Why are expensive brakes better?

[Matt Andrews]

couple reasons I will be putting the Essex sprint brakes on my track car:

1. pedal feel - I'm not convinced my dissatisfaction with the stock system wasn't tread squirm of the RS3's.
2. heat capacity
3. unsprung weight - 2 piece rotors save a ton of weight. 8lbs/corner on the essex sprint kit
4. rotor life - stock rotors with upgraded pads worked ok on the track, but the rotors got really cooked. I am curious how long they will last before they crack.

[Racecomp Engineering]

The Essex AP Racing brakes seem like an excellent kit at a reasonable price.

And here's a note on what happens when you get a "cheap" big brake kit:

Originally Posted by andreitentean

Same tests for both sides, left and right.
You can see in the movies that the calipers are expanding under pedal pressure, this is bad manly for the performance orientated customer how will want some feedback from the brake pedal ! Pressure is wasted in the bad design and probably bad material caliper instead of going to the pistons and so on to the pads !

LEFT D2 caliper expanding under pressure

RIGHT D2 caliper expanding under pressure

Here you can see that using a dynamometric wrench we could approximate the effort needed to turn ONLY the disc – 30 Nm to a side and 45 Nm to the other !!! This is EXTREME ! This D2 people are wasting our hard earned horsepower !!
LEFT D2 rotor 45Nm to rotate

RIGHT D2 rotor 30Nm to rotate

And here you can see and imagine the shacking under braking !! discs are ****ed up in less than 2000km, that is less than 1250 miles !!
LEFT D2 rotor moving left and right

RIGHT D2 rotor moving left and right

LEFT D2 rotor moving up and down

RIGHT D2 rotor moving up and down

So maybe I am unfortunate, or maybe I really do not know how to brake or use a set of brakes, or even both, but I will not come close to the D2 ever again. Anybody can make mistakes but not to take responsibility for your product is not Ok. Hope this helps.

http://forums.evolutionm.net/evo-tir...-shacking.html

- Andrew

[7thgear]

Originally Posted by Matt Andrews

couple reasons I will be putting the Essex sprint brakes on my track car:

1. pedal feel - I'm not convinced my dissatisfaction with the stock system wasn't tread squirm of the RS3's.
2. heat capacity
3. unsprung weight - 2 piece rotors save a ton of weight. 8lbs/corner on the essex sprint kit
4. rotor life - stock rotors with upgraded pads worked ok on the track, but the rotors got really cooked. I am curious how long they will last before they crack.

so it's up to 8lb per corner now? i thought it was only 4

which is a lot regardless considering how brakes are in general.

[ultra]

A simple test - find somewhere nice and quiet and try braking as hard as you can from 80mph to 20 mph repeatedly.

Chances are that you'll do excellently the first few times but notice that heat? Funky smells? Smoke? More heat? Glowing rotors? No more brakes?

I like to think of brakes as machines for converting kinetic energy into heat. Of course brakes aren't 'perfectly efficient' systems so after a certain equilibrium is reached their performance degrades as temperatures rise beyond their operating (thermal efficiency) evelope and various parts in the system begin to fail.

Why good (not necessarily big) brake kits cost what they do is because the good ones are are designed to perform consistently for much longer in an entirely different operating envelope than 'normal' brakes are required to. To do so they require more effort in terms of engineering, development, higher quality materials and tighter tolerances.

You can get pretty far by upgrading parts of the stock braking system but depending on your application you may well reach a point where you've already upgraded much of the system but it (the system) can't hold up well enough, i.e. too much performance degradation or component failure.

Matt Andrew's case os a prime example - a high level of driving skill and a requirement to run a large number of fast laps. He's already done pads, fluid and (I'm assuming) brake lines which has exposed the rotors as the next point of failure. The only thing after that is two piece rotors perhaps, but by this point the value/money equation logically begins to tilts towards an entirely different, higher end system since the stock calipers will be the next weak link in the chain.



TL;DR most people probably don't need 'em but it depends on the need.

[fatoni]

Originally Posted by FrX

The formula for friction is: Ff = u * Fn

Ff = Friction force
u = Coefficient of friction
Fn = Normal force

There is no term for area. When the surface area is larger, the normal force is spread out over said larger area. Thus, each unit of area receives less force applied and the total force remains the same.

i know the formula. notice how there is also no term for heat. do brakes never fade? im not saying that are absolutely does change things. im just saying that its very well possible

[hotaka]

Originally Posted by ultra

A simple test - find somewhere nice and quiet and try braking as hard as you can from 80mph to 20 mph repeatedly.

Chances are that you'll do excellently the first few times but notice that heat? Funky smells? Smoke? More heat? Glowing rotors? No more brakes?

Your test might be easier just to pull the hand brake half way, and step on the gas half way and keep it there. The car should start to accelerate as the brakes start to overheat, although I've never done it before

[Matt Andrews]

Originally Posted by 7thgear

so it's up to 8lb per corner now? i thought it was only 4

which is a lot regardless considering how brakes are in general.

I was told it was 8lbs a corner. If I'm wrong, Id like to know before they show up. I think the endurance package was only a couple lbs a corner?

[wheelhaus]

Originally Posted by BlaineWasHere

So, if you have more tire grip than brake power larger brakes don't equal more stopping power to take advantage of tire grip? I understand the larger surface areas do better with the heat. I'm just trying to understand, and as you can see I'm struggling.

You're correct, stickier tires can utilize more braking torque, but only if the braking system is capable of providing it. More braking power can be applied in any combination of the following three ways: more pressure, higher friction pads, or more leverage (larger rotors).

You're still slowing down the car's mass (converting kinetic energy into heat), the difference is how the brakes cope with it. Sticky tires can slow the car faster, which generates more heat, more quickly.

The point is (for the FRS/BRZ), the stock brakes are pretty damn good, mostly due to the car's light weight. For street use (even moderately aggressive driving), the stock pads are fine. For aggressive street use (like canyon carving) or track days, upgrade the pads to something rated for street & track use (not race pads, they require a lot of heat to work properly, and don't work so well on the street with lower operating temps). You don't need a BBK unless you're racing with really sticky tires or REALLY whoring at the local track. Constant hard laps (over time) can overwhelm almost any stock system.

[jadewbj]

http://www.zeckhausen.com/Testing_Brakes.htm
Ok a BBK can (if done right) increase stopping power? Same car same tires better stops with a BBK.

[czar07]

I think you will find that 90% of people get BBKs for looks.

[7thgear]

Originally Posted by jadewbj

http://www.zeckhausen.com/Testing_Brakes.htm
Ok a BBK can (if done right) increase stopping power? Same car same tires better stops with a BBK.

same pads?

[Racecomp Engineering]

Stopping power and stopping distances are not the same. In that test they got shorter stopping distances by modifying the brake bias.

- Andrew

[Dave-ROR]

Originally Posted by Xanatos

It depends on how you would like to drive your car. If your doing daily driving on normal roads a new brake kit won't be too much better. If you are on the track you ride the brakes alot and the brake rotor heats up and essentially fails to perform so you will see loss in braking power. The better brakes will have larger surface area so that temperatures don't get as hot and better materials that withstand more heat before breaking down.

You can always adjust the braking power if the kit ends up locking up too much.

Learning to drive and learning how to use the brakes correctly is a lot cheaper than a BBK.

[Dave-ROR]

Originally Posted by ABQautoxer

Because the heat generated from a 5000lbs+ SUV vs a 2700lbs sports car are not the same. There is a minimum amount of braking needed for each type, anything beyond that is overkill. The point being for the 86s, the stock brakes with upgraded pads will be more than good enough at its stock weight/power. Now up the power and/or weight and you have to recalculate that formula. Make sense?

It's also harder to stop a Donk's 36" wheels than an SUVs normal 17" wheels.