ame03 Posted July 1, 2008 Posted July 1, 2008 I have read something about this before but i'm not very clear about it. can some one clarify about the brake pad dust issue they had i have to go back for the 1000 mi service this weekend and i would like to know if i need them to change my brake pads? i do notice a lot of dust comming out of the brake pads also is this done for free? '08 IS 250 thanks
Knightshade Posted July 1, 2008 Posted July 1, 2008 I have read something about this before but i'm not very clear about it. can some one clarify about the brake pad dust issue they hadi have to go back for the 1000 mi service this weekend and i would like to know if i need them to change my brake pads? i do notice a lot of dust comming out of the brake pads also is this done for free? '08 IS 250 thanks It is done for free on 06 and 07 models. The TSIB only covers those years, despite the 08s having the same problem. Your dealership MIGHT do it anyway for you as a courtesy, or they might not, you'd have to ask. And yes the 'fix' is changing the pads to an alternative pad they offer that is low dust but stops just as well.
PA350 Posted July 1, 2008 Posted July 1, 2008 I've read people waiting until 20k or so to replace. I'm probably going to do at my 15k service.
CrunchySkippy Posted July 1, 2008 Posted July 1, 2008 I've read people waiting until 20k or so to replace. I'm probably going to do at my 15k service. I guess it really depends on how long you can put up with the excessive brake dust. But honestly, if it doesn't bother you - you may as well wait and get more miles out of the originals. I had mine replaced as soon as it was convenient to get back to the dealer.
jules8174 Posted July 1, 2008 Posted July 1, 2008 it was done for free on my 08 and makes a HUGE difference
terry993 Posted July 2, 2008 Posted July 2, 2008 I had the TSB dust fix done under warranty. No dust now, but my subjective impression is my stopping distance is not as good.
Knightshade Posted July 2, 2008 Posted July 2, 2008 I had the TSB dust fix done under warranty. No dust now, but my subjective impression is my stopping distance is not as good. If you measure it you'll find your impression is not correct. The brake pedal travel/effort is more linear though, which might be what is making you think that. The brakes stop the car exactly as well as they did before though.
BaddBoi70 Posted July 2, 2008 Posted July 2, 2008 I had the TSB dust fix done under warranty. No dust now, but my subjective impression is my stopping distance is not as good. If you measure it you'll find your impression is not correct. The brake pedal travel/effort is more linear though, which might be what is making you think that. The brakes stop the car exactly as well as they did before though. I agree with Knightshade. I had the front pads replaced (covered under the TSIB) on my 06 IS 350 and I was told by the service manager that my braking ability would be "comprimised" by as much as 30%! I just laughed at him and politely asked him to replace the pads :) I have seen a very slight difference, maybe 2 or 3%, but that is a FAR cry from the 30% claim from the service manager.
bartkat Posted July 5, 2008 Posted July 5, 2008 Anybody got comparative data on those stopping distance claims?
Knightshade Posted July 5, 2008 Posted July 5, 2008 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 Posted July 5, 2008 Posted July 5, 2008 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. No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP.
Knightshade Posted July 5, 2008 Posted July 5, 2008 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. No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP. No, it's an understanding of physics. It would be impossible for it change the braking distance because the pads are not what stop the vehicle. It'd be like you asking me to provide data to "prove" that stickers don't add horsepower.
bartkat Posted July 5, 2008 Posted July 5, 2008 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. No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP. No, it's an understanding of physics. It would be impossible for it change the braking distance because the pads are not what stop the vehicle. It'd be like you asking me to provide data to "prove" that stickers don't add horsepower. Stopping power isn't just about clamping down on the disks with just anything that will grab them. If that were the case then the optimum would be carbon-carbon pads and rotors. Better yet stick a broom handle in the spokes and stop even faster. And no, I didn't ask you to prove a negative. Perhaps this or some of the other articles from a Google search will help you gain a better understanding of the factors related to brake pads and stopping ability. We want our vehicle's brake system to offer smooth, quiet braking capabilities under a wide range of temperature and road conditions. We don't want brake-generated noise and dust annoying us during our daily driving.To accommodate this, brake friction materials have evolved significantly over the years. They've gone from asbestos to organic to semi-metallic formulations. Each of these materials has proven to have advantages and disadvantages regarding environmental friendliness, wear, noise and stopping capability. http://www.tirerack.com/brakestechpage-1/88.shtml The last factor than determines the total stopping distance is the cars braking capability which depends on factors such as; * the type of braking system, * brake pad material, * brake alignment, * tyre pressures, * tyre tread and grip, * vehicle weight, * suspension system, * the co-efficient of friction of the road surface, * wind speed, * slope of road, * surface smoothness * the braking technique applied by the driver. http://www.sdt.com.au/safedrive-directory-...INGDISTANCE.htm In the modern vehicle, the wheel brake is challenged to contribute to a great many vehicle driving conditions extending way beyond just stopping the car. The friction material is a very key element in this. To maintain the optimum performance, it is important to understand the implications of the choices that are being offered to consumers and help them make an educated decision. http://www.bendix.com.au/ABSESCReplacementBrakePads.aspx 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.If you are not able to get the tires to that point of eminent lockup, then there is a couple of possibilities. The main one being the brake pad composition. The brake pads are what impart the friction to the brake rotors. If the pads are not able to grip the rotors aggressively, then the vehicle will not decelerate correctly. http://ford.justanswer.com/questions/19ypo...erceptor-failed
Knightshade Posted July 5, 2008 Posted July 5, 2008 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.
bartkat Posted July 5, 2008 Posted July 5, 2008 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. 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 Posted July 5, 2008 Posted July 5, 2008 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. 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.
bartkat Posted July 5, 2008 Posted July 5, 2008 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. 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. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen.
Knightshade Posted July 5, 2008 Posted July 5, 2008 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. 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. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen. So you have nothing to actually dispute the professional brake engineer I quoted. Gotcha. As an aside, I encourage everyone to read that article, it dispells a lot of common misconceptions about brakes... especially good for the folks who think "drilling" is a good idea for rotors too.
bartkat Posted July 5, 2008 Posted July 5, 2008 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. 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. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen. So you have nothing to actually dispute the professional brake engineer I quoted. Gotcha. As an aside, I encourage everyone to read that article, it dispells a lot of common misconceptions about brakes... especially good for the folks who think "drilling" is a good idea for rotors too. I encourage you to read 100 other articles by 100 other experts. Your guy is playing with semantics while you parrot the same. So, back to the black art of friction materials. While a "coefficient of friction" number is a nice data point to consider when modifying a braking system, what is even more important is the ability of the material to maintain that coefficient under a variety of driving conditions. You guy says wind is a factor. Will a 50MPH wind stop your car faster than a 10MPH wind? Same thing goes for pads. The quicker they get your tires to stop, the quicker your car stops. Argue with that point all you want mr expert. BTW: There's data that shows different stopping distances with different pads. I have yet to see any data in your presentation.
Knightshade Posted July 5, 2008 Posted July 5, 2008 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. 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. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen. So you have nothing to actually dispute the professional brake engineer I quoted. Gotcha. As an aside, I encourage everyone to read that article, it dispells a lot of common misconceptions about brakes... especially good for the folks who think "drilling" is a good idea for rotors too. So, back to the black art of friction materials. While a "coefficient of friction" number is a nice data point to consider when modifying a braking system, what is even more important is the ability of the material to maintain that coefficient under a variety of driving conditions. You guy says wind is a factor. Will a 50MPH wind stop your car faster than a 10MPH wind? Same thing goes for pads. The quicker they get your tires to stop, the quicker your car stops. Argue with that point all you want mr expert. 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.
Knightshade Posted July 5, 2008 Posted July 5, 2008 Since you seem to want a test of what we already know is true though, here's a guy who did it- http://www.clublexus.com/forums/showthread.php?t=290476 Read post number 7.... even better, lemme quote part of his explanation for why he got identical braking distance with both sets of pads- "Another thing to remember is that the brakes can only effectively stop the car as long as the tires don't loose traction (lock up) and the ABS is going to do this for you, so realistically the only thing in question here is the ability of the brake pad to clamp the rotor tight enough to make the wheel lock and it does that just as effectively as the original pad does" Gee, that sounds familiar. He goes on to add that for road racing/tracking you might see fade sooner with the new pads, but not in street use. Huh, that sounds kinda familiar too...
bartkat Posted July 5, 2008 Posted July 5, 2008 I read your article, but it appears you didn't read mine. Are you really saying that the time it takes a "clamping" pad to slow the wheel/tire assembly doesn't make any difference in stopping distance? Remember at a given speed, time = distance. Would you say that the fact that pad x brings the wheel to a stop in less time than pad y makes no difference? If you do, you're just wrong. Even your expert points out that the effiency of each component in the system has an effect.
Tango Posted July 5, 2008 Posted July 5, 2008 I read your article, but it appears you didn't read mine.Are you really saying that the time it takes a "clamping" pad to slow the wheel/tire assembly doesn't make any difference in stopping distance? Remember at a given speed, time = distance. Would you say that the fact that pad x brings the wheel to a stop in less time than pad y makes no difference? If you do, you're just wrong. Even your expert points out that the effiency of each component in the system has an effect. You're wrong Knightshade, because you're not taking into consideration the time it takes to apply sufficient friction up to the point that ABS activates or without ABS when the discs stop wheel rotation. As a matter of interest I changed the high friction pads on my IS250 for a set of the ceramic based material, but recognising the reason why they were on originally ("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.") I also upgraded my calipers and rotors...more pistons and bigger diameter rotors. As a result my brakes are a lot less grabby when a small amount of pedal force is applied, and bring the rotors up to the point of ABS activation a lot quicker when a large amount of pedal force is applied.
Knightshade Posted July 5, 2008 Posted July 5, 2008 I'm pretty sure changing the rotors, and calipers, and pads all at the same time isn't a real useful case for proving the pads by themselves change anything. Barkat- what article of yours did I not read? I've still yet to see you post one. - Wait, my bad, you went back and edited your old posts with links after the fact- I'll go look at those now The Pulp Friction article pretty clearly explains where you -can- see improvements from different pads... But stopping distance is NOT one of those areas, and it's quite clear about that. When I posted reference to someone having actually TESTED the two pads, they not only found results that -exactly- matched what I'm saying, they explained it using the exact same reasoning I'm using. So on my side we have: The actual facts. A world renowned brake systems engineer who says exactly what I'm saying. A number of pretty technically respected other forum users on CL who all agree with me (Lance Wolrab and Genby among them) On your side we have: You and one other forum user who insist it can't be true. But I understand... it's like arguing with the guys who insist "drilling" rotors is a good idea for a street car... no matter how much science you explain to them, they'll insist they're right. But go re-read page 5 of the article... where he explains that there are 4 areas you CAN impact by making brake system changes like different pads, larger rotors, etc... None of those areas is stopping distance though.
Knightshade Posted July 5, 2008 Posted July 5, 2008 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. No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP. No, it's an understanding of physics. It would be impossible for it change the braking distance because the pads are not what stop the vehicle. It'd be like you asking me to provide data to "prove" that stickers don't add horsepower. Stopping power isn't just about clamping down on the disks with just anything that will grab them. If that were the case then the optimum would be carbon-carbon pads and rotors. Better yet stick a broom handle in the spokes and stop even faster. And no, I didn't ask you to prove a negative. Perhaps this or some of the other articles from a Google search will help you gain a better understanding of the factors related to brake pads and stopping ability. We want our vehicle's brake system to offer smooth, quiet braking capabilities under a wide range of temperature and road conditions. We don't want brake-generated noise and dust annoying us during our daily driving.To accommodate this, brake friction materials have evolved significantly over the years. They've gone from asbestos to organic to semi-metallic formulations. Each of these materials has proven to have advantages and disadvantages regarding environmental friendliness, wear, noise and stopping capability. http://www.tirerack.com/brakestechpage-1/88.shtml The last factor than determines the total stopping distance is the cars braking capability which depends on factors such as; * the type of braking system, * brake pad material, * brake alignment, * tyre pressures, * tyre tread and grip, * vehicle weight, * suspension system, * the co-efficient of friction of the road surface, * wind speed, * slope of road, * surface smoothness * the braking technique applied by the driver. http://www.sdt.com.au/safedrive-directory-...INGDISTANCE.htm In the modern vehicle, the wheel brake is challenged to contribute to a great many vehicle driving conditions extending way beyond just stopping the car. The friction material is a very key element in this. To maintain the optimum performance, it is important to understand the implications of the choices that are being offered to consumers and help them make an educated decision. http://www.bendix.com.au/ABSESCReplacementBrakePads.aspx 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.If you are not able to get the tires to that point of eminent lockup, then there is a couple of possibilities. The main one being the brake pad composition. The brake pads are what impart the friction to the brake rotors. If the pads are not able to grip the rotors aggressively, then the vehicle will not decelerate correctly. http://ford.justanswer.com/questions/19ypo...erceptor-failed None of those links say that changing pads change stopping distance. The ford link is about ABS, which isn't the topic... the only mention of brake pads is they need to be capable of engaging ABS- WHICH WAS EXACTLY WHAT I TOLD YOU. If they can engage ABS they'll exert the maximum possible braking force. The Bendix link doesn't mention braking distance -at all- It does mention performance, which could be relevant to repeated frequent braking like at the track.... the one place I mentioned pads CAN matter because you want a consistent coeeficient of friction across multiple frequent stops.... so once again it AGREES WITH ME AND SAYS NOTHING ABOUT YOUR POINT. The SDT link is incredibly vague... it lists brake pads along with 10 other things (including the wind you're a big fan of).... but doesn't say why any of them matter. Once again, pads so worn they can not engage the ABS system or otherwise apply maximum braking force certainly CAN impact braking performance. But that isn't the topic. We're comparing two brake pads that both can do that. And the tirerack link mentions noise, dust, and smoothness...and pads certainly can change those. It says nothing about braking distance. Seriously, if you were correct, you'd think you could find one reliable source that actually says what you are saying. Ideally one that explains the science behind it. You know, kinda like my article does for 5 pages in great depth saying you're wrong. The only folks I've seen say it are people selling brake pads...or people who wasted money on em and want to justify their purchase.
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