F1 car technologies. Part 2 of 5 – Brakes

Part 2 of my Formula 1 technical series looks at the brakes of a Formula 1 car.

The brakes on a Formula 1 car work on exactly the same principal that your road car tyres do. The brake pedal pressurizes hydraulic brake fluid in the master cylinders, which then in turn move pistons inside the callipers, which then move brake pads, which then clamp against the discs.

Formula 1 regulations state that no mechanical or electrical assistance is allowed. This means no pump can be used to pressurize the fluid, even the servo that you get on your road car which multiplies the effort put in by the driver, is banned. This means that to stop an F1 car fast enough to set a quick lap time the driver has to put in a pedal pressure of around 75kg, or more depending on the driver.

The brakes on a Formula 1 are of the Carbon-Carbon design. Carbon discs and pads are used as they withstand heat and wear much better than ordinary steel or iron discs that are found on your road cars.

ABS is also banned.

Just like the brakes on your road car, a Formula 1 car has two, separate braking circuits. Unlike the road cars they are split front-to-rear rather than diagonally across the car (front left+rear right, rear left+front right)This allows the brake bias between the front and rear of the car to be changed to suit each different corner or braking zone on the track. This means that one aspect of the car setup can be changed constantly throughout the race. With the advent of KERS, the brake bias has to be more forward due to the added braking at the back of the car. Having more forward brake bias increases understeer on turn in to a corner, but increases stability. On the downside it’s not good for front tyre preservation as added heat radiates into the tyre which can cause it to overheat, and also an increased chance of front tyre locking which increases tyre wear and also creates flat spots. Flat spots can be a very big problem. The video link at the bottom of this article is one case of a serious flat spot problem! In the first few seconds of the video you can see the tyre vibrating massively and then as soon as Kimi hits the brakes, the added load with the vibration causes a massive suspension failure.

The brake bias adjuster must be a mechanical adjuster, and the one found on the RedBull RB6 was of the ratchet and lever type. This means that a small lever, sitting on a ratchet disc moves a linkage bar which in turn moves a small balance bar around a pivot on the master cylinder. This controls the amount of pressure acts on the fluid in each of the two master cylinders.

The discs on an F1 car must be a maximum of 28mm thick, and 278mm in diameter. They are made with ventilation passages through them to keep them as cool as possible, yet they still run at around 1000°C. The callipers are made out of Aluminium-Lithium alloy as it radiates heat better, and also because the materials that they’re made out of must be of a specific strength (80gPa) They must also have a maximum of 6 pistons per calliper, and one calliper per wheel. Each calliper must only be attached to the car by a maximum of 2 bolts.

Each single brake is fitted with two sensors. These are temperature, and wear level sensors. The temperature sensors are infra-red type, and are mounted on the side of the wheel hubs (upright). They detect the amount of infra-red radiation coming off of each disc to measure the temperature.

The wear sensors are of the LVDT type (Linear Variable Differential Transformer). They are mounted in the callipers and measure the movement of each brake pad. The discs and pads are made of the same material so wear evenly. As the components wear, they have to move further and this is picked up by the sensor.



One comment

  1. Pingback: F1 Technical series. Part 3 – Suspension « pptf1car

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