As with all types of cars, there is a lot of variation when you compare street models to their racing counterparts. Everything from the steering wheels to the materials used to make them are vastly different between the two. But just how different are the brakes?
The main differences between street car and race car brakes are the physical construction and the internal systems. Race car brakes withstand much higher temperatures, have highly sophisticated cooling systems and also have sensors to constantly monitor performance.
These differences all play key roles in making sure that the brakes installed in the car are suited to the driving style that will be used. Knowing these differences exist is important, but you should also consider why each difference is so important. So, let’s go into each one in more detail.
The Physical Construction
The basic purpose of a brake in any vehicle is to slow it down, usually in a controlled manner, and eventually to a stop. They do this by converting the kinetic energy – the energy possessed by the car while it is moving – into heat, via the friction caused by slowing the car down on the road surface. Sound can also be produced, such as when you make an emergency stop and hear the tires squeal.
The way that brakes do this usually involves something external gripping the wheels of the car. Strictly speaking it is actually the rotor or the axle, where there is usually a disc or drum brake installed. In most cars, there are disc brakes at the front and drum brakes at the back. What rubs against these discs or drums are the brake pads, which generate all of the friction.
The Power Of Hydraulics
In a normal car, when you press the brake pedal, hydraulic fluid amplifies you’re the pressure you apply to be able to clamp the brake pads against the brake discs with a strong enough force on all four wheels to slow the car to a stop. Although a fairly basic summary, this is the reason you can effortlessly press your brake pedal and slow your car from 60mph down to zero without hurting yourself.
One of the big differences that you will see in race car brakes is the use of two separate master cylinders. One of these operates the front brakes and one operates the rear brakes, and they allow you to have more control over the finer details of each set. This is known as brake biasing, and it is a vital component of race cars to give the driver more control and customization.
Other physical differences appear in the rotors, where both size and material can be drastically different between race cars and street cars. This is the part that turns the wheels, and it is connected to the drums or discs. Components such as the calipers and mounting brackets of the brake system will also usually be made of stronger but lighter materials in race cars.
The Brake Pads
The main difference when it comes to the physical construction lies in the brake pads used. Most road cars will use organic or metallic brake pads, which are strong enough for daily driving. Race cars, however, will often use ceramic or carbon brakes. These are much better at withstanding the ultra-high temperatures that come with all of the braking on a racetrack.
These physical differences are essential, as the type of driving that is done in a race car versus that of a street car is much more aggressive. Higher speeds and thus stronger braking means the materials used need to be strong and resistant to heat. So, in terms of the strength, they also need to be able to bear massive, repetitive braking loads.
The Technology Involved
Going back to the concept of the individual components and levels of customization, a lot of race cars have extra braking sensors and other pieces of technology that give the driver more data to work with and more control. In a racing situation, temperatures and levels of grip are vital, so all of these extra sensors ensure that everything is always working correctly.
Keeping Them Cool
Although technically a physical component of the braking system, ventilation and cooling systems within race car brakes are much more advanced than street car brakes as well. The optimum operating temperature of braking systems varies, but it is usually between 300-800oC. Outside of this temperature range, the brakes can crack due to thermal shock or cause excessive wear due to friction.
Much More Expensive
Each of these physical and technological differences obviously means that the braking systems in racing cars are much more cost and time-intensive. Building the systems takes time, and they are costly to repair. With advances in technology, those time and financial costs are being reduced. It is worth looking at a few motorsport examples to see where braking systems are taken to the extreme.
F1 Car Brakes
Very Durable Systems
The brakes on an F1 car have to withstand massive amounts of braking, with speeds regularly topping 200 mph then having to drop to less than 90 mph on the corners throughout the 300+ kilometer race. Modern F1 cars use carbon brake discs to provide maximum heat resistance along with maximum performance. Even then, regulations limit just how good they can be.
No Power Assistance
The main difference that you might notice between F1 and street car brakes is the lack of any power assistance. This means that all of the braking power has to come from the driver’s foot against the pedal, with 125 kg of force being required for maximum braking power. However, the force of the car slowing down does make it slightly easier to do this, but it is still harder than in a street car.
Another technological difference between F1 and street car brakes comes in the form of an Energy Recovery System, or ERS. This allows the car to regain some electrical energy from the kinetic energy that is lost when the car slows down. Although some modern cars do possess this system in one form or another, it is definitely not a universal feature.
Unusual Braking Habits
NASCAR brakes are another type of motorsport braking system that need to bear some extremely high loads. NASCAR generally involves less braking than F1, and on some tracks, such as the Daytona and Talladega speedways, the drivers will only ever use the brakes when coming into the pit lane and in the event of a Caution Flag. This is due to the lack of tight corners on these tracks.
Although these events are relatively rare in terms of the individual races, they can appear unpredictably. This means that the driver may have to slam on the brakes if a car up ahead crashes, and with little use in the lead up to these events, the brakes can rapidly crack due to the thermal shock. This means they need to be made from very heat resistant materials.
More Braking Than Accelerating
On the other hand, at tracks like Martinsville, the driver might end up using the brake more than the gas. This is because in NASCAR the drivers use the brakes as a tool for cornering, and thus can keep it pressed for 6 or 7 seconds when cornering. This again puts a lot of strain on the brakes throughout the race, with drivers going through two sets of discs each weekend.
Another interesting part of a NASCAR braking system is the fact that each circuit, and in fact each driver, will often require a different type of braking system. This is in part due to the way that the track is laid out as described above, but the calipers and other components will also be dependent on the track and the driver’s own personal braking style.
The brakes are one of the most important components of any car. They are what bring you to a controlled stop, and they save thousands of lives each year. Often overlooked, they are quite complex systems in street cars, and even more complex in racing cars. There are some key differences between the two, and there are even more differences between individual racing disciplines.
The main differences lie in the physical construction of the braking systems, with race cars usually involving more components and sensors than street cars. These also utilize more advanced technology, and stronger materials. The loads borne by a set of race car brakes exceed those of normal cars many times over, and thus the need to be resistant to heat damage and a lot of general wear.