For HPDE/track day enthusiasts this is basic instruction, and these driving concepts become second nature. However, for most first time participants and novices, track day terminology and concepts are foreign.
We suggest that you bypass the distracting on track terminology briefs, and go in to the HPDE armed with some basic concepts, definitions and knowledge.
No matter if you're a first-timer, novice, or experienced track enthusiast, entering as many of these into your lexicon as possible will help you get the most out of a track day, and potentially permit you to help others do the same.
The ideal point at which a corner is "clipped" by the inside wheel(s). Apex points vary widely according to the type of turn, radius, speed involved, elevations, and other factors. Hitting the correct apex point allows for both maximum speed and momentum through the turn, as well as the proper vehicle angle on corner exit.
The apex point not always just simply the very middle of the turn, as is sometimes assumed.
THE BLEND LINE
A solid line that indicates where cars exiting the pits are supposed to rejoin the track. Think of the blend line as a single vehicle lane exiting the pits. When the line terminates, cars are free to rejoin the track with discretion.
(Also, the name of this here blog…)
The point at which brakes are first applied and speed scrubbed in preparation for a corner.
The phase of cornering that occurs after braking and before the apex.
The point at which a driver first gives steering input into a corner.
The act of recovering from oversteer (slide). The driver gives steering wheel input toward the direction of the slide. Also called countersteering. Here's an unintended example…
Also sometimes called "lifting off" by HPDE instructors. In most instances, the need is not to go from 100% throttle to 0%, but rather to reduce power by 25%, 50%, or whatever the circumstances dictate. Breathing the throttle is customary to permit a faster car to pass during an HPDE.
MAINTAINING THE THROTTLE
Maintaining constant and steady pressure on the throttle through a turn or turns. Often used to keep a desired speed and the car settled through a corner, or series of corners.
Occurs when the rear tires exceed the lateral traction limitation under cornering, and the back end of the car begins to slide or step out. Oversteer can occur during corner entry, mid-corner, and on corner exit. Some slip angle/oversteer can be advantageous mid-corner to permit the car to rotate, and also on corner exit; also called "power oversteer."
THE RACING LINE
The absolute most efficient and fastest route around a racetrack.
WET RACING LINE (OR "WET LINE")
When track conditions are wet, the racing line shifts; particularly if the track is "rubbered in," i.e. there's a layer of tire rubber on the racing line.
A general rule is that the wet racing line is one car width off of the racing line. Staying on a rubbered in racing line when conditions are wet is akin to driving on ice. Can be fun... but never fast.
TIRE CONTACT PATCH
The part of the tire that is in contact with the pavement at any given time. HPDE/track day enthusiasts often look to increase the tire contact patch with track tires.
> contact patch = > grip.
TRACK REFERENCE POINTS
Reference points on and around the track that help the driver navigate. Everything from pavement irregularities, to trees and buildings around the perimeter of the track can serve as reference points to help the driver be in the right place at the right time.
TRANSFERRING OR SHIFTING LOAD
As the car corners, brakes, and accelerates the weight or load of the vehicle is transferred accordingly. For example, under braking the front end and tires bear the most load pressure/force. Under acceleration, the rear end and tires bear the most load pressure/force, etc.
THROTTLE APPLICATION POINT
The point at which throttle is re-applied during cornering, and as the car heads toward corner exit.
The act of varying the pressure on the throttle in an effort to both maximize speed and/or maintain control. Modulating the throttle is often necessary during oversteer recovery/correction, for example.
The act of letting momentum carry the car to the far side of the track on corner exit. If a corner is taken optimally, then tracking out occurs "naturally" due to the speed and angle involved. However, the racing line does not necessarily include tracking out after every corner. For example, the driver would not track out if the setup up for the next corner occurs immediately, and tracking out puts the car out of position for the subsequent turn-in point.
The act of maintaining some brake pressure after the initial brake point and as the car is turned in toward apex. Trail-braking while giving steering input increases the vehicle's turn in grip.
Trail-braking also permits more speed to be carried into the corner as compared to a cornering strategy where the car isn't turned in until it has been slowed completely to corner apex speed.
Occurs when the speed/momentum into a corner is too great, and front tire grip is insufficient to turn in at the intended angle. Instead of the front end gripping and turning in according to steering input, the car "pushes" through the turn. Understeer is almost always undesirable, and puts the car off of the racing line.