Yeah forgive me for trying to use fundamental laws of braking rather than qualitative "evidence" to back up my point . I guess all the physicists should just give up now since apparently laws are no match for questionable personal experience.

 

Very true................
Then again, I remember reading a thread where you apparently knew more than a mechanical engineer too..................

As I said, until you can provide evidence to the contrary on a Ralliart, then you have as much credability as Billyboys results without measurements. You say one thing, he says another. At the end of the day, only one of the 2 people have actually tested it on their car.

 

Yes because everyone is whatever they say they are on the internet . Did you know I'm a billionaire genius race car driver? I said I am therefore I am. Moreover, we were actually arguing the same thing just using different lingo.
That is the logical thing to do, when someone cannot directly disprove an idea, it is only natural to fully believe in that idea despite evidence to the contrary and no actual evidence supporting it. Ignore the fact that this idea flies in the face of fundamental and well established physics that is used in the world of racing and by manufacturers when they actually design cars. Did you know that elves actually exist? Nobody has been able to disprove their existence, therefore, by your logic, they exist.

 

Forgive me oh great one........................ I didn't realize you were Michael Schumacher

It seems that if somebody doesn't agree with you, you come back with a whole heap or reference material to attempt to support your claims, but none of it is relevent to the actual vehicle you're talking about.

The way the physics work car - car is different. Fundamentally they use the same equations, but the way they operate differs. Hence I keep asking for relevent testing from the car we're actually talking about.

Oh yeah, Santa's real but he's not delivering you any pressies this year cause you ran him over when you failed to stop 3 feet sooner

 

OK, this is getting stupid. Physics does not chage car to car, it's ****ing physics. Tires work the same whether it's on a truck, WRX, Ralliart, Ferrari, whatever. Brakes work the same as well. Jesus tap dancing christ.

 

Are you serious??????????

The way the physics work car - car is different. As I said, the fundamentals stay the same, but the way the cars operate with them changes.

 

Everybody needs to calm down a bit, please.

 

I literally killed myself on the last page. It has been demonstrated over and over again what the purpose of a BBK is. The thermal differences speak for themselves. The stopping distances don't. I don't even understand what in hell is really being argued at this point.

 

I don't either, apparently the Ralliart defines the laws of physics or something.

 

I wonder what kind of affect that has on the resale value...

 

It's really simple to understand. Look at any high end brake setup (F1 car, exotic car, high end brake kits, etc) Everything in them is designed around 1 goal - disperse as much heat as possible as fast as possible. Carbon ceramic rotors = better heat tolerance. Larger pads = spread out the heat from braking so as not to melt the pad. Vanes in rotors = get rid of more heat. Brake ducting, same thing.

If the goal were to increase braking force, all they'd have to do is reduce the size of the brake pad. However, doing that and it wouldn't take much to overheat and melt the pad. Look at clutches, they follow this exact idea. Need a clutch disc that can grab harder and hold more power? Go with a pucked clutch that has a reduced surface area and can transfer more force from the pressure plate into the flywheel. Downside is pucked clutches have a shorter lifespan because they run hotter. Brakes are the same way.

Braking is all about heat. Now, looking at a street car, if you're having problems with boiling brake fluid, overheating pads and rotors, etc, then you need to look at heat reducing options, such as ducting and BBKs. Otherwise, simply pad, line, and tire upgrades are what you need to reduce stopping distance.

 

What I get from this debate is braking improvement see's little return from improved frictive coefficients of brake mating surfaces, and nothing to do with increased clamping force.

Shortened braking distances result from the combination of stickier tires with the improved heat dissipation of a larger rotor/caliper combination.

Even under a one-time emergency stop, the larger brake combination evacuates heat from the mating surface more efficiently. This larger displacement of heat at the mating surfaces provides an increased time frame for brake pads to operate optimally, all other given forces being equal. If all things are equal (friction materials, temp, tires), the lengthening of time at which friction surfaces operate best, is the only thing elevating increased braking function. This improved function would not be constant, but would increase toward the end of a braking procedure.

Lengthened optimal functioning (time) can then be utilized by the tire/roadway combination, if capable. For unmodified brakes: Brake fade toward the latter part of the operation will be evidenced by reduced brake pad function corresponding to the higher temperature. The larger brakes merely keep the tire/roadway braking in an OEM-state for a longer period of time. This results in a continuance of optimal braking during the end of the operation, and the "reason" you see the minor improvement in braking distances vs. stock brake combinations.

To further this thinking, the caliper/rotor systems of our brakes has far-far more clamping force than what would be needed to one-time stop the car from 60mph-0mph in 50ft, yes 50ft. However, there simply is not a tire advanced enough to do the same, nor would you want (or your other automotive components) to experience such decceleration.

 

Stopping distance usually is not related to heat dissipation. Tires are the number one factor, simply put, stickier tires allow the brakes to exert more force on them without locking them up. A higher coefficient of friction does lower stopping distance by increasing braking force but again, you have to be able to use that increased force with stickier tires. Larger rotors help with heat dissipation but this isn't an issue for a one time emergency stop. If you're racing, this can mean the difference between happy brakes and overcooked brakes that don't stop you at all. I don't know of any brake pads, OEM or not that suffer from brake fade after one hard stop.

 

I understand the tire/road part of this. Here lies my confusion:
Let's say there is a tire which will stop a car in 100ft. using OEM brakes before abs activates. Everything else being the same and utilizing equal frictive force, a larger brake combination is substituted. The substituted brake system stops the car in 98ft before abs activates.

If not temperature-related, what is the cause?

Low brake temperature won't result in optimized frictive force/time to the tires?

High brake temperature decreases frictive force/time to the tires.

 

Well generally speaking, when people install a BBK, they're changing the brake pads as well which is the likely culprit. The OEM pads will be designed to operate properly during a hard stop, they won't be moving outside of their operating temperature. To get brakes truly hot enough to fade, you have to driving very hard.