rithsleeper

Can someone explain why bigger brakes improve stopping distances? I know obviously the more surface area the mor friction can be created, but here is where it gets foggy...

If I had absolutely perfect pedal control I could keep my brakes at the point just before lockup. If my brakes are capable of locking the tires then why would bigger brakes be any better.

I know they dissapate heat easier and that's why I upgraded because of brake fade on the track. But regular highway driving and even just cold brakes from 150mph to 0 shouldn't need to dissapate heat that quickly to maintain the ability to lock up of max brake. Its only when the rotors get hot do you get brake fade.

Hope this is clear as mud what im asking. Basically is there any benifit on the street for big brakes and slotted and all that crap ricers do and never use...

oldalaskaman

Base brakes are excellent for street driving, you answered your own question, if you have open wheels they look really cool though

VETTEHIGH

Spent $$$$ for Baer, but I did not need them at all. They just look a million times better

65Z01

I suspect that those brakes get red hot if stopping rapidly as possible from 150mph to 0mph...

drmrman

Other then All the obvious points you made..... I feel like I have much better control over the brake pedal with the larger calipers. Plus they are slightly more sensitive allowing less pedal pressure and more comfort. Instead of mashing the pedal. Alittle more finess and a lot less mashing.... That's just my opinion.

bb62

To try to answer your questions:
1. It is not just about heat dissipation. Brakes act as a heat sink. The more energy they can absorb, the farther you will be from brake fade. Obviously, the ability to cool the brakes allows the brakes to continue as a heat sink.

2. Bigger brakes don't improve braking distances, better tires do. But since faster stopping means more heat transfer, bigger brakes assist with the dissipation of the heat (or energy captured) more efficiently.

3. Anytime you achieve lockup of your tires, your braking capability is significantly reduced. And it has nothing to do with the brakes. It's all about the tires. A tire at the limit of adhesion has better grip than a sliding tire beyond the limit of adhesion. Let's put it another way, since tire capability is what causes acceleration in any direction (forward acceleration, braking, lateral acceleration or cornering), which is better for a drag racer, a spinning tire or one that hooks right away? Braking is no different.

4. On your final question - yes, big brakes are of little usefulness for street driving. In fact, they are a detriment. Why? Because if street diving is all you will ever do, then the extra mass will harm (however incrementally) the ability for the car to perform (with acceleration, cornering, fuel economy...)

desertmike1

Well said...

larger diameter rotors will offer better clamping "leverage" this is why it takes less peddle effort to stop at the same distance, larger diameter rotor's offer a larger "swept" area for heat Dissipation...overall a much better set-up

PLRX

I have C5 HPS brakes on both Vettes and likely I will be upgrading the brakes on the 96 sooooon.

rithsleeper

Well that confims my original thoughts. I don't understand why a pagaini zonda will stop shorter from say 150 than our corvette with the same tires. I guess it is totally about weight difference and driver pedal control.

jmgtp

Just a shot in the dark and by no means backed up by fact or science, but....consider, if you lock the wheels up, the brakes themselves are no longer dissapating heat to make you stop - at that point its just the friction between the tires and the road.

If you don't lock them, then the brakes are working to convert your foward momentum into heat. Bigger the brakes, the better they can convert your foward momentum to heat, shorter the stopping distance. I'm sure they also have a lot more clamping force, etc.

PLRX

Our cars are old, for its day we ruled the streets....not anymore.

Todays 4 bangers have 13 inch rotors, weight less and most of them have 17"- 18" wheels.

Alan777

Better/bigger tires, stronger grabbing calipers, less weight(i think), much better chassis, better brake materials.

BBK's don't decrease stopping distance, they help brake fade. You've also got more rotating mass when you bigger.

drmrman

OOOOOH YEAH!?!?!?!?!?!?!?!?!?

tehcarguy

The zonda has a radically different suspension setup than our corvettes, and is able to keep that same tire planted better because of it.

PLRX

yep

blackozvet

Everyone has made some good points, bigger discs will soak up and dissapate more heat, more (or larger) pistons in a caliper will generate more clamping effect, good tyres will work better but dont forget the weak link in the braking system, the brake fluid,
heavy braking can generate 500, 600, 700 degrees or more but most people run dot 4 fluid that boils at around 400 to 500 degrees and wonder why their brakes fade, dot 4 is generally ok for street use and some spirited driving but not for track days etc,
To maximise the braking system you need to upgrade to dot 5.1 synthetic which has (dependant on the brand) a boiling temp above 600 degrees. Castrol SRF for example has a very high boiling point but is expensive !
and dont confuse dot 5 silicone with dot 5.1 synthetic fluid, they are different beasts, dot 5 silicone cannot be used in ABS systems.

rithsleeper

Makes sense, I run dot 4 right now and would hate to get fade from my fluid after this upgrade. To me it seems there are a lot of passageways in the braking system, how would I go about changing the fluid completely? Can I just put likke food coloring in the resevior and then bleed till it comes clean?

Nathan Plemons

If your brakes have the ability to lock up the tires then nothing you can do to improve the braking "force" will help decrease distance, you've already stopped your tires dead, there is nothing more you can do.

As others have mentioned it's all about repeatability. Speaking from the experience of having boiled my brake fluid before on the track, you want the ability to absorb and dissipate as much heat as possible. I don't need brakes that work 9 out of 10 times....

PLRX

rithsleeper

This was my inital hunch but I wanted to make sure I wasn't missing something. I can make the move to dot 5.1 pretty easily. But how can I make sure im not mixing it and completely get new fluid in my lines? Or will it even matter if there is a little mix?