Lesson One - Goals, What We Are Trying To Achieve
Lesson One – Goals: What We Trying To Achieve
The Race Car Technology – Level One Course is designed to introduce the student to the parts and pieces of a race car. We will explain what the systems are, what they are used for, and how these systems work with the other components on the race car.
NOTE: We will be primarily working with circle track race cars, and the late models with fabricated chassis. That is not to say much, if not most, of the information presented will apply to most race cars. Some of the information will apply to every race car. But, the numbers of circle track race cars around the US and in other parts of the world are larger than any other form of motor sports.
Many of the
systems are common among various race car types and uses. Once you have
completed Level One, you will know what the systems are, and what to call the
parts used to make up the systems. This is an important and necessary course
leading into our RCT Level Two Course, which takes us to the actual setting up
of the race car.
Before we get into the nuts and bolts of race car technology, we need to fully understand what our goals are for this school and exactly what we are trying to achieve in RCT Level One. For every racer, no matter what class, type, sanction or level of expertise, the goal is simply to win races. To win races you need to be faster than any of the other competitors. To be faster, you need knowledge. We are going to give you some important knowledge.
The beginning of knowledge, someone once said, is the admitting that you don’t know. Not knowing says you do know there is knowledge out there that you have not yet been introduced to. Being open to this philosophy helps you to seek and gain knowledge throughout your journey in life.
For any student to proceed through a course, you need to be aware of and understand the words that are going to be used in the process, and the meaning of those terms. You can always refer to the Glossary if you forget or need to remind yourself.
The race engineer’s goals are very simple in concept, but more complicated to carry out. On any race course, be it with circle track or road racing, on a dirt or asphalt surface, there are key areas of performance where your car needs to be made better than any of your competition and those are the following;
The goals for designing our race cars are basically the same be it a formula road racing car or a late model circle track car. Performance gains in the slower portions of the track cause all of the speeds to increase around the track including on the straights.
Maximizing Grip - When non-chassis elements like powerplants are more or less equal, grip is what will help you win races and championships. Motors accelerate you, brakes slow you, but grip makes you faster through the slower turn portions of the track and relatively small gains in lateral grip will produce huge gains in speed and performance.
What are the Key elements of grip? The tire contact patch is where grip is produced. Causing the tire contact patch to be larger increases grip and causing the most vertical loading on that tire contact patch is the other key ingredient for maximizing grip.
Maximizing the amount of traction that is available from the four tires on a race car, any race car, will make you as fast as you can be, all other things being equal. Everything we present in RCT will ultimately lead to optimization of the race cars grip and the use of that grip to go faster.
What are the basic parts that make up Grip?
● Loading On The Tire – The more load we can put on a tire, the more Grip that tire will have, period. But, this gain in grip is not linear as we will explain later on. Load can come from the weight of the car, mechanical downforce from banking, and aerodynamic downforce, all of which will be explained in detail later on.
● Contact Patch Area – The greater the size of the contact patch, the more grip. If we can find ways to make the tire contact patch larger, then that tire will produce more grip.
● Tire Compound – The physical and chemical makeup of the tire can provide more grip. The softer the material, the more grip within limits. We have rules that govern the softness of the tires, but we need to stay very close to those limits.
● Load Distribution – A pair of tires on the same end of the car, or same axle, will produce more grip when they are more equally loaded. The most grip from a pair of opposing tires will come when they are equally loaded. There is a variation to this concept for dirt racing that will be addressed later on.
● Angle of Attack – What is called Angle of Attack, or Slip Angle, is when a tire is pointed slightly to the inside of the arc it is following through a turn. If a tire were to follow the exact tangent line around a curve or arc of the turn, it would not generate any side force to counter the centrifugal force.
So, in consideration of the other items that make up grip, it is fair to say that none of those would be useful if it weren’t for the creation of Angle of Attack. No matter what amount of Loading or size of the Contact Patch area, or how soft the tire compound is, or how equal the load distribution between opposing tires, the car would not stay on the course without the tires developing an Angle of Attack.
So, there you have it. Those five things represent the parts that help make the grip we seek to make us faster so we can win races.
As we go through each part of the race car in the other Lessons, we will explain how to optimize of those parts to enhance our grip and make us faster through the slow speed turns. And we will understand how that will in-turn make our whole lap faster at every point around the course.
Why Does More Grip Make Us Faster? When a race car turns, a lateral force called Centrifugal Force tries to push the car to the outside of the turn. The tire contact patches resist this force. The speed we can drive through the turn is limited by the amount of grip we have in our tires. The more grip, the faster we can drive through the turns.
The one often overlooked benefit of achieving faster turn speeds is this: the faster you exit a slow speed turn, the higher the speed at which you will start accelerating down the straight part of the track in-between the turns.
So, speed gained in the slow speed turns will be carried down the straights too. It’s not just that we gain speed in the slow speed turns with more grip, we gain everywhere around a race track.
To give you an example, on a typical or average length Formula One track, one tenth of a second is about 17 feet on the race track. Some teams are a full second slower per lap than the fastest teams. That is 170 feet per lap that the faster cars move ahead of the slower cars each lap. In a fifty lap race, that equals 1.6 miles, or 2.5 kilometers.
We often think of the formula one cars as being the ultimate race cars and perfect in every way. If that were so, then there wouldn’t be a two second gap between the fastest and slowest cars. There must be a difference in designs that causes that huge gap in speeds. We like to think it is lack of mechanical grip that makes not only the slow turns faster, but the entire lap.
We already know that some teams get lapped in a F1 race, and the average length of those tracks is around 3 miles. So, those lapped cars are on average 2.0 seconds per lap slower than the winning team. And they all run with the same choice of tires. That is hard to fathom.
Is the gain realized by the winning F1 teams all grip? No, as we have read, some engine packages are down on horsepower and that is a factor in the difference in lap times. But what about the teams who have the same engine package as the winners? Why are they so slow? It could be that they lack mechanical grip in the slower portions of the race track.
Building mechanical grip is one of the most important areas of race car engineering, even over and above aerodynamic grip. The reason is this; To gain maximum aero grip, you must have high speeds and the most gains from mechanical grip happen in the slower turns where the speeds and the aero downforce is lower for all of the teams. So, the only thing we can point to as the reason for the gain in performance for the winning teams is Mechanical Grip.
The Concept Of Mechanical Balance - If your car has more overall grip than other cars early in the race, that grip might not stay superior and you might end up being a slower car through the turns later in the race. This is due to the Balance Factor. There are two definitions of balance. They are not the same and they cannot be confused. One is handling balance which is defined as a car that is neither pushing (understeering) or loose (oversteering). Pushing is when the front set of tires has less grip than the rear set of tires. Loose is the opposite.
The Mechanical Balance concept is simple. We want both ends of the car to work in sync so that one does not try to cause the other to do what it does not want to do. When the two ends of the car are working in unison, we can achieve the goal of mechanical balance.
A team can attain handling balance fairly easily, but just the fact that the car is neutral in handling doesn’t translate to speed or consistency. A car can have less overall grip than other cars and still be neutral in handling. Although a neutral handling car is a goal, it is not the first and primary goal and not what we are discussing here.
The other balance is Mechanical Balance. Simply put, this is when the two suspension systems, front and rear, are working in sync and where the load transfer is predictable and maximized. This is what teams need to search for. The end result of all we do with chassis engineering must be towards the goal of Mechanical Balance.
Circle track race cars are complicated, but much easier to setup that a road racing car. This is because the setup in a circle track car can be asymmetrical, meaning the spring rates, cambers, etc. from side to side can be different. The circle track car is only turning in one direction and so the setup need only be correct for that direction of turning.
The Search and Desire for Mechanical Balance should be the foremost goal for every race engineer. A lot of good things come with achieving MB. The tires do not work as hard and will last longer. The car is much easier to drive. The car maintains higher turn speeds as the tires wear later in the race, or later in each stint for cars that are allowed to pit and take on new tires.
So, to reiterate what we have covered so far, our goals for this course are to gain knowledge, understand the terminology, and to learn how to setup a race car to maximize grip in a way that utilizes a Mechanical Balanced state. In the Lessons to come, we will be presenting information you will need to understand and apply principles that will help achieve these two important goals.
And we are not leaving aerodynamic downforce out of the discussion, we just need to separate the mechanical grip from Aerodynamic enhanced grip. We need to do this because, many times in the search for the maximum aero properties, a team might deviate from the goal to achieve a Mechanical Balance. We think you can have the best of both worlds.
So, those are the goals for us in RCT Level One, now let's get started with our education. As you progress through the next series of Lessons, keep in mind that each Lesson builds upon the previous Lesson. There is valuable information in each and every Lesson, even for the more experienced racer. Please read, and re-read each of the Lessons carefully.