New pads and rotors on ISF
11-18-08, 05:14 PM
#50
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Brembo brakes seems to = ~$300 an axle for pads and a like amount for rotors. Pay to play.
11-18-08, 06:30 PM
#51
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Ouch. Count me in as 'Willing to Play, but NOT willing to Pay'. Was thinking of trading in my IS350 in a couple years and use it as a down for a used ISF, but was not aware of this type of maintenance (Wow) -> No ISF in the future for me
. Very informative brake threads by the way from different views.
11-18-08, 09:43 PM
#52
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did you see this post btw?
https://www.clublexus.com/forums/sho...isf+brake+pads
Last edited by lexusjunky; 11-18-08 at 09:53 PM.
11-19-08, 03:09 AM
#53
Stop being such a sensationalist. Im not the one dying of laughter and belittling other people. You cant just generalize an environment with multiple systems with specific boundaries for your case. Its obvious I have to break it down for you since you dont understand all of my assumptions.
1.) That the car is equipped with ABS. Yes, modern cars have brakes that perform well enough to engage ABS. But not all do, both road going and especially race cars. On a dry surface, ABS will still be engaged so that the tires static coefficient of friction comes into play and not the tires kinetic coefficient of friction, which is smaller. Like I said before, the brakes will reach their thermal threshold well before a tire will. So, your tires are not going to destroy themselves from simple high speed brake tests. But, there is yet to be a system that, like ABS, actively controls operating temperature of brake systems to maintain its highest coefficient of friction. Here is a link showing how an aftermarket Stoptech brake system performed a little bit better than standard pads: http://www.sportcompactcarweb.com/ro...est/index.html
However, the point was that the aftermarket system was more consistent. They also made the assumption that pad friction coefficients were the same (to draw some conclusions). This is actually the crux of the argument, in the end its about coefficients of friction from tire to road and rotor to pad.
2.) That the sampling for data is more than just one run. You can read up on statistical analysis and why reading only a few runs doesnt give you any information. http://home.ubalt.edu/ntsbarsh/stat-...pics.htm#rwisd
3.) Finally, given this is a high performance car, we would assume the driver will be fully utilizing the car on road or track. You dont just brake once on a track.
As temperature increases in the pad lining, coefficient of friction will decrease beyond the operating temperature. Different materials have not only different coefficients of friction, but also thermal capacitance. There are a few studies to show different materials at different temperatures, showing the coefficient of friction. I have some study links below, since my books do not have these graphs for any materials (they are old). This is why some pads have differing compositions of Cu, Al, and steel. When the coefficient decreases, the amount of force the pad is able to generate (all else being equal) is much reduced.
Here is a paragraph from Pulp Friction, "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!" This sounds oxymoronic. On the one hand, brake pads dont change stopping distances. Yet on the other hand he says choose a pad that has a stable coefficient over a some window of operating temperature. Well which is it? If changing the pad makes no difference, then why bother? If the coefficient changes, rotor torque changes and thus the time it takes to stop changes (all else being equal)!
If you were to slap on some racing pads and went to town, you would notice a need to increase pedal force to obtain the same stopping force compared to regular pads. Likewise with ceramic pads. But being good engineers, you dont just do one run and conclude that ceramics and racing pads are worse than your vanilla pads.
Coefficient of friction from the tire to the road ranges between 0.6 and 0.8. If we were to assume same brake pads, can we predict that stopping distances will change if we used different tires? Yes. We know civilian tires have lower coefficients than an R compound tire. But why? Is it the tread (or lack thereof)? No. Is it the size of the tire? No. Its composition.
Without brake pads your car will not stop. Ok, now Im being sensational, but if tire composition affects braking distances, then brake pad composition (which provides us the opposing force) should as well. Most vanilla pads will have a coefficient of friction from 0.3 to 0.4. Racing pads have a higher coefficient in their operating temperatures, ranging from 0.4 to 0.5 or even higher for the state of the art ceramics (silicon carbides, http://www.edmunds.com/ownership/tec...3/article.html). Higher performance pads will maintain their stopping distances for longer than vanilla pads. Why does every car mag bother to do braking tests beyond the first one? Because brake pads arent just used once, they are used multiple times and pad compositions determine how many times or how long they can give you certain stopping distances.
In the end my point is you cant ignore any system for a complex environment such as this. This is why some people can devote their entire careers to just brake systems (James Walker). But obviously its not so simple to say pad materials have no effect on brake distances. Theres tons of research being done by engineering companies and auto makers and a brief explanation of the results can be read here, the Formula 1 website:
http://www.formula1.com/inside_f1/un...port/5284.html
Pulp Friction reads like a magazine article. I would think his book does better in explaining every aspect of brake systems and Im willing to bet that pad composition gets a lot more words than just a few paragraphs.
More studies relating to pad materials and their effects on brake systems:
http://www.sciencedirect.com/science...47f99f0a46fe7b
http://www.sciencedirect.com/science...73a3236e74feaa
1.) That the car is equipped with ABS. Yes, modern cars have brakes that perform well enough to engage ABS. But not all do, both road going and especially race cars. On a dry surface, ABS will still be engaged so that the tires static coefficient of friction comes into play and not the tires kinetic coefficient of friction, which is smaller. Like I said before, the brakes will reach their thermal threshold well before a tire will. So, your tires are not going to destroy themselves from simple high speed brake tests. But, there is yet to be a system that, like ABS, actively controls operating temperature of brake systems to maintain its highest coefficient of friction. Here is a link showing how an aftermarket Stoptech brake system performed a little bit better than standard pads: http://www.sportcompactcarweb.com/ro...est/index.html
However, the point was that the aftermarket system was more consistent. They also made the assumption that pad friction coefficients were the same (to draw some conclusions). This is actually the crux of the argument, in the end its about coefficients of friction from tire to road and rotor to pad.
2.) That the sampling for data is more than just one run. You can read up on statistical analysis and why reading only a few runs doesnt give you any information. http://home.ubalt.edu/ntsbarsh/stat-...pics.htm#rwisd
3.) Finally, given this is a high performance car, we would assume the driver will be fully utilizing the car on road or track. You dont just brake once on a track.
As temperature increases in the pad lining, coefficient of friction will decrease beyond the operating temperature. Different materials have not only different coefficients of friction, but also thermal capacitance. There are a few studies to show different materials at different temperatures, showing the coefficient of friction. I have some study links below, since my books do not have these graphs for any materials (they are old). This is why some pads have differing compositions of Cu, Al, and steel. When the coefficient decreases, the amount of force the pad is able to generate (all else being equal) is much reduced.
Here is a paragraph from Pulp Friction, "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!" This sounds oxymoronic. On the one hand, brake pads dont change stopping distances. Yet on the other hand he says choose a pad that has a stable coefficient over a some window of operating temperature. Well which is it? If changing the pad makes no difference, then why bother? If the coefficient changes, rotor torque changes and thus the time it takes to stop changes (all else being equal)!
If you were to slap on some racing pads and went to town, you would notice a need to increase pedal force to obtain the same stopping force compared to regular pads. Likewise with ceramic pads. But being good engineers, you dont just do one run and conclude that ceramics and racing pads are worse than your vanilla pads.
Coefficient of friction from the tire to the road ranges between 0.6 and 0.8. If we were to assume same brake pads, can we predict that stopping distances will change if we used different tires? Yes. We know civilian tires have lower coefficients than an R compound tire. But why? Is it the tread (or lack thereof)? No. Is it the size of the tire? No. Its composition.
Without brake pads your car will not stop. Ok, now Im being sensational, but if tire composition affects braking distances, then brake pad composition (which provides us the opposing force) should as well. Most vanilla pads will have a coefficient of friction from 0.3 to 0.4. Racing pads have a higher coefficient in their operating temperatures, ranging from 0.4 to 0.5 or even higher for the state of the art ceramics (silicon carbides, http://www.edmunds.com/ownership/tec...3/article.html). Higher performance pads will maintain their stopping distances for longer than vanilla pads. Why does every car mag bother to do braking tests beyond the first one? Because brake pads arent just used once, they are used multiple times and pad compositions determine how many times or how long they can give you certain stopping distances.
In the end my point is you cant ignore any system for a complex environment such as this. This is why some people can devote their entire careers to just brake systems (James Walker). But obviously its not so simple to say pad materials have no effect on brake distances. Theres tons of research being done by engineering companies and auto makers and a brief explanation of the results can be read here, the Formula 1 website:
http://www.formula1.com/inside_f1/un...port/5284.html
Pulp Friction reads like a magazine article. I would think his book does better in explaining every aspect of brake systems and Im willing to bet that pad composition gets a lot more words than just a few paragraphs.
More studies relating to pad materials and their effects on brake systems:
http://www.sciencedirect.com/science...47f99f0a46fe7b
http://www.sciencedirect.com/science...73a3236e74feaa
From the / Tires -- to the "pads" to the "rotors", to the "calipers" they all work together
Hey, if you put a slice of cheese, in replacement of your current pad it will stop in the same distance right? inducing ABS, or would you have to press that much harder to induce ABS?
11-19-08, 05:56 PM
#54
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So my breaks are just starting to get "squeaky". How long do you guys think before I go in and get them changed?? Not sure what the standard procedure is. Im thinking about just waiting until my 15k check up.
11-19-08, 06:32 PM
#55
F cars require new brakes at 13k miles?! Is that typical or are you guys taking them on the track or driving them really hard? I can't see how Lexus expects customers to pay this kind of price once a year on top of all of the other routine maintenance costs! Are there after market pads available? Dare I say that potential customers will end up giving M3's a look due to the fact that BMW covers all maintenance costs for 4yrs/50k mi including brakes. This is depressing to hear since I was planning to trade in my 250 in the spring... 
11-19-08, 07:06 PM
#56
Lexus Champion
^^I wouldn't worry yet, I don't think the F needs new brakes at 13k. Where's Cathafer, I don't think shes had her brakes replaced yet and she has a ton of miles
How many miles do you have? Have you tracked it lately?
Mine were squeaky at 4k miles and I talked to the dealership and a bunch of people here at CL and found out that if the brakes on the F aren't used to their highest potential, a film builds and you have to take it out and step on them really hard a few times (80-40 hard, 60-20 hard, etc.). The film burns off and no more squeaking!
Mine were squeaky at 4k miles and I talked to the dealership and a bunch of people here at CL and found out that if the brakes on the F aren't used to their highest potential, a film builds and you have to take it out and step on them really hard a few times (80-40 hard, 60-20 hard, etc.). The film burns off and no more squeaking!
11-19-08, 08:16 PM
#57
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^^I wouldn't worry yet, I don't think the F needs new brakes at 13k. Where's Cathafer, I don't think shes had her brakes replaced yet and she has a ton of miles
How many miles do you have? Have you tracked it lately?
Mine were squeaky at 4k miles and I talked to the dealership and a bunch of people here at CL and found out that if the brakes on the F aren't used to their highest potential, a film builds and you have to take it out and step on them really hard a few times (80-40 hard, 60-20 hard, etc.). The film burns off and no more squeaking!
How many miles do you have? Have you tracked it lately?
Mine were squeaky at 4k miles and I talked to the dealership and a bunch of people here at CL and found out that if the brakes on the F aren't used to their highest potential, a film builds and you have to take it out and step on them really hard a few times (80-40 hard, 60-20 hard, etc.). The film burns off and no more squeaking!
No tracking. Im just under 13k miles. Only reason I ask is cuz there was another member who just changed his/her pads at 13k and said the price was outrageous. I'll heat em up and see what happens. I'm not planning on changing them till atleast 15-16k I was just curious if anybody was experiencing the squeaking. Also heard Brembos are notorious for being squeaky but I could be misinformed there as well.
Thanks
11-19-08, 09:42 PM
#58
Lexus Champion
11-19-08, 11:33 PM
#59
Tech Info Resource
iTrader: (2)
Stop being such a sensationalist. Im not the one dying of laughter and belittling other people. You cant just generalize an environment with multiple systems with specific boundaries for your case. Its obvious I have to break it down for you since you dont understand all of my assumptions.
1.) That the car is equipped with ABS. Yes, modern cars have brakes that perform well enough to engage ABS. But not all do, both road going and especially race cars. On a dry surface, ABS will still be engaged so that the tires static coefficient of friction comes into play and not the tires kinetic coefficient of friction, which is smaller. Like I said before, the brakes will reach their thermal threshold well before a tire will. So, your tires are not going to destroy themselves from simple high speed brake tests. But, there is yet to be a system that, like ABS, actively controls operating temperature of brake systems to maintain its highest coefficient of friction. Here is a link showing how an aftermarket Stoptech brake system performed a little bit better than standard pads: http://www.sportcompactcarweb.com/ro...est/index.html
However, the point was that the aftermarket system was more consistent. They also made the assumption that pad friction coefficients were the same (to draw some conclusions). This is actually the crux of the argument, in the end its about coefficients of friction from tire to road and rotor to pad.
2.) That the sampling for data is more than just one run. You can read up on statistical analysis and why reading only a few runs doesnt give you any information. http://home.ubalt.edu/ntsbarsh/stat-...pics.htm#rwisd
3.) Finally, given this is a high performance car, we would assume the driver will be fully utilizing the car on road or track. You dont just brake once on a track.
As temperature increases in the pad lining, coefficient of friction will decrease beyond the operating temperature. Different materials have not only different coefficients of friction, but also thermal capacitance. There are a few studies to show different materials at different temperatures, showing the coefficient of friction. I have some study links below, since my books do not have these graphs for any materials (they are old). This is why some pads have differing compositions of Cu, Al, and steel. When the coefficient decreases, the amount of force the pad is able to generate (all else being equal) is much reduced.
Here is a paragraph from Pulp Friction, "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!" This sounds oxymoronic. On the one hand, brake pads dont change stopping distances. Yet on the other hand he says choose a pad that has a stable coefficient over a some window of operating temperature. Well which is it? If changing the pad makes no difference, then why bother? If the coefficient changes, rotor torque changes and thus the time it takes to stop changes (all else being equal)!
If you were to slap on some racing pads and went to town, you would notice a need to increase pedal force to obtain the same stopping force compared to regular pads. Likewise with ceramic pads. But being good engineers, you dont just do one run and conclude that ceramics and racing pads are worse than your vanilla pads.
Coefficient of friction from the tire to the road ranges between 0.6 and 0.8. If we were to assume same brake pads, can we predict that stopping distances will change if we used different tires? Yes. We know civilian tires have lower coefficients than an R compound tire. But why? Is it the tread (or lack thereof)? No. Is it the size of the tire? No. Its composition.
Without brake pads your car will not stop. Ok, now Im being sensational, but if tire composition affects braking distances, then brake pad composition (which provides us the opposing force) should as well. Most vanilla pads will have a coefficient of friction from 0.3 to 0.4. Racing pads have a higher coefficient in their operating temperatures, ranging from 0.4 to 0.5 or even higher for the state of the art ceramics (silicon carbides, http://www.edmunds.com/ownership/tec...3/article.html). Higher performance pads will maintain their stopping distances for longer than vanilla pads. Why does every car mag bother to do braking tests beyond the first one? Because brake pads arent just used once, they are used multiple times and pad compositions determine how many times or how long they can give you certain stopping distances.
In the end my point is you cant ignore any system for a complex environment such as this. This is why some people can devote their entire careers to just brake systems (James Walker). But obviously its not so simple to say pad materials have no effect on brake distances. Theres tons of research being done by engineering companies and auto makers and a brief explanation of the results can be read here, the Formula 1 website:
http://www.formula1.com/inside_f1/un...port/5284.html
Pulp Friction reads like a magazine article. I would think his book does better in explaining every aspect of brake systems and Im willing to bet that pad composition gets a lot more words than just a few paragraphs.
More studies relating to pad materials and their effects on brake systems:
http://www.sciencedirect.com/science...47f99f0a46fe7b
http://www.sciencedirect.com/science...73a3236e74feaa
1.) That the car is equipped with ABS. Yes, modern cars have brakes that perform well enough to engage ABS. But not all do, both road going and especially race cars. On a dry surface, ABS will still be engaged so that the tires static coefficient of friction comes into play and not the tires kinetic coefficient of friction, which is smaller. Like I said before, the brakes will reach their thermal threshold well before a tire will. So, your tires are not going to destroy themselves from simple high speed brake tests. But, there is yet to be a system that, like ABS, actively controls operating temperature of brake systems to maintain its highest coefficient of friction. Here is a link showing how an aftermarket Stoptech brake system performed a little bit better than standard pads: http://www.sportcompactcarweb.com/ro...est/index.html
However, the point was that the aftermarket system was more consistent. They also made the assumption that pad friction coefficients were the same (to draw some conclusions). This is actually the crux of the argument, in the end its about coefficients of friction from tire to road and rotor to pad.
2.) That the sampling for data is more than just one run. You can read up on statistical analysis and why reading only a few runs doesnt give you any information. http://home.ubalt.edu/ntsbarsh/stat-...pics.htm#rwisd
3.) Finally, given this is a high performance car, we would assume the driver will be fully utilizing the car on road or track. You dont just brake once on a track.
As temperature increases in the pad lining, coefficient of friction will decrease beyond the operating temperature. Different materials have not only different coefficients of friction, but also thermal capacitance. There are a few studies to show different materials at different temperatures, showing the coefficient of friction. I have some study links below, since my books do not have these graphs for any materials (they are old). This is why some pads have differing compositions of Cu, Al, and steel. When the coefficient decreases, the amount of force the pad is able to generate (all else being equal) is much reduced.
Here is a paragraph from Pulp Friction, "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!" This sounds oxymoronic. On the one hand, brake pads dont change stopping distances. Yet on the other hand he says choose a pad that has a stable coefficient over a some window of operating temperature. Well which is it? If changing the pad makes no difference, then why bother? If the coefficient changes, rotor torque changes and thus the time it takes to stop changes (all else being equal)!
If you were to slap on some racing pads and went to town, you would notice a need to increase pedal force to obtain the same stopping force compared to regular pads. Likewise with ceramic pads. But being good engineers, you dont just do one run and conclude that ceramics and racing pads are worse than your vanilla pads.
Coefficient of friction from the tire to the road ranges between 0.6 and 0.8. If we were to assume same brake pads, can we predict that stopping distances will change if we used different tires? Yes. We know civilian tires have lower coefficients than an R compound tire. But why? Is it the tread (or lack thereof)? No. Is it the size of the tire? No. Its composition.
Without brake pads your car will not stop. Ok, now Im being sensational, but if tire composition affects braking distances, then brake pad composition (which provides us the opposing force) should as well. Most vanilla pads will have a coefficient of friction from 0.3 to 0.4. Racing pads have a higher coefficient in their operating temperatures, ranging from 0.4 to 0.5 or even higher for the state of the art ceramics (silicon carbides, http://www.edmunds.com/ownership/tec...3/article.html). Higher performance pads will maintain their stopping distances for longer than vanilla pads. Why does every car mag bother to do braking tests beyond the first one? Because brake pads arent just used once, they are used multiple times and pad compositions determine how many times or how long they can give you certain stopping distances.
In the end my point is you cant ignore any system for a complex environment such as this. This is why some people can devote their entire careers to just brake systems (James Walker). But obviously its not so simple to say pad materials have no effect on brake distances. Theres tons of research being done by engineering companies and auto makers and a brief explanation of the results can be read here, the Formula 1 website:
http://www.formula1.com/inside_f1/un...port/5284.html
Pulp Friction reads like a magazine article. I would think his book does better in explaining every aspect of brake systems and Im willing to bet that pad composition gets a lot more words than just a few paragraphs.
More studies relating to pad materials and their effects on brake systems:
http://www.sciencedirect.com/science...47f99f0a46fe7b
http://www.sciencedirect.com/science...73a3236e74feaa
Let's see - pads don't turn to liquid before the tires do, so clearly the pads have an influence on stopping distance. Yes, TIRES TURN TO LIQUID when you lock the brakes. Why do you think they leave those wonderful black marks? Why does stopping distance go nearly infinite when the wheel locks because the pad easily overcomes the tire's ability to resist?
I'm really done here. If you really think you're going to change stopping distance on a street car with a pad change, you've obviously never done any real tests. Continue on with your conjecture.
11-19-08, 11:37 PM
#60
Tech Info Resource
iTrader: (2)
Kinda like sticking a tube on your intake and calling it better when the ports in the head won't flow any more no matter how big the pipe on the intake is. But again, that's REAL WORLD stuff. Wouldn't want to confuse it with marketing hype because we know if K&N claims 6 hp it must be true.
