6 things no one ever told you about NASCAR Cup Series brakes

11/17/2017

 At this point of the season, everything has been written and said about NASCAR cars and drivers.

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But what nobody has probably told you about yet is the NASCAR brakes and why they are so important. At this point, we at Brembo will step in with our vast experience in the NASCAR championship as braking system supplier.

Here are six things that no one has ever told you about NASCAR Cup Series brakes. ​


 

​1) NASCAR brake discs also perform an aerodynamic function

Besides slowing down the cars so they do not fly off the track, NASCAR braking systems also improve acceleration and tackling curves in the best possible way. In fact, the brakes are an integral part of the car setup, as these 3 cases demonstrate:

 a) As a whole, braking systems are unsprung weight that impedes movement of the car: the higher the weight of the unsprung weight, the lower the acceleration and top speed will be. The use of lighter calipers and discs that have limited residual torque, whenever possible, therefore improves downforce and consequently acceleration.

b) The discs (which must be cast iron in compliance with the rules) can have very different ventilation channels: the ventilation channels on Brembo brake discs tend to be larger on Short Tracks because the temperature must be dissipated more quickly. In fact, NASCAR discs reach a temperature of 1,800°F while Brembo HTC 64T brake fluid has a boiling point of 635° F. However, Brembo brake disc ventilation channels are more contained on Road Courses and even smaller on Intermediate tracks and Super Speedways.

c) The braking system is also used to change tire temperature: on some Short Tracks, the brakes are stressed for a long time and the lack of a Caution Flag and therefore, no slowing down, can lead to a dangerous rise in tire temperature with a consequent risk of the bead breaking. The use of discs with efficient cooling developed specifically by Brembo minimizes this risk.

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2) On Short Tracks, the drivers use the brake more than the gas

On Short Tracks, the brakes are used not only to slow down, but also to help the cars turn.
Different use of the brakes allows the driver to set up his line more or less quickly.
Throughout the turn, the brakes therefore remain in operation. Consequently, on tracks like Martinsville, the brakes are used for about 6-7 seconds on each of the two turns.
This means that the drivers actually end up using the brakes more than the gas.

On Road Courses, on the other hand, the force of each individual braking operation is harder (the maximum load on the brake pedal reaches 176.4 lbs and maximum deceleration reaches 2.7 g) but the long straights let the systems cool, so much that the brakes are used for about 30 percent of the entire race time.

 

 
 

3) On Super Speedways, the drivers heat up the brakes a couple of corners before coming into pit lane

On the Talladega and Daytona tracks, the drivers never use the brakes except in the case of a Caution Flag and when coming into pit lane.
Caution Flag episodes are not predictable, so they can result in violent braking with cold systems that risk damaging the braking systems.
In order to prevent thermal shock when stopping on pit lane, especially after a few laps when the system has not been used, most drivers rest a foot on the pedal at the beginning of the last lap before making a pit stop. By doing this, the disc begins to heat up, preparing itself for the subsequent force.


 

4) Drivers with the same car may use different braking systems

People tend to think that all the drivers who drive the same car have the same technical material.
In reality, with the exception of the engine and the car, each driver can use different components than his counterparts.
Even from the same braking system supplier, the drivers can opt for discs with different geometries and pads of different thickness and with different ventilation.
In fact, everyone has their own braking style that has an impact on the wear and heating of the systems: some drivers use a style typical of single-seater race cars, with heavy initial braking and a progressive release of the pedal.
Others, on the other hand, begin to brake slowly and stretch the operation out for a longer amount of time.

 

 
 

5) Each type of oval requires a specific braking system

In the Nascar Cup Series, the 3 types of ovals require just as many varieties of Brembo brake calipers because the use of the brakes is different.
On the Super Speedways (2.5 mile ovals) the brakes are never used except to enter pit lane or in the event of a yellow flag. On Intermediate tracks (1 to 2.5 mile tracks) the brakes are used very sparingly, whereas on Short Tracks the braking system is used throughout the entire turn.
Consequently, on Super Speedways, smaller Brembo brake calipers are used, on Short Tracks larger ones are used and on Intermediate tracks a medium size is used.
Furthermore, while in Formula 1 the size of the discs used are the same throughout the year and only the ventilation channels change, in NASCAR the diameter and thickness of the front discs changes depending on the type of circuit.


 

6) Every weekend each car uses two sets of discs

Wear is not a problem for NASCAR teams: in fact, after using the first set of discs for free practice and qualifying, they are replaced with new ones to tackle the race.
Therefore, on average each disc is used for a maximum of 600 miles. Each caliper, on the other hand, can be used for several races, but not in a row. In fact, in order to get to the tracks in time, each team makes at least a dozen of each car.
This means that the same car rarely races 2 weeks in a row. Also, after each use, the calipers are disassembled and the parts subject to wear are replaced.

 

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