brake system

[akbavy]

what do i look for while buying new master cylinders and brake callipers .
what makes ap racing and brembo so much better than the rest ?

[M. Nader]

what makes ap racing and brembo so much better than the rest ?

What you actually need

[MCoach]

What you actually need

Think about what makes a brake system work. Now think about what makes a GREAT brake system work GREAT. Is there certain parameters that need to be tightly controlled?

What happens when a designer uses equally lightweight parts, but not of the appropriate material or design?


This isn't a rhetorical question, I'm looking for you to ask yourself and come back with an answer (even if you think it may be wrong). The people here can help you find the answer.

[akbavy]

What i want to know are the parameters , what all parameters for each brake system component makes them work really well. for example :
brake pads - how much friction they provide to the discs . the temperatures they are effective at .
good discs - being lightweight and have high torsional stiffness .
well , i want to know what makes them work really well . what kind of quality in a calliper one should look for - the pressure it is able to apply
master cylinders ...
questions for example : what is the difference between an AP racing master cylinder and a cheap master cylinder ?

[MCoach]

What i want to know are the parameters , what all parameters for each brake system component makes them work really well. for example :
brake pads - how much friction they provide to the discs . the temperatures they are effective at .
good discs - being lightweight and have high torsional stiffness .
well , i want to know what makes them work really well . what kind of quality in a calliper one should look for - the pressure it is able to apply
master cylinders ...
questions for example : what is the difference between an AP racing master cylinder and a cheap master cylinder ?

That's what we're looking to answer here.

You've identified several factors already, but I want to ask you these questions!

How much friction does it take to stop a car? .3 mu? .6 mu? 1 mu?
-by surveying a lot of data from manufacturer's (Wilwood hands their pad data out like candy) you can find what's normal. Estimate the tire mu, that'll be needed.

How hot must the brakes be to work efficiently? 300C? 20C? 600C?
Consider the working properties of the metal and pads. Look up the pad temp vs mu curves to get an idea.
Test to find out if you run into strange issues like locking fronts first at low brake temps, and rears first at high brake temps (I've seen it happen, need to account for it).
Test to find out the lifetime of the components. Will the pads wear out after a certain amount of use? We currently run a pad compound that others have run into problems with wearing out way too quickly, while we on the other hand have used 1 set for all of our competitions and testing.

How lightweight must the discs be?
Well, it depends what problem you think you might run into first. Dumping enough energy into them to cause a "reactor meltdown" and fail them or something more like fatigue cracks that lead to their eventual demise. Can you even package a rotor as light as you want it? Don't worry about the stiffness of the rotor, whatever design you come up with will most likely be very strong, unless you start putting crazy slots in it that are just asking for trouble.

Master Cylinders. What bore size and why? Is there a reason some people use .5" (12.7mm) bore pistons and others use a 1" (25.4mm) bore piston? If you choose a really small bore size, the housing will most likely be smaller, but is there anything else that could be bad about that? Think about the function of the component and forces it generates.

Calipers are on the opposing side of this, but have the same concern. Oh boy, a hint!
Why use tiny calipers? Why use giant calipers? What affect does line pressure have on anything?
Here is a big lead, hysteresis. In a braking system, what could cause this problem? Something has to change.


What could change so much in calipers and master cylinders? Identify this one thing we can move forward.

[acedeuce802]

Also, in your quest to learning brake design, go ahead and make a design spreadsheet. You will learn that it's possible to get the same braking force with different size master cylinders and caliper piston bores. When you run the calculations (use google, and/or Stoptech design articles), you will start to understand the affect that these parameters have on other things, such as line pressure and pedal travel. Think about whether you want more or less line pressure and pedal travel, and choose your master/calipers accordingly. Calculate heat transfer (kinetic/thermal energy?).