Brake Pad Dust Issue

[smooth1]

I admit your points would be compelling if we were arguing over you eating your broccoli or brushing your teeth before nap time.

Here? Not so much.

I don't mind being wrong anywhere near as much as I mind your " Ultimate Ego I'm right" attitude! I think everyone can see that broccoli you have stuck between your teeth from the big grin on your face. I keep reminding myself your not tech, you just found an article or info that soemone else has put together and studied.

So, about your Pulp Fiction article, it was written in 1991. Alot has changed since then. In 1995, those same scientists argued that the maximum amount of g force that could be applied to a tire is 1G. Yet, we have all seen and sometimes been the person who has exceeded that limit. Are you familiar with the formula to acheive a hp rating for your brake system? Do you know how many ft. lbs. of energy are lost during that braking? Do you know the formula for calculating braking power? Do you know that since that article was published, Brake assist, Electronic Brakeforce distribution systems, and stability control systems have been invented, advanced and refined? Which by the way, have been able to produce even shorter and even more controllable stopping distances? And all those systems incorperate the formulas listed above. The ABS system your comparing to is actually called a Reactionary prevention system. the new systems that have since replaced that out of date ABS system now use those formulas to calculate input from alot more sensors than just the tires as before. Of course in those systems the pads don't matter, because they didn't have a sensor on the pad, they had a sensor on the tires only. So that's why the tires were the important factor. So you can keep carrying your big club around whacking people on the knees with it all you want to. Todays braking systems utilize every aspect of braking from the driver input to the road and the surface your driving on. The entire braking system is only as good as the weakest component. Sometimes that's not the tires. I don't drive from 0-60 and then just slam on the brakes and get out. I drive my car in the real world. And in the real world, pads matter, rotors matter, tires matter, everything matters.

[Knightshade]

Yes, but the pads -still- don't change stopping distance.

I notice you go after the source written in 1991, but not the numerous others, like Brembo and Stoptech who say the same thing -today-.... that pads CAN NOT change stopping distance.

and of course I know the formula for the force involved in braking... that lovely 1991 article explains it in great detail in fact.

The only place in the equation that the pads enter at all is when you mutliply the force from the caliper by the pads coefficient of friction.

As long as the pads can engage the ABS system you will come up with a number greater than the amount of force the vehicle can make use of due to the limitations of the tires. (that would in fact be WHY the ABS system ends up engaging). Thus a higher amount of force from a higher CoE would be completely wasted extra force. It certainly wouldn't make the car stop faster. It couldn't.

As to my "ego"... hardly. I was very polite the first several times I explained Barkats error to him. It was only when he (and you) kept jumping up and down insisting you must be right despite all evidence to the contrary and that clearly I had no idea what I was talking about despite every expert on the topic agreeing with me that I began taking on a less polite tone. Even when Barkat devolved to "Nu uh!" replies I continued to provide reliable sources and articles all supporting the point I was making while he provided nothing but "Nopenopenope!"

I don't think it's my ego that was having a problem here.

And I'm not sure why you feel I'm "not tech" when I appear to be the only one in the debate who actually understood the articles that were being posted and had the correct answer from the beginning.

If you or barkat were "tech" you would've admitted the point after the first source or two that explained the technical reasoning for pads not changing stopping distance.... or after the third or forth, or after.... well, you ge the point.

[Gaugster]

i got all this from my thread and all i asked was about the brake dust issue....now i got a full on report on breaking and pads and traction and friction...

damn i love this site.

Yeah, troll alert........

We're splitting hairs here and it seemed to have turned into a personal thing. It's all about static vs. dynamic friction IMO. Methods for applying the brakes are different from ABS vs. non-ABS vehicles.

It is a matter of deciding which of the many factors (tires, road, brakes, brake lines, fluid, Pre-Collision System, vehicle weight etc...) has the most dominate affect on the stopping distance of the vehicle.

In less then ideal conditions like rain and snow, it’s all about the tires 100% as locking up the wheels is easy.

In very ideal condition, tires are still a very major factor but some of the other aspects can come into play IMO.

Knightshade is considering a very special application of the brakes where only the ISx50 is considered and maximum force is applied and the wheels will lock up instantly. Others have declared this to be a falsehood and then went on to discuss the “other aspects” I mentioned above.

I think Knightshade is correct given that his example is very specific and limited. The other comments are true for a host and “what if” scenarios – most of which can be relevant for daily drivers.

Regards,

[Knightshade]

I admit your points would be compelling if we were arguing over you eating your broccoli or brushing your teeth before nap time.

Here? Not so much.

Todays braking systems utilize every aspect of braking from the driver input to the road and the surface your driving on. The entire braking system is only as good as the weakest component. Sometimes that's not the tires. I don't drive from 0-60 and then just slam on the brakes and get out. I drive my car in the real world. And in the real world, pads matter, rotors matter, tires matter, everything matters.

That's great.

None of it was the actual topic though.

We went through this the last time you tried to make a post that sounded informed and had nothing to do with the discussion.

The discussion was stopping distance. Which is generally measure as a slam-the-brake-pedal stop. Most commonly from 60-0. By pretty much everybody who tests stopping distance.

You keep wanting to bring in racing (last time) or "real world" (this time- which you don't actually define) and then insist it has bearing on what we're discussing.

I've said since the begining I am NOT talking about racing or other abuse of brakes...but also mentioned repeatedly how pads -can- matter there, and in what ways.

Are you just grasping for something even marginally related you can try to be right about now? Because it's a topic I already covered pages ago in the thread.

And even then, better pads CAN NOT improve stopping distance.

They CAN increase the number of stops you get before stopping distance gets _worse_ due to fade though.. which isn't at all the same thing. They still don't shorten the distance of an initial stop. They can't.

Again, I suggest you read the conclusions of the PF article... it explains the 4 things that brake system modifications can accomplish, most of them having to do with changing the feel of the system or increasing its ability to handle thermal extremes you might encounter on a track. I went over them more simply earlier in the thread.

none of the things that those mods changed was stopping distance though.

Even the folks trying to -sell- you brake upgrades (the honest ones anyway, like stoptech and brembo) admit that.

[Knightshade]

i got all this from my thread and all i asked was about the brake dust issue....now i got a full on report on breaking and pads and traction and friction...

damn i love this site.

Yeah, troll alert........

We're splitting hairs here and it seemed to have turned into a personal thing. It's all about static vs. dynamic friction IMO. Methods for applying the brakes are different from ABS vs. non-ABS vehicles.

It is a matter of deciding which of the many factors (tires, road, brakes, brake lines, fluid, Pre-Collision System, vehicle weight etc...) has the most dominate affect on the stopping distance of the vehicle.

In less then ideal conditions like rain and snow, it’s all about the tires 100% as locking up the wheels is easy.

In very ideal condition, tires are still a very major factor but some of the other aspects can come into play IMO.

Knightshade is considering a very special application of the brakes where only the ISx50 is considered and maximum force is applied and the wheels will lock up instantly. Others have declared this to be a falsehood and then went on to discuss the “other aspects” I mentioned above.

I think Knightshade is correct given that his example is very specific and limited. The other comments are true for a host and “what if” scenarios – most of which can be relevant for daily drivers.

Regards,

Can you cite any specific conditions that occur in the real world, outside a racetrack or a chase scene from a Bond movie, where different brake pads (both in good condition and capable of engaging the ABS system) will improve stopping distance?

The only one I can think of where pads would matter at all is driving down a steep mountain... which would be another case like I discussed where some pads might take longer to fade, this preserving the same stopping distance over a longer period of time, not actually improving it per se.

But of course using lower gears would mitigate that significantly, and would be the proper way to drive in that situation.... the 2IS makes this fairly easy even with the auto.

[Knightshade]

But the brake pad isn't what stops the car.

So I guess it's more akin to you asking which brand of sticker adds more horsepower.

I will note that for -track- use the pad material can have greater relevance as after hot lapping a few times the coeficient of friction can change significantly.... but for street use? pads is pads. If it can kick ABS on it'll stop exactly as well as the next pad since you're at the limits of the brake system there. And even ON the track the pads only matter for more consistent braking without fade under extreme conditions.

Just changing pads can't stop you in a shorter distance, because the pads don't stop the car.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up.

I brought this back BTW so folks can see how the debate began, and what it was about.

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

That's absolutely 100% false, as I've shown repeatedly since, and as agreed on by the half dozen or so sources I've provided (including the guy who actually tested it on a 2IS with both sets of pads).

Bringing up a slew of other scenarios (including the couple related to repeated high speed braking I've already mentioned) isn't really relevant to the original question. I'm happy to talk about other situations, but there's a reason I was discussing one specific scenario (the typical panic stop that most folks use as their "stopping distance" test on cars.)...a situation where pads (if they can engage ABS) make no difference whatsoever.

[smooth1]

I admit your points would be compelling if we were arguing over you eating your broccoli or brushing your teeth before nap time.

Here? Not so much.

Todays braking systems utilize every aspect of braking from the driver input to the road and the surface your driving on. The entire braking system is only as good as the weakest component. Sometimes that's not the tires. I don't drive from 0-60 and then just slam on the brakes and get out. I drive my car in the real world. And in the real world, pads matter, rotors matter, tires matter, everything matters.

That's great.

None of it was the actual topic though.

We went through this the last time you tried to make a post that sounded informed and had nothing to do with the discussion.

The discussion was stopping distance. Which is generally measure as a slam-the-brake-pedal stop. Most commonly from 60-0. By pretty much everybody who tests stopping distance.

You keep wanting to bring in racing (last time) or "real world" (this time- which you don't actually define) and then insist it has bearing on what we're discussing.

I've said since the begining I am NOT talking about racing or other abuse of brakes...but also mentioned repeatedly how pads -can- matter there, and in what ways.

Are you just grasping for something even marginally related you can try to be right about now? Because it's a topic I already covered pages ago in the thread.

And even then, better pads CAN NOT improve stopping distance.

They CAN increase the number of stops you get before stopping distance gets _worse_ due to fade though.. which isn't at all the same thing. They still don't shorten the distance of an initial stop. They can't.

Again, I suggest you read the conclusions of the PF article... it explains the 4 things that brake system modifications can accomplish, most of them having to do with changing the feel of the system or increasing its ability to handle thermal extremes you might encounter on a track. I went over them more simply earlier in the thread.

none of the things that those mods changed was stopping distance though.

Even the folks trying to -sell- you brake upgrades (the honest ones anyway, like stoptech and brembo) admit that.

The discussion was stopping distance. Which is generally measure as a slam-the-brake-pedal stop. Most commonly from 60-0. By pretty much everybody who tests stopping distance.

I don't know, I tend to think that when I apply the brakes from say 45 mph, and the car comes to a stop, that is a stopping distance. Just because I haven't engaged an ABS system, doesn't mean I have or haven't acheived a point at which the brakes are applied and the car comes to stop. If I apply more pressure on the rotors, the car will have a shorter stopping distance. If I apply less, then it will take longer to stop, coorect? So if I change the brake pad, and I find myself having to apply more lever force to achieve the same stopping distance from 45 mph, then the pad did make a difference in my stopping distance correct? Even though I have compensated for that by pressing harder on the brakes? Or no, it's all the same?

[Gaugster]

Can you cite any specific conditions that occur in the real world, outside a racetrack or a chase scene from a Bond movie, where different brake pads (both in good condition and capable of engaging the ABS system) will improve stopping distance?

The only one I can think of where pads would matter at all is driving down a steep mountain... which would be another case like I discussed where some pads might take longer to fade, this preserving the same stopping distance over a longer period of time, not actually improving it per se.

But of course using lower gears would mitigate that significantly, and would be the proper way to drive in that situation.... the 2IS makes this fairly easy even with the auto.

You mentioned the one that I can think of which is the thermal issues with the pads, rotors and brak fluid for that matter. But those don't really pertain to the stopping distance tests that the OEM's and other groups perform.

[Knightshade]

I admit your points would be compelling if we were arguing over you eating your broccoli or brushing your teeth before nap time.

Here? Not so much.

Todays braking systems utilize every aspect of braking from the driver input to the road and the surface your driving on. The entire braking system is only as good as the weakest component. Sometimes that's not the tires. I don't drive from 0-60 and then just slam on the brakes and get out. I drive my car in the real world. And in the real world, pads matter, rotors matter, tires matter, everything matters.

That's great.

None of it was the actual topic though.

We went through this the last time you tried to make a post that sounded informed and had nothing to do with the discussion.

The discussion was stopping distance. Which is generally measure as a slam-the-brake-pedal stop. Most commonly from 60-0. By pretty much everybody who tests stopping distance.

You keep wanting to bring in racing (last time) or "real world" (this time- which you don't actually define) and then insist it has bearing on what we're discussing.

I've said since the begining I am NOT talking about racing or other abuse of brakes...but also mentioned repeatedly how pads -can- matter there, and in what ways.

Are you just grasping for something even marginally related you can try to be right about now? Because it's a topic I already covered pages ago in the thread.

And even then, better pads CAN NOT improve stopping distance.

They CAN increase the number of stops you get before stopping distance gets _worse_ due to fade though.. which isn't at all the same thing. They still don't shorten the distance of an initial stop. They can't.

Again, I suggest you read the conclusions of the PF article... it explains the 4 things that brake system modifications can accomplish, most of them having to do with changing the feel of the system or increasing its ability to handle thermal extremes you might encounter on a track. I went over them more simply earlier in the thread.

none of the things that those mods changed was stopping distance though.

Even the folks trying to -sell- you brake upgrades (the honest ones anyway, like stoptech and brembo) admit that.

The discussion was stopping distance. Which is generally measure as a slam-the-brake-pedal stop. Most commonly from 60-0. By pretty much everybody who tests stopping distance.

I don't know, I tend to think that when I apply the brakes from say 45 mph, and the car comes to a stop, that is a stopping distance. Just because I haven't engaged an ABS system, doesn't mean I have or haven't acheived a point at which the brakes are applied and the car comes to stop. If I apply more pressure on the rotors, the car will have a shorter stopping distance. If I apply less, then it will take longer to stop, coorect? So if I change the brake pad, and I find myself having to apply more lever force to achieve the same stopping distance from 45 mph, then the pad did make a difference in my stopping distance correct? Even though I have compensated for that by pressing harder on the brakes? Or no, it's all the same?

In order to reliably test stopping distance when changing a part you have to repeat identical conditions.

Now, if you get a robot to engage the pedal at the same pressure every time at the same speed, you'd have something.

A human with his foot though? Not as much. Hence why stopping distance is generally the slam-the-brake test, usually done from 60. It's repeatable.

(and was the exact type of stop the thread was about, hence why I requoted barkats original misinformed post about how pads matter in that type of stop when they do not)

In the specific example you cite though, no, the pad didn't change your stopping distance, it changed the amount of force you had to apply to the pedal. The car was still capable of stopping in the same distance in both examples you gave.

Now, here's the thing... if you had slammed on the brake at 45 you would have stopped in a shorter distance (regardless of pad) right?

So changing the pad made no difference to the best potential stopping distance you could get at 45 mph.

You now seem to be trying to bring up stopping when using less than the maximum input force.

Which seems kinda weird when talking about stopping distance.

You're essentially asking "How long does it take me to stop when I'm not trying my hardest to stop?"

Which is pretty hard to quantify.

But certainly if you're applying well UNDER the amount of pressure that would engage ABS then different pads (as well as other things) could change the distance it would take the car to stop given a fixed pedal input. I'm not sure how that's really relevant unless you have a very very weak leg or something, in which case you'd want a pad that required the minimum possible input force.

For people with normal leg strength any decent pad will stop the car from 45 in whatever distance less than the "optimal slam the brakes" distance they want it to, but the amount of input force required might vary.

[bartkat]

But the brake pad isn't what stops the car.

So I guess it's more akin to you asking which brand of sticker adds more horsepower.

I will note that for -track- use the pad material can have greater relevance as after hot lapping a few times the coeficient of friction can change significantly.... but for street use? pads is pads. If it can kick ABS on it'll stop exactly as well as the next pad since you're at the limits of the brake system there. And even ON the track the pads only matter for more consistent braking without fade under extreme conditions.

Just changing pads can't stop you in a shorter distance, because the pads don't stop the car.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up.

I brought this back BTW so folks can see how the debate began, and what it was about.

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

That's absolutely 100% false, as I've shown repeatedly since, and as agreed on by the half dozen or so sources I've provided (including the guy who actually tested it on a 2IS with both sets of pads).

Bringing up a slew of other scenarios (including the couple related to repeated high speed braking I've already mentioned) isn't really relevant to the original question. I'm happy to talk about other situations, but there's a reason I was discussing one specific scenario (the typical panic stop that most folks use as their "stopping distance" test on cars.)...a situation where pads (if they can engage ABS) make no difference whatsoever.

You need to stop the misquoting and stop the little flames. I'm sure they sound good to you but they are dishonest and some are very close to rule violations.

There is no such thing as the brake pads instantly stopping the rotating wheel/tire/brake assembly. That short time it takes to stop the rotation adds to the braking distance because it takes place before the tires stop and reach their limit of adhesion. That time translates to distance. That's a fact and nothing you have said or cited disproves it.

[Knightshade]

But the brake pad isn't what stops the car.

So I guess it's more akin to you asking which brand of sticker adds more horsepower.

I will note that for -track- use the pad material can have greater relevance as after hot lapping a few times the coeficient of friction can change significantly.... but for street use? pads is pads. If it can kick ABS on it'll stop exactly as well as the next pad since you're at the limits of the brake system there. And even ON the track the pads only matter for more consistent braking without fade under extreme conditions.

Just changing pads can't stop you in a shorter distance, because the pads don't stop the car.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up.

I brought this back BTW so folks can see how the debate began, and what it was about.

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

That's absolutely 100% false, as I've shown repeatedly since, and as agreed on by the half dozen or so sources I've provided (including the guy who actually tested it on a 2IS with both sets of pads).

Bringing up a slew of other scenarios (including the couple related to repeated high speed braking I've already mentioned) isn't really relevant to the original question. I'm happy to talk about other situations, but there's a reason I was discussing one specific scenario (the typical panic stop that most folks use as their "stopping distance" test on cars.)...a situation where pads (if they can engage ABS) make no difference whatsoever.

You need to stop the misquoting and stop the little flames. I'm sure they sound good to you but they are dishonest and some are very close to rule violations.

There is no such thing as the brake pads instantly stopping the rotating wheel/tire/brake assembly. That short time it takes to stop the rotation adds to the braking distance because it takes place before the tires stop and reach their limit of adhesion. That time translates to distance. That's a fact and nothing you have said or cited disproves it.

How did I misquote you when I quoted your entire post in full? You calling me dishonest when I've been nothing BUT honest sounds a lot more like a flame than anything I said.

And everything I'd said disproved your claim. Even Smooth1 and Gaugster have agreed for the specific case you were discussing that you are wrong.

Do you even know what a brake pad does? Because it really doesn't sound like it.

"time" does not appear anywhere in the equation to compute braking force. The pads never "stop" anything at all.

All the pad does is take the clamping force from the caliper and apply it to the rotor.

To calculate the force acting on the rotor you need to know the clamp load from the caliper and the coefficient of friction of the pad. It's an instantaneous calculation.

The pad is a pad, it doesn't need "time" to generate maximum force if the caliper is already providing it.

Your continued insistence on this belies a gross lack of understanding of what the parts you're discussing are even doing.

[bartkat]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

[Knightshade]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

Yes, those were your exact words.

Which I used in a post that had YOUR ENTIRE POST quoted at the top.

Seriously dude.

[bartkat]

But the brake pad isn't what stops the car.

So I guess it's more akin to you asking which brand of sticker adds more horsepower.

I will note that for -track- use the pad material can have greater relevance as after hot lapping a few times the coeficient of friction can change significantly.... but for street use? pads is pads. If it can kick ABS on it'll stop exactly as well as the next pad since you're at the limits of the brake system there. And even ON the track the pads only matter for more consistent braking without fade under extreme conditions.

Just changing pads can't stop you in a shorter distance, because the pads don't stop the car.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up.

I brought this back BTW so folks can see how the debate began, and what it was about.

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

That's absolutely 100% false, as I've shown repeatedly since, and as agreed on by the half dozen or so sources I've provided (including the guy who actually tested it on a 2IS with both sets of pads).

Bringing up a slew of other scenarios (including the couple related to repeated high speed braking I've already mentioned) isn't really relevant to the original question. I'm happy to talk about other situations, but there's a reason I was discussing one specific scenario (the typical panic stop that most folks use as their "stopping distance" test on cars.)...a situation where pads (if they can engage ABS) make no difference whatsoever.

You need to stop the misquoting and stop the little flames. I'm sure they sound good to you but they are dishonest and some are very close to rule violations.

There is no such thing as the brake pads instantly stopping the rotating wheel/tire/brake assembly. That short time it takes to stop the rotation adds to the braking distance because it takes place before the tires stop and reach their limit of adhesion. That time translates to distance. That's a fact and nothing you have said or cited disproves it.

How did I misquote you when I quoted your entire post in full? You calling me dishonest when I've been nothing BUT honest sounds a lot more like a flame than anything I said.

And everything I'd said disproved your claim. Even Smooth1 and Gaugster have agreed for the specific case you were discussing that you are wrong.

Do you even know what a brake pad does? Because it really doesn't sound like it.

"time" does not appear anywhere in the equation to compute braking force. The pads never "stop" anything at all.

All the pad does is take the clamping force from the caliper and apply it to the rotor.

To calculate the force acting on the rotor you need to know the clamp load from the caliper and the coefficient of friction of the pad. It's an instantaneous calculation.

The pad is a pad, it doesn't need "time" to generate maximum force if the caliper is already providing it.

Your continued insistence on this belies a gross lack of understanding of what the parts you're discussing are even doing.

Get another "expert" to read your post and then get back to me on how many things they find wrong with it.

Over and out.

[bartkat]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

Yes, those were your exact words.

Which I used in a post that had YOUR ENTIRE POST quoted at the top.

Seriously dude.

Exact words where? You omitted several words from your "quote". Makes a difference.

[Knightshade]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

Yes, those were your exact words.

Which I used in a post that had YOUR ENTIRE POST quoted at the top.

Seriously dude.

Exact words where?

IN YOUR POST.

"I'm talking one panic stop from road speed." was the complete sentence. Which I used right below YOUR ENTIRE POST FOR CONTEXT.

You even quoted it back to me several times in your last few posts.

Just... wow.

[bartkat]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

Yes, those were your exact words.

Which I used in a post that had YOUR ENTIRE POST quoted at the top.

Seriously dude.

Exact words where?

IN YOUR POST.

"I'm talking one panic stop from road speed."

You even quoted it back to me several times in your last few posts.

Just... wow.

Read again. Read it all. Quote it all.

[Knightshade]

Barkat insisted that for "one panic stop from road speed" pads would be a major factor in stopping distance.

Yes, those were your exact words.

Which I used in a post that had YOUR ENTIRE POST quoted at the top.

Seriously dude.

Exact words where?

IN YOUR POST.

"I'm talking one panic stop from road speed."

You even quoted it back to me several times in your last few posts.

Just... wow.

Read again. Read it all. Quote it all.

I did.

Are you having problems with the display on your computer or something?

I quoted your ENTIRE post at the top of mine. Then I pointed out one part from it, word for word.

In what language is that "misquoting" you?

Almost every sentence of your post is wrong in some way, here I'll break it down for you-

"The pads do stop the car, as they stop the wheel/tire assembly."

Wrong- The tires stop the car. The pads don't stop anything at all. The pads translate force from the calipers to the rotors. That's all they do.

"The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. "

No, it can't. They do that instantly. They translate the clamping force to the rotors instantly. It's what they do.

Any pads that can engage ABS will do this and provide the same stopping distance.

"The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels."

The pads don't slow down the wheels, the rotors do. The efficiency of the pads DOES change with material, about the only thing in the entire post you are right about, but since both pads generate enough force to engage ABS they are both providing the maximum force that can be used. Pads that transmit a higher amount of force do NOT change stopping distance as that force can not be used by the car.

"The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. "

ABSOLUTELY FALSE. According to me, according to the ABS system designer. According the Brembo. According to Stoptech. Even according to the other folks in this thread.

"There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs."

Again, time does not appear anywhere in the brake force equation. Heat goes largely into the metal of the rotors, the pads aren't "dissipating" anything during the stop... both heated pads and rotors do transfer heat out of them into the air to cool in general though. I'm not even sure what you think you're trying to express there...but the heat has nothing at all to do with stopping distance for one panic stop, because any properly designed OEM system has enough heat capacity to handle it, regardless of pads used.

"Read up."

You're right on the suggestion, you just directed it at the wrong party.

[bartkat]

Sorry bud, but you're wrong about the misquote and wrong about the pads not affecting the braking distance. You're also wrong with your not so veiled personal comments. I refuse to try to discuss anything with a poster such as that. Feel free to continue the repetitive rant though.

[Knightshade]

Sorry bud, but you're wrong about the misquote and wrong about the pads not affecting the braking distance. You're also wrong with your not so veiled personal comments. I refuse to try to discuss anything with a poster such as that.

*rotfl*

Uh...ok. If you refuse to discuss this with someone who knows what the word misquote actually means and has explained in great detail why you're wrong on almost everything you've posted in the thread, has provided source after source explaining why you are wrong, and whom you baselessly called dishonest, I guess I'll just have to struggle through and find some way to continue getting up in the morning.

By the way, pads won't change braking distance in the morning either.

[smooth1]

Knightshade Post #10

The brakes don't stop the car. So long as the pads provide sufficient friction to engage the ABS system different pads can't change braking distance for a given stop.

Bartkat Post# 15

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up.

Anti Lock Braking will only help to maintain vehicle control and will NOT reduce stopping distances in normal driving conditions. It is a fallacy that ABS will make the car stop faster.

Knightshade Post # 16

What stops the car is the force between the road and the tires. Period.

I suggest -you- read up...lemme help

http://www.scirocco.org/faq/brakes/pulpfriction/pfpage1.html

The author has forgotten more about brakes than any 10 guys on here know. He's a world known brake engineer.

Page 3 is where he gets to brake pads... Here's the most relevant parts-

"Ths part might surprise some and offend others, but it is a big misconception that changing brake pad material will magically decrease your stopping distances. In fact, you may have even seen published "data" which attempts to correlate stopping distance to friction coefficient. Although it may appear that there is a relationship between the two, there really isn't, and here's why."

He then goes on the explain why.... later he adds-

"Brake pads with radical changes in coefficient over their operating range are not a racer's best friend. Be sure to select one that remains relatively stable under the operating conditions you are expecting, but don't expect any shorter stopping distances, because the brake pads don't stop the car"

And especially-

"So why change brake pad materials in the first place? Because increasing the coefficient of friction can allow for the use of smaller/fewer caliper pistons and/or will reduce the amount of pedal force that the driver needs to apply in order to generate a given rotor output force."

We're not changing the pistons here though, so that's not relevant. And the amount of input force isn't either, as either pad can engage the ABS system, which means the driver is already applying the maximum possible pedal force.

So, once again, I tell you, it's physically impossible for the two similar pads that both can engage the ABS system to change braking distance by a measurable amount. And so does the author of the article.

Knightshade Post #20

But the pads do NOT make the tires stop faster. It's not possible for them to do so. The -only- thing the pads do is transfer the clamping force of the caliper to the rotor.

Once you are at maximum force, where ABS engages, the ONLY relevant thing to the car stopping is the coefficient of friction between the tires and the road. That's it. Put any brake pad you want on the car and that'll still be true. So any pad that engages ABS will produce the same stopping distance as any other, all else being equal.

Seriously, a guy who has spent most of his life designing and consulting on brakes with companies all over the world wrote that article. He just told you you're wrong, pads don't change braking distance.

Yet you're still arguing about it. Without any sources, evidence, or anything really except insisting none of the facts are true.

Why?

And please, show me some of your 100 sources. Ideally from someone who is NOT trying to sell you their brake pads.

Is this the discussion? the braking distances are solely determined by the tires as the braking components are sufficient enouph to cause wheel lock in an ABS system and therefore the threshold is the tires? Is that where we are right now?

[Knightshade]

That's generally where me, the ABS engineer, Stoptech, Brembo, and others are.

I can't speak to where Barkat is as he appears to live in a universe with different physical laws :P

[smooth1]

Ok, cool, Then what about the new Electronic Wedge braking system that Seimans is developing? It's not new tires, but a system that maximizes the pad and rotor friction ability to create even shorter stopping distances? How can that be then?

The Wedge

[smooth1]

Heres another link that explains it a little more.

More Wedge info

[Knightshade]

Ok, cool, Then what about the new Electronic Wedge braking system that Seimans is developing? It's not new tires, but a system that maximizes the pad and rotor friction ability to create even shorter stopping distances? How can that be then?

The Wedge

Because that isn't a hydraulic brake system like we've been discussing this entire time?

Likewise, backward firing rocket motors in front of the braking car will stop it faster too, but that's not what we've been discussing all these pages either :)

(EWB is a lot more practical for a car though, and is a very cool technology... it's just not on our cars (or virtually any yet))

I'd like to ask you a question though- For the case actually under discussion, in your opinion, who is correct, myself, or barkat?