Handy Motorsports Glossary of Terms
When you start participating in HPDE events, you’ll soon discover what may seem like a new language! Like many things, motorsports has its own lingo. This handy motorsports glossary of terms will help you learn key definitions when you’re getting started in HPDE. Plus, you can always refer back to it later when needed.
How to Learn Motorsports Terminology
Learning what seems like a new language for HPDE can be tricky, but there are ways to make learning new motorsports terms easier and more fun for yourself.
- Realize that you’ll be hearing words, phrases and acronyms that may or may not make sense to you. This is okay.
- Do not assume that what seems like a logical definition for something that someone said is accurate. Verify it.
- If you’re not sure what is meant by particular HPDE terminology, ask about it. Questions are always welcome!
- Remember that no one will ever look down on you for not knowing something. Everyone was new once.
- Realize that the instructors and other drivers were all in your shoes once and had to ask what is meant by different words, phrases and acronyms, too.
Learning the lingo can take time. Some words and phrases you’ll hear almost immediately from HPDE instructors and other drivers. Other terms are more advanced, so you’ll hear them more as you continue to be involved in motorsports.
Glossary of Motorsports Terms
The alignment of a vehicle suspension determines how the tires are positioned relative to each other and the chassis. Adjustment settings such as camber, caster and toe are used to tweak the alignment and improve performance and handling and reduce tire wear.
The anti-roll bar (or anti-sway or stabilizer bar) is a part of the suspension system that makes it easy to adjust your car’s balance. Thanks to its design, the anti-roll bar can increase stiffness in roll, without impacting ride.
The Apex can be thought of as the point in a corner where you are no longer entering — but transitioning to exit it. It’s the place where the car clips the furthest most inside point or area of the corner. An Apex can be right in the middle of the corner (geometric Apex), earlier than that (early Apex), or after that (late Apex). The Apex is also sometimes called the “clipping point.”
This is an adjustment setting that refers to how much of the total braking power goes to the front brakes. A brake bias of 52% means the front brakes get 52% of braking power while the rear brakes get 48%.
This could apply to either one of two things. First, the act of easing up on the throttle in a gentle manner, rather than lifting the throttle completely. Drivers typically “breathe the throttle” to make subtle speed and/or weight transfer adjustments. If you’re told to “breathe it,” be clear as to whether this is referring to what to do with the throttle, or your body… and that’s the second use of this word. When a driver holds their breath, they tense up, reducing the amount of sensory feedback they get through their body, which is not a good thing. The places most drivers hold their breath is in scary, challenging sections of the track, like fast corners and heavy braking zones. Drivers sometimes need to consciously be reminded to breathe until it becomes a habit to do so in those tough areas of the track. And that’s why your in-car instructor may say, “Breathe” to you over and over again.
Bump steer (or roll steer) is the tendency of the tires of a car to steer themselves without input from the wheel when they encounter a bump in the road and move through the suspension stroke. The right suspension and steering linkage setup can help minimize undesirable bump steer.
Aftermarket bump stops (or bump rubbers) are cone-shaped pieces of polyurethane placed on the damper to prevent the springs from compressing too far causing the suspension to bottom out and get damaged.
Camber is one of the key suspension alignment adjustments. When viewed from the front or back of the car, camber is the tilt of the tires away from vertical, given in positive or negative degrees. If the top of the tires tilt inward toward the center of the car, it’s said to have a negative camber. If the top of the tires tilt outwards away from the center of the car, this is positive camber.
Caster is another key suspension alignment adjustment. When you view your wheel from the side of the car, caster is the tilt of the steering tires away from vertical at the upper and lower steering pivot points. If the top of the tire tilts toward the front of the car, it’s said to have a negative caster. If the top of the tire tilts toward the back of the car, this is positive caster.
Every object has a center of gravity, and a track car is no different. For a car, the center of gravity is found at the intersection of three axes — pitch, roll and yaw. Your car’s center of gravity is not always in the middle of the car. It can be a point lower or higher or more forward or backward, depending on weight distribution.
A chicane is a serpentine curve often incorporated in the design of a track. A chicane has one turn in one direction followed by another turn in the opposite direction. You may also hear chicanes referred to as “esses.”
As you drive down the track, there is just a small amount of your tires that is in contact with the track surface at any one moment in time. If you look at your tires while your car is sitting still, it’s easy to see that the amount of your tire touching the road is relatively small. It’s this part of the tire that is referred to as the “contact patch.” If you push down on a tire harder, putting more weight on it, its contact patch grows larger (think of pushing a balloon against a table surface — the more you push on it, the larger the area becomes where the balloon touches the table). And, generally, the larger the contact patch, the more grip or traction the tire has with the track surface.
There are three main references — the Turn-in, Apex and Exit or Track-out points — that are used to define the line you drive through a corner.
This is a key part of your suspension with which you’re probably very familiar — it’s also called a shock absorber. Shocks minimize the effect of oscillations from the road surface and driver’s input on the car’s movement. Performance race dampers can be highly fine-tuned, with separate adjustments for compression and rebound and fast and slow suspension movement.
A double apex refers to a section of track where one turn is quickly followed by another, but unlike a chicane, both of these turns are made in the same direction.
Downforce is one of the aerodynamic forces acting on your car as it moves through the air. As the term implies, downforce puts downward force on the car. One advantage of this is that it makes for better grip, meaning you can travel through corners faster than would otherwise be possible.
Tailgating is usually a bad thing, but it serves a purpose in certain track situations. When two or more vehicles follow each other closely on the track, it’s called “drafting” or “slipstreaming.” This technique takes advantage of the lead car’s air flow, reducing aerodynamic drag for the cars behind.
Both terms are used to define the point where the car comes out to the edge of the track at the end of the corner.
When a tire locks up under braking, it can wear away tread leaving a flat spot. Flat spots aren’t only a problem for traction, they also produce excess vibration you can feel in the car.
A hairpin is a very sharp turn in a track. In technical terms, a hairpin turn will have an acute inner angle that will require the car to turn 180° or more to continue down the track.
The line is the pathway that is driven to minimize the overall amount of time it takes to complete a lap of a track, from the start/finish line and back to it again. The line through an individual corner is one that results in the fastest lap time around the entire track, and not just the fastest through that one single corner. There are ways to drive through a corner that will get you through it in less time than from driving a different line, but if it doesn’t help you tackle what comes after that corner (usually a straightaway), it often results in a slower overall lap time around the track.
With a positive caster, you will create a mechanical trail between the vertical point of contact between the tire and the ground and the steering axis of the wheel. More caster means a larger mechanical trail. The effect of a mechanical trail is increased torque on the steering system that will help to unwind and center the steering wheel during a turn.
Oversteer is when the rear tires have less traction than the front tires do, and the car turns more than you’d like — it’s loose, and has the effect of having the rear slide out and make the car almost spin out. Taken to an extreme, the car will spin. If you’ve ever played around in a snow-covered parking lot in a rear-wheel-drive car, you’ve likely experienced oversteer. But that was mostly “power oversteer,” where you kicked the rear-end of the car sideways by trouncing on the gas pedal, breaking traction at the rear tires, and causing those rear tires to have less grip than the front tires. This power oversteer is different, but similar, to regular oversteer that is mostly caused by how you’re driving and how your car handles.
A place on the track where you can make a pass, as it’s less risky to do so here. For example, a long straightaway is a good “passing zone,” as there is more room to position your car next to another. In most HPDE events, the organizers will designate allowed “passing zones” — these are the only areas on the track where passing is allowed.
Pitch is one of the three axes your car’s center of gravity can rotate around. An easy way to think of pitch is when the front of your car goes down, as it does when you brake hard, the back of your car will pitch up. If you accelerate quickly, the back will pitch down and the front will pitch up.
When a faster car is looking to pass you, you give it a “point-by” to tell the following driver which side you’d like to be passed on. In most HPDE events, point-bys are mandatory; a pass cannot be made unless there is a point-by. If you want the faster car to pass you on the left, you point to the left out your open driver’s side window; if you want it to pass on the right, you either put your arm out the window and point over the roof to the right, or point to the right inside your car. Keep in mind, though, the following driver sometimes cannot see your arm/hand in the car if there is glare on the rear window; this is why pointing out the window is more clear. Some HPDE events require drivers to use their turn signals rather than a hand signal. However, some events have you point-by the passing car by putting on the turn signal on the side you want to be passed on, while other events have you put on the turn signal on the side you’re going to stay on. Be sure to know the rules of the event you’re participating in.
Rake is a term that describes the angle the car chassis has to the ground from the front to the back. When the lowest point at the front of the car is lower than the lowest point at the rear, this is called positive rake. When the front is higher than the back, this is negative rake.
Everyone has heard a car salesman talk about a new model’s “smooth ride,” but what you may not know is that this is a fairly technical term. Ride (sometimes called heave) is the up and down movement of the entire chassis in relation to the tires. Ride is the response of the chassis to the car’s movement on the track and the forces acting on the tires and suspension.
Ride height is the measurement of the lowest point of the car chassis in relation to the ground. Ride height can be important if there is concern that the chassis could make contact with the ground.
Roll is another axis a car can rotate around, this time from side to side. Roll is the effect you experience where the force of taking a corner quickly has your passenger reaching for a strap or armrest to hang on. Not only occupants experience roll — the chassis of your car will roll in the opposite direction of a turn.
A skidpad (or skidpan) is a circular area flat pavement used to test a car’s handling, such as testing its lateral acceleration. Many tracks have a dedicated skidpad, but any flat pavement area that’s big enough will work.
A slick is special type of tire with a perfectly smooth tread used in some track situations. The reason slicks are used is grip. Our typical grooved tire tread only really offers an advantage on wet or loose ground. On a dry, solid track, a smooth tread provides a bigger contact patch for maximum traction.
Under cornering conditions there will be a difference between the direction a rolling wheel is pointed and the direction it is actually traveling. The difference between these two lines is called the “slip angle.” The forces a car undergoes during a turn means that all rubber tires will distort and have a slip angle on the track. Slip angle can cause the rear tires to have sideways motion during a fast turn, even without losing full traction.
The springs in your suspension require a certain amount of weight to compress them a certain distance. This number is called the spring rate. A higher spring rate means a stiffer spring; a lower rate means a spring has more give.
Braking with the tires at their limit, or threshold, of traction; any additional pressure on the brake pedal will either result in the activation of the Anti-lock Braking System (ABS), or a locked-up and skidding tire (in a car without ABS). Threshold braking results in stopping or slowing in the shortest distance (although some cars with super-high-end ABS can match it).
When someone refers to the throttle, you can substitute “gas pedal” for it, as they’re one and the same. The gas pedal is the throttle; the throttle is the gas pedal.
A person can stand with their toes pointing outward or inward, and so can a car, so to speak. This is called “toe” angle. The angle of the tires when viewed from above can either point inward (positive toe in), converging at some imaginary line in front of the car, or they can point outward (negative toe out), with the lines diverging.
As the name suggests, it’s where you initiate the turn into a corner. The point you turn in dictates much of what happens through the rest of the corner, which is why getting it right is so important.
The term for combining steering with braking is called “trail braking.” Trail braking at the entrance of a turn can optimize the entry path by reducing the radius and speed at the same time.
Understeer is when the front tires have less traction than the rear tires, and the car does not turn as much as you’d like — it pushes or ploughs on a larger radius than you’d like. In other words, it “understeers,” not turning or steering as much as you’d like. Another way to think about it is this: the rear tires are driving your car straight ahead; the front tires are trying to change its direction; the rear tires “win” — they drive the car straighter than you’d like.
This is the act of straightening the steering wheel as you exit a corner on a progressively larger radius. Your in-car instructor will often remind you to “unwind” coming out of a corner. This means straighten the steering (they are not telling you to relax, even though that might be a good suggestion!).
Every time you brake, corner or accelerate, you cause weight (or load) transfer from front to back or side to side. Weight transfer is tied closely to the three axes of your car’s center of gravity. When you apply the brakes, your car “nose dives” with the front pitching down. That’s because a percentage of the weight of your car has transferred forward, compressing the front suspension. It also puts more load or weight on the front tires. When you accelerate, weight transfers to the rear, causing the rear suspension to compress, and the back of your car to squat. When you go around a corner, weight rolls and yaws to the outside and back, causing the suspension on the outside of the turn (the left side tires when going around a right-hand corner) to compress.
Wheelspin is the name for a tire that begins to spin too fast because of the high amount of power applied. Wheelspin can negatively impact your acceleration.
Yaw is the third axis your car’s center of gravity can rotate around. Yaw rotation can be as simple as turning the car left or right. But there are also other forms of yaw. A car that is spinning out also experiencing changing yaw, even if it’s still sliding in a particular direction down the track.
It’s a lot of fun learning the motorsports terms as you get more and more into HPDE. You can help make HPDE more enjoyable by making sure your car will be insured for damages while it’s on the track. Most auto insurance policies limit coverage for HPDE. Here’s how to check yours.
If your insurance does have exclusions, not to worry. We offer HPDE Insurance to protect your car from damage when you’re participating in HPDE, track day or time trial events.