Technical Series Part 1: Factors affecting the Handling, Balance and Tire sensitivity of an F1 car

In Part 1 of this series, we will look at two important and popular terms used frequently by the team and drivers during a race weekend. These terms are so common these day’s during driver

In Part 1 of this series, we will look at two important and popular terms used frequently by the team and drivers during a race weekend. These terms are so common these day’s during driver interviews that many a time, it feels a bit orchestrated or even worse, seems as though drivers give excuses for their own poor performance. However, a deeper look into these two topics reveal the complexities involved and why these factors are so important for a driver to eke out the best from the car either during qualifying or race day.

Handling, Balance, and Tires have historically affected the performance of even the fastest cars and have played a major role in deciding the competitiveness of many F1 seasons. There are simply too many aspects that dictate the handling, balance and tire performance which we will discuss in future parts of this series, but we will start with the absolute basic concepts.

To understand better, we need to deep dive into a few basic elements that play major roles in these two issues:

Handling and Balance:

Car handling and balance are dictated by a number of factors and here we will look at how a basic design consideration can have a drastic impact (positive or negative) on the handling and balance of the car. Of course, this is a very basic design principle that teams will be more than competent enough to tackle, but nevertheless is the base starting point of a good racing car design. And for us as fans who don’t get to see the internal’s of a car and the packaging, it is vital to know why a particular car might be struggling to achieve peak performance and drivability.

Below image gives insights into various critical parameters that govern the design of a modern Formula 1 car.

Center of Mass (COM) is the point where all the mass of a car is thought to be concentrated. Think about all the components that contribute to the weight of a car: Driver, Engine, Gearbox, Chassis, Seat, etc. It is critical for a designer to understand the precise lateral location at which the COM exists because this helps him to define the optimum weight distribution between front and rear wheels.

Also, in order to control the degree of roll introduced in a car during cornering and keep a limit on the weight transfer introduced during acceleration and braking, the longitudinal position of the COM is extremely critical.

The eventual goal has to be that the COM not only affects the balance of the car in a positive manner but also enables tires to perform at an optimum level by providing sufficient grip through the tire contact patch.

Remember that the entire balance of the car is dependent on the COM. This is exaggerated in today’s racing since refueling is banned. This means that as the race progresses, the fuel levels in the car change (the car gets lighter) which in turn affect the COM. Hence the location of the fuel tank is ideally kept as close to the COM to negate the effect of decreasing fuel levels.

It is fairly easy to understand now as to why it becomes so difficult for a team to drastically improve its performance of the car or its drivability over the course of a season. Primarily due to the fact that it has an inherently unbalanced or a poorly designed car (not aerodynamically). We hear drivers and team principles talking about “fundamental issues” with a car. This would mean that right from defining the basics such as COM’s, the car’s development has gone into a wrong direction. This makes is difficult to correct over the course of 21 races. Quite often, the correlation of the development data with actual road test fails to give the desired increase in performance. And hence expecting teams to address performance gaps within a few races with periodic updates is an unrealistic expectation to have.

Tire Sensitivity and performance:

When the vertical load on the wheel is increased, the grip increases but at a progressively slower rate. This phenomenon is known as “Tire Sensitivity”. After a while, once the grip level reaches its peak (which means the tire is giving the highest possible grip level for that compound), it starts to fall down gradually (sometimes too quick for a teams/drivers liking). This phenomenon is called as “Overloading”.

What we see from the below graph is that, as the load on the tire increases, the amount of grip provided by the tire also increases gradually. This condition is true until the point of overloading when the tire no longer can take an increase in load that helps in tire grip. This increase in load is now detrimental to the amount of grip it can provide. The setup of the car, its tire sensitivity and driving style of a particular driver heavily dictates how soon the tires run out of maximum grip.

That is why we hear many drivers complaining over the radio that tires are losing grip after a few laps in a race due to setup issues. Every tire has a performance window during which it provides the maximum possible grip and teams can dictate how long that performance window will last by setting up or designing a car that can eke out the most from a set of tires. For this, the load management on all tires is a critical factor.

In order to achieve the best handling and balanced car, individual vertical wheel loads (on all 4 wheels) need to be assessed. This is vital to determine the loads that will be exerted onto the chassis, brakes, suspension members, transmission and other components on a car. Every race we hear drivers describing that “the balance wasn’t there” which in turn affected the drivability, or “the handling wasn’t perfect” which stopped them from achieving the limit of the car. And the setup affecting the individual vertical wheel loads play a major role in determining if a car is going to have excellent handling and balance. We will look at these aspects in later parts of this series.

References:

Race-Car-Design-by-Derek-Seward

3 thoughts on “Technical Series Part 1: Factors affecting the Handling, Balance and Tire sensitivity of an F1 car

  1. I do agree with all the ideas you’ve introduced to your post.
    They are very convincing and will definitely work.
    Nonetheless, the posts are too short for novices. May you please lengthen them
    a little from next time? Thanks for the post.

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