F1 Braking Systems

Formula one cars can come to a stop from 100 kilometers an hour in about 15 meters which is almost a quarter of the braking distance of your average Road car they can go from 300 kilometers an hour to a complete stop in under four seconds pulling up to six G of deceleration force with such high speeds and tough corners f1 cars need to be able to produce massive braking forces not just for performance but for safety as well a driver needs to know the car will respond when they press the brake pedal and not cream it into a wall or the back of a competitor let's look at the braking system an f1 car as a whole before we dive into the individual components when the driver hits the brake pedal it transmits a force to two master cylinders one cylinder controls rear braking and the other front braking let's focus on the front braking to start with as it's much simpler the master cylinder acts on brake calipers which squeeze brake pads onto brake discs this hard friction between the brake pads and the discs slows the car down now let's take a closer look at those components then these master cylinders are filled with brake fluid just a couple of hundred millilitres worth the fluid fills the brake lines that runs from these cylinders to the brake calipers acting as the arteries of the braking system now fluid is incompressible so when the pedal is pressed and the plunger is pushed into the cylinder the fluid immediately put forces on the other end of the brake line this is how hydraulic systems work the brake calipers are like clam shells around the brake discs and house brake pads within each side of the shell the hydraulics feed into Pistons no more than six within the calipers and these Pistons push the brake pads into the brake discs as the brake discs are attached to and spin with the wheels when the pads clamp on to the wheels the frictional force between them will slow the spinning of the wheel and ultimately the speed of the car the calipers themselves are often mounted low on the discs to keep center of mass low but tend to be placed closer to the 5 or 7 o'clock position rather than the lowest six o'clock position this is partly because the bleed nipple needs to be fairly high a bleed nipple you asked with horror in your eyes well remember when I said fluid was incompressible and that was what allowed pedal force to instantly translate to the brakes well sometimes air bubbles can get into the hydraulics and gas is compressible so when the brake pedal is pushed with gas in the system the gas can deform reducing the braking force at the other end to flush this gas out you can open the nipple and as it's placed high up the gas will rise more readily to the top and be flow out when you force fluid into the system you'll often bleed the system between sessions just to be on the safe side onto the actual brake pad and disks then the brake discs can be no larger than 270 millimeters in diameter or 32 millimeters thick a larger diameter means greater stopping power as it's easier to stop a spinning disks by grabbing it further from the pivot point then closer to the center the restriction of the rules in this area is to limit braking power of the car so braking zones can remain somewhat competitive unlike steel type brakes on modern road cars f1 brakes are made of a special carbon composite called hilariously carbon carbon it's called this because it's two types of carbon composited together a carbon lattice like graphite that's reinforced with carbon fiber carbon carbon is strong and can withstand very high temperatures and has a very high coefficient of friction now the coefficient of friction of a material just tells you how well a material grips when rubbing against another material ice being slidy has low coefficient of friction rubber being not sliding at all has a high coefficient of friction carbon-carbon also has very low thermal expansion and low thermal shock meaning it won't deform or crack suddenly under high temperatures this ability to stay robust under high temperatures is extremely important see the way brakes slow tires down is by converting energy the kinetic or moving energy of the spinning wheels is converted by the brakes into heat energy as the brake pads grip the disk the high frictional forces turns the energy of the wheel into tremendous amounts of heat a cold brake can heat up by as much as a hundred degrees every tenth of a second in the initial phase of braking carbon brakes work optimally between 400 and 800 degrees Celsius though heavy braking can often push brakes to a thousand or 1,200 degrees Celsius now brakes being overly hot causes two real problems one if the brake is already hot then it has less ability to absorb heat and therefore take energy from the wheels if under braking the brake disc can rise from three hundred to a thousand degrees it's acting as much more of an energy pump than if it could only move from eight hundred to a thousand degrees Celsius to the main driver of brake where is thermal degradation which is where due to temperature at high temperature the carbon will readily oxidized which is essentially burning at the surface layers in excessive wear or prolonged overheating the carbon deeper within the breaks can oxidize and weaken the structural integrity of the brakes which is why worn-out brakes start to disintegrate to dust in worst cases the brakes can simply explode so the temperatures of the brakes need to be carefully managed if they're going to last a race distance and as fluid cooling is banned the engineers use good old-fashioned air cooling to solve this problem and the premise of air cooling is very simple and exactly the same as using a fan to cool yourself off on a hot day by using a stream of fast flowing air heat will transfer from a hot surface to the air molecules passing by which will carry this heat away from the hot body as a car moves quickly through the air the brake ducts channels some of the cooler air stream into the brakes to do this job to further improve air cooling the brake discs themselves are ventilated narrow channels run through the brake disc from the center to its circumference as the brake disc spins cool air is forced from the center out through the brakes and away from the system carrying brake heat away downstream over the years these channels have reduced in size increased in number providing greater overall volume for channeling air now larger brake ducts can be more of an aerodynamic drag but the difference in top speed between using larger brake discs and smaller versions are only a couple of kilometers an hour a greater reason for adjusting the size of the brake ducts is more to do with the braking nature of the circuit if you're having to brake frequently and/or heavily the brakes will need more intensive cooling as you aren't coming off the brakes as often and giving them enough time to lose their temperature you don't want to keep heading into braking zones with the brakes at 800 degrees so large brake ducts will more intensively call the brakes in the periods between the braking zones on the other hand the brakes don't actually work very well whenever a cold you ideally want them in at least 400 degrees when you hit the brakes if you're not braking very often on a circuit so there are a long periods of time between braking zones for the brake temps to come back down you're probably off a smaller brake duct so they don't lose too much temperature when you hit the brakes at cold temperatures the brakes can take a few hundreds or even tenths of a second to kick in properly which isn't ideal the other interesting problem to manage is that of feeding the thermal degradation problem as I said high temperatures the carbon oxidizes this means the carbon at bond with oxygen atoms in the air forming carbon monoxide or carbon dioxide now the brakes take a while to cool down and all the time they're at this high temperature they're still ripe for oxidation and all this while the brake ducts are feeding the carbon more and more air which includes oxygen and this can accelerate the problem tricky you'll often see engineers blanking off brake ducts with aptly duct tape if the ducts seem to be feeding too much air into the brakes either temperature or degradation wise so that's simple under the braking system the front brakes are powered by a simple straightforward hydraulic system the rear end is more complicated since the hybrid power unit was introduced the mg UK is a significant part of the system that slows down the rear wheels this Duty is now shared between the brakes and the mg UK to manage this effectively the rear brakes are not operated by a simple hydraulic system but by brake by wire a brake by wire system sometimes obliviously referred to as bbw means the physical action of the brake pedal is not directly attached the physical action of the brake callipers instead there's a computer in between telling the brakes what to do the mg UK can take up to two mega joules of energy from the rear wheels lap how much energy the mg UK harvests under braking at any given time is decided by things like brake pedal pressure harvesting settings and battery level the rest of the deceleration is performed by the actual brakes now the electronic control unit or ECU is fed live information constantly calculating and delivering exactly how much work the physical breaks and the mg UK perform in decelerating the car when the brake pedal is pushed any excess hydraulic pressure not used to brake the car is automatically fed back into the system via a release valve and this all happens on the fly and is incredibly sophisticated and while all this is going on it has to feel like real breaking to the driver now because the rear brakes don't have to do as much work as they are sharing the load with the mg UK the brake discs themselves are lot smaller than they previously were but if there's a failure of the mg UK and brake by wire system the rear brakes will have to do all the work and this is suddenly a massive problem larger discs can manage and dissipate heat much more affect even small discs which overheat very quickly this happened to Ricardo Monaco after his mg UK failure so he had to move the brake bias forwards to take the load off the rear brakes brake bias or brake balance sets how the braking force is shared between the front and rear brakes when the pedal is pushed ideally you want each brake doing the exact amount of work necessary for the weight load it's managing now what rest the Neff ones car weight is distributed roughly 45 55 ie 55 percent of the weight is supported by the rear tires but under heavy braking the weight shifts forward to as much as fifty five forty five so you'll tend to end up setting a brake bias to about 55% from woods too much front brake bias and the Front's will grip too tightly and lock the wheels causing heavy understeer too much rear brace and the back wheels can lock and cause the car to become unstable and maybe spin ideally you want all your brakes to deliver their maximum force and if you push slightly too hard all the wheels should lock in unison but hurrying on the side of front bias is wise as I lock up the front at least keeps the car stable not throwing it into a spin drivers can adjust brake bias between corners from within their cockpit but this is only allowed while the car is off the brakes f1 brakes are a complicated technology with the potential for phenomenal stopping power with such state-of-the-art materials and design half the battle continues to be managing brake temperatures and bias throughout each session to keep degradation at bay and to try and ensure the brakes are in the perfect temperature range for every braking zone [Music] [Music]

Channel: Chain Bear F1

Views: 933,359

Rating: 4.9352818 out of 5

Keywords: f1, formula 1, explained, how to, racing, how does, cars, brakes, carbon brakes, baking system, mguk, mgu-k, hybrid brakes, deceleration, brake failure, brake fail, brake dust, brake duct, duct, ducts

Id: 0ykCdaRzn5g

Length: 10min 50sec (650 seconds)

Published: Tue Jun 12 2018

Reddit Comments

[u/AER0__]

This guy always explains whatever topic he's covering super well. I love learning more about F1 cars, and he is a great source to learn from.

[u/[deleted]]

Obliviously called BBW. Fantastic. More things should be named like this. We could have a Mechanical Internal Limiting Feature.

[u/MrHyperion_]

I didn't know front brakes weren't BbW

[u/dblayne]

I attended my first F1 race in Melbourne in 2018. I sat opposite turns 1 and 2. I loved the sounds of the cars as they accelerated, but the braking into turn 1 is what got my attention every time. I could feel and hear the energy transfer under hard braking.

Great video. Chain Bear produces easy to understand content.

[u/FilipJQ77]

Chain BAEr F1

[u/yatlvcar]

Awesome video. Very nice and well explained.

[u/drDEATHtrix9876]

Woah I just thoroughly enjoyed watching this at 2am . What a fantastic video I'll be looking for more! Ted Kravitz better watch out! CHAIN BEAR F1 got skills!

[u/pawaalo]

He's the reason why I started liking F1. Makes the learning curve so much smoother!

Thanks chamber!

Edit: chamber.

[u/Jtg_Jew]

I love this guys content, always a great watch.