High performance braking. Why it matters!
High performance vehicles require brakes that are designed for the specific make and model. Think about it; top end vehicles drive very differently to smaller, ‘about-town’ cars – so it stands to reason that the demands on the braking system are different too.
Let’s start by explaining why…. when a vehicle decelerates, its brakes convert the vehicle’s kinetic energy into heat by friction. However, since kinetic energy rises with the square of velocity, stopping from the higher speeds associated with high performance vehicles, puts an exponentially increased demand on the braking system, generating significantly more heat. If not dissipated effectively, this heat builds up, reducing the brakes effectiveness and causing what is known as brake fade - one of the biggest challenges for high performance vehicles. For this very reason, it’s important to only ever fit high quality parts that can handle these extra demands.
Brake pads, for example, are designed to work within an optimal temperature range. Anything above this, and the resins and materials in the friction lining will start to break down, creating a film of gas between the pad and disc which interferes with braking. The best way to prevent this, is to choose a pad that has been designed specifically for high performance braking systems; one with a high and stable friction coefficient, yet which can also handle the higher operating temperatures. That’s why we carefully select our friction material, using a precise blend of more than 130 different friction ingredients to create the right pad for the vehicle. Some aftermarket brands use only one or two formulations, resulting in an inevitable compromise in performance.
Excessive heat can also have a detrimental effect on a vehicle’s brake discs. At high temperatures, the brake pads can transfer a thin layer of material onto the surface of the brake disc or brake rotor. Whilst this is beneficial during bedding in, ongoing it can negatively impact stopping power. Worse still, as the pads rub on the now-glazed surface, they can create uneven heat build-up across the disc. If the temperature in these areas exceeds 650°C, the cast iron changes structurally and transforms into a hard material called cementite, creating high spots which can lead to brake judder and premature disc wear.
Providing a means for this thermal energy to escape is therefore critical, and is why leading manufacturers like Delphi Technologies, offer a number of different cooling technologies. Take our vented discs as an example. By continually moving air across the disc’s surface or through the disc itself, the special internal cooling passages allow more heat to be dissipated, improving both cooling capacity and resistance to cracking from thermal shock. Similarly, the special axial holes in our crossed drilled discs help to dissipate heat, brake dust and gases, keeping the brake pad surface both cool and clean and reducing the risk of thermal distortion, warping and brake fade.
Another heat affected part, is brake fluid. If brake fluid boils and becomes a gas, through prolonged or higher speed braking, it will lose its ability to transmit force. At first the brake pedal will simply feel spongy, however as the fluid boils, it will travel all the way to the floor, potentially disabling the brakes. To make matters worse, as the water content in the fluid increases with age, the temperature it boils at decreases. Choosing a fluid with a high boiling point is therefore critical. Our DOT 5.1 has been specially formulated to deliver a high boiling point for guaranteed high performance braking.
So, the next time your servicing brakes on a high performance vehicle, choose only higher grade parts, like Delphi Technologies, engineered for the vehicle and the extra demands that come with it.