blocking. By the rule book, you can make one move to pick your line. Make two moves and it’s blocking. And making a move on a straight is mostly considered a blocking move.

On long straights, especially where you need to move across the track to set up for the next turn in the opposite direction, you can choose when and how you move across the straightaway. Most drivers choose to get across the track quickly to get set up for the following corner. This does things, both detrimental to defending position.

First, it allows the driver behind to draft, then drop out of the draft as the car in front reaches the edge of the track. This means the passing driver is moving one car width less, and is not having to make a second steering input, which causes slight, but significant tire scrub. Both give the rear driver an advantage. Second, the driver moving across the track earlier is scrubbing off a little speed early on the straight, which affects speed all the way down the straight.

By using the length of the straight, from turn exit to braking point for the next turn, less speed is scrubbed overall, but what is lost is lost later. It also gives the driver attempting to pass less distance to setup the pass and get around. In fact, the lead car is better off staying to the last turn exit side of the straightaway until midway down the straight or until be trailing driver begins to move across the track. This makes it very difficult for the trailing car to complete a pass.

If a car gets a run on you at the corner exit, there is not much that can be done to defend. But entering a turn is another story. The are many scenarios, but they are similar. Basically, you need to turn in early to defend. Too early and your exit line, and speed, will cost you and make an easy corner exit pass for the trailing car. But if you are being drafted down the straight, then the ideal way to defend against an out-braking maneuver is to watch your mirrors and when the trailing driver pulls out of the draft to initiate a pass, then you begin your turn in. But this only works if you are already at or in the braking zone. The trick is to not over brake if you turned in early, and to alter your line so that you have good exit speed.

Six Important Factors for Passing

  1. FOCUS OF ATTENTION

Where is your attention focused? Pay more attention to what the car in front is doing, or the car behind if you are defending.

  1. WHERE ARE YOU LOOKING?

Look ahead for opportunities. Check your mirrors. You do not want to get passed while attempting to make a pass.

  1. ANTICIPATE

Study the competition. Try to anticipate their moves. And always anticipate your own moves.

  1. KNOW ALTERNATE LINES

Try alternate lines in practice, or even in the race. This way you will know how your car will react, and you may get the track a little cleaner for a passing attempt.

  1. KNOW WHAT YOUR CAR WILL DO OFF LINE

This relates to the above, but knowing that you get, say rear wheel lock up in the dust off line many allow you to alter brake bias for a pass attempt. Or at least keep you from a nasty surprise.

  1. KEEP AN OPEN MIND

Look for opportunities and consider the possibilities. Passing other cars is one of the most exciting elements of racing. Becoming skilled at passing is like any other part of racing. It takes practice, good judgment and commitment.

It is always best to assert your position when making a pass into the corner. Sometimes it can take a whole lap to set it up.

Image courtesy of Don Wise Jr

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