Motor Sports - Racing Lines Explained

Unfortunately, this weekend is without an F1 race. To satisfy my weekly motorsport thirst I was thinking about racing lines and how they can vary from driver to driver. This is why in this article I want to talk about the different racing lines, explain the theoretical ideal racing line as well as talk about its variations. With that being said I want to mention that my drawn pictures might not be perfect but I think that they are able to picture the explanations better.

Ideal Racing Line

Let’s start with some basics, in case you are not very familiar with motorsport or racing. In theory there are several ways to take a corner. In the picture below we see three ways but there are certainly a ton more. In general, we want to take the corner as quickly as possible and not lose a lot of time in the process. This means that we want to keep as much velocity and also want to take the shortest way through this corner. So, let’s take a look at the different possibilities.

The bigger our radius the higher the velocity that we can take through the corner. This comes with the cost of the longest way trough this corner. As we can see in the blue line, our exit velocity will be probably very high but we also had to take the longest way around. On the complete opposite of the spectrum we have the red line. Here, we take the shortest way, but because the radius is very tight we are forced to have a very slow speed which results in us losing a lot of time. So what is the solution?

The green line shows us the theoretical compromise out of the two extremes. We are trying to take the corner as tight as possible but only touch it in one point, the apex. Other than that we are trying to maintain the highest velocity throughout the corner. This results in the green line, which starts out wide, takes the corner tight and exits it out wide again. In theory and without any competition, this line is promising to give us the best results on a single corner.

What is also important is the behavior of the driver during the corner. It is important to know the physics behind it. This means that we need to separate our corner in different sectors: the breaking sector, the steering sector and the acceleration sector. Before we even get to the corner we need to hit our needed speed to be able to drive the green radius. This means, before even thinking about changing the steering angle we need to slow down. This is done in the braking zone. After we are at the wished velocity we then start our steering process. It is important to keep our car under pressure so keeping the velocity is key here. We want the car to have a very similar change of forces and therefore no sudden changes of steering angle or acceleration is advised. Instead we need to have a steady and calm change of steering and approximately the same percentage of the throttle. Once passed the apex and are on the exit of the corner we can slowly decrease the steering angle and increase the throttle again, making it the acceleration sector. In this sector we should use the complete track in order to achieve the maximum velocity at the end.

Early & Late Apex

As mentioned before, the green line is the theoretical optimal route through the corner. But there are also other possibilities. For example the late and the early apex. Now I will tell you straight ahead, the early apex is something for racing drivers and is only advised to use on a race track. As you will need to be heavy on the brakes. This early apex line is the blue one in the picture below. We are having a lot of speed and will miss the corner completely if we are not heavy on the brakes during this process.

The exact opposite is the late Apex which is shown with the red line. In my opinion the late apex is a very mature way of driving, even in the normal streets. We have several advantages. First and foremost, it helps you to see into the corner before even hitting the apex. This means that if there would be something bad waiting around the corner you still would have the opportunity to change your trajectory. Second advantage is that we still have the main idea of an ideal line. We are steering very calmly and are not forcing our car into a state of discomfort whilst still being able to maintain a good speed throughout the corner.

Combination Of Curves

Everything what I said before would be a very boring race with just one corner. This is why racetracks have several of them! The important question is, how are we taking the corners in order to get the maximum speed and the best grip on the last corner which is connected to a long straight? In order to determine the correct path we need to go backwards through the sequence of corners.

In the following example we have a combination that has only the purpose of slowing the driver down. The most important thing is to get the perfect exit of the second corner and in many cases this means to not get the perfect line on the first corner. In this case the blue line is not exactly perfect but certainly better than the red line. In this case we even manage to take both corners of the chicane in a very good angle. In a lot of times this can not be the case and the first corner has to be sacrificed for the second one.

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Conclusion

I think that all in all it is very interesting to think about these little things that make this sport so amazing. One little mistakes can cost you so much time and therefore possible places. Set the braking point to late and you miss the corner, set it to early and you lose a lot of time. In one of my next articles I want also to talk about some racing physics, especially the Kamm’s Cricle, so stay tuned for that as well!

Published by ga38jem on
Sports Talk Social
On 6th June 2022