How to fix brake dust on IS 250?
08-11-12, 09:57 AM
#16
I'm in Canada, and my dealership says they don't change the pads out to the low dust ones unless they are being replaced under warranty for defective pads. Not sure if I believe that but that's what the deal was when I called.
Brake pads that dusts more are generally considered higher performance pads, the trade off of making a low dust pad is the decrease in initial bite, especially when cold, and overall braking power given the same applied pedal pressure, and increased rotor wear.
Brake pads that dusts more are generally considered higher performance pads, the trade off of making a low dust pad is the decrease in initial bite, especially when cold, and overall braking power given the same applied pedal pressure, and increased rotor wear.
It can change the "feel" of the brakes, but not the stopping distance of the car.
Personally I find the feel of the low-dust pads much superior to the high-dust ones, because you have a broader range in which to modulate braking, rather than the on/off-switch feel of the high-dust brakes....but again both will stop the car in exactly the same distance when you need them to.
If you want to stop any shorter you need better tires, not better brakes.
For track use I wouldn't really recommend either pad- especially with how easy pads are on the 2IS to swap... I suggest a dedicated set of track pads for track use, and the low-dust OEM pads for street use.
09-26-12, 06:29 PM
#21
Does the feel of brake any different between Lexus low-dust and high-dust pads?
I mean when you apply the brake. Characteristic such as initial bite, brake force prgressiveness, brake force modulation, brake paddle feel, paddle firmness, smoothness, rotor wear ...
I mean when you apply the brake. Characteristic such as initial bite, brake force prgressiveness, brake force modulation, brake paddle feel, paddle firmness, smoothness, rotor wear ...
Last edited by SCWB; 09-26-12 at 06:34 PM.
09-26-12, 09:38 PM
#22
The low dust-pad feels linear so you can control the braking power. The high-dust one is harder to control to some drivers because it's more like a progressiveness.
Braking power wise and stopping distance is the same.
09-27-12, 08:36 PM
#23
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That's 100% incorrect. Changing to a different brake pad compound can make a huge impact on stopping power.
09-28-12, 05:33 AM
#24
No, it's not.
First, I didn't say "stopping power" I said "stopping distance"
Which can't change with a pad change.
If you think it can you fundamentally do not understand how and why a car stops.
I suggest you read this article before trying to discuss the matter any further, or you'll just embarrass yourself further-
http://www.scirocco.org/faq/brakes/p...n/pfpage1.html
The author is an world reknowned brake engineer who has worked for a number of major OEMs including Stoptech, teaches SAE courses on brake system design, and has literally written books on the topic.
He agrees with me, not you.
(If you don't like him for some reason I can find you similar info from Stoptech, Brembo, Car and Driver, the National Law Enforcement Equipment Testing Center, and numerous other sources, all agreeing with me- this topic has come up more than a few times before)
On any modern vehicle whose stock brakes can engage ABS Changing your pads can change:
The 'feel' of the brakes
The service life of the pads and other brake parts
The amount of dust produced by the brakes
The resistance to fade (which is irrelevant in street use, but matters on a race track)
What it can not do is make the car stop any shorter than it did with the original pads.
If you want to stop shorter you need better tires not better brakes. The tires are what stop the car, and they are what limit your braking distance.
09-30-12, 08:53 PM
#25
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Yes, by changing to a different brake pad compound, you will change your stopping distance. I don't need to read some random article about brakes, I know how they work. I've used many different brake pads on the same vehicle and same tires and they will change your stopping distance dramatically. Go install a set of Carbotech XP20 pads and Hoosier R6 tires on your car and let me know how it stops. Then change the pads to Lexus OEM low dust pads and let me know how it stops. I'm not going to argue about this any further because it's a waste of time and you obviously don't understand.
10-01-12, 06:20 AM
#26
No, you won't.
If you think you will then you don't undestand how brakes work.
Apparently you do since your knowledge is so wrong on the topic.
It's not a random article BTW, it's by a guy who designs braking systems for a living, and has literally written books on the subject.
He teaches SAE master classes on the topic.
http://www.sae.org/training/seminars/actar/
He knows WAY more than you do on the topic.
And he also says you're wrong.
He explains each individual part of the braking system, and then explains why "upgrading" that part won't stop your car any shorter.
It's really a great article to educate folks who know a lot less than they think about how and why brakes work, you'd benefit by reading it.
No, you obviously don't.
Not really, no... as I said before, as long as the brakes can enagage ABS, it's physically impossible for "better" brakes to stop you any shorter... because the tire is incapable of using any more "force"
You'd understand that if you'd read the article I provided.
Or go look up the testing done on the PCCB system for Porsche- it's a $10,000 brake upgrade. And it doesn't change stopping distance. Because it can't.
Or go look up the mathematical formula for vehicle stopping distance.
Here, lemme save you the google time-
d = V2/(2g(f + G))
Where:
d = Braking Distance (ft)
g = Acceleration due to gravity (32.2 ft/sec2)
G = Roadway grade as a percentage; for 2% use 0.02
V = Initial vehicle speed (ft/sec)
f = Coefficient of friction between the tires and the roadway
it asks about the coefficient of friction between the tire and roadway.
it does not ask about the friction of your brake pads.
because they're not relevant.
Go install a set of Carbotech XP20 pads and Hoosier R6 tires on your car and let me know how it stops. Then change the pads to Lexus OEM low dust pads and let me know how it stops. I'm not going to argue about this any further because it's a waste of time and you obviously don't understand.
No need, since I actually understand the topic.
Believe me, every few months someone who doesn't understand braking like you comes along and brings this up again- and every few months me or one of the other guys who understands the topic has to correct em.... I've got all this stuff bookmarked by now so I don't have to look all the sources up again
Here's some more folks who also, unlike you, understand the topic-
Brembo:
http://www.brembo.com/ENG/HighPerformance-Brakes/FAQs/
Where can I find test data on stopping distances?
At the speeds that stopping distance is generally measured from (60 to 70mph), the test is primarily testing the tire's grip on the pavement. As delivered from the manufacturer, nearly all vehicles are able to engage the ABS or lock the wheels at these speeds. Therefore, an increase in braking power will do nothing to stop the vehicle in a shorter distance.
At the speeds that stopping distance is generally measured from (60 to 70mph), the test is primarily testing the tire's grip on the pavement. As delivered from the manufacturer, nearly all vehicles are able to engage the ABS or lock the wheels at these speeds. Therefore, an increase in braking power will do nothing to stop the vehicle in a shorter distance.
And you'd think a company that sells brake upgrades would be first in line to tell you they shorten stopping distance if they actually did so... but they can't, because they don't.
Or how about stoptech?
http://www.stoptech.com/tech_info/wp...lections.shtml
"The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use"
And again you'd think a company that sells brake upgrades would be first in line to tell you they shorten stopping distance if they actually did so... but they can't, because they don't.
Or how about the National Law Enforcement Testing Center that does brake tests for police equipment?
http://www.justnet.org/Lists/JUSTNET...kePads2000.pdf
Here they explain why they don't bother offering test results between different brake pads and systems for a single normal panic stop-
"When braking to a targeted deceleration rate, where the speed of the vehicle at brake application is the same, the stopping distance should also theoretically be the same, making any measurement of stopping distances irrelevant"
Sound familiar?
Car and Driver-
http://www.caranddriver.com/features/08q3/the_power_to_stop-tech_stuff/performance_cars_page_4[/url]
The 911 with the PCCB system performed about the same as the other 911 and the Vette. The average stopping distances of the two 911s were within a foot of each other (305 feet), not surprising since both cars were wearing the same tires.
Another key factor is a short stopping distance—the length of road needed to slow down the car. That’s why we measure 70-mph-to-zero performance on all vehicles we test. But every car has brakes strong enough for the anti-lock system to hold its tires on the verge of lockup for at least one stop. So when a vehicle’s brakes are cold, the stopping distance is more dependent on the traction of the tires than the power of the brakes.
And revisiting the Porsche PCCB thing-
http://www.europeancarweb.com/tech/0...eramic_brakes/
Originally Posted by European Car
The car's best 60 to 0 braking distance with stock brakes rounded to 112 ft (our standard braking data procedure), and its best distance rounded to 113 ft with PCCB. In both cases, performance was consistent within a few feet over five stops, with no fade
Or, from the original article I pointed you to-
Originally Posted by James Walker, Jr
As the brake pedal force is gradually increased, the deceleration rate will also increase until the point at which the tires lock. Beyond this point, additional force applied to the brake pedal does nothing more than make the driver's leg sore. The vehicle will continue to decelerate at the rate governed by the coefticient of friction between the tires and the road....
... You can take this one to the bank. Regardless of your huge rotor diameter, brake pedal ratio, magic brake pad material, or number of pistons in your calipers, your maximum deceleration is limited every time by the tire to road interface. That is the point of this whole article. Your brakes do not stop your car. Your tires stop the car. So while changes to different parts of the brake system may affect certain characteristics or traits of the system's behavior, using stickier tires is ultimately the only sure-fire method of decreasing stopping distances.
... You can take this one to the bank. Regardless of your huge rotor diameter, brake pedal ratio, magic brake pad material, or number of pistons in your calipers, your maximum deceleration is limited every time by the tire to road interface. That is the point of this whole article. Your brakes do not stop your car. Your tires stop the car. So while changes to different parts of the brake system may affect certain characteristics or traits of the system's behavior, using stickier tires is ultimately the only sure-fire method of decreasing stopping distances.
It's almost like they all know the same thing I do... and you thus far do not.
So long as the OEM brakes are capable of locking the wheels or engaging ABS (and virtually any production car made in at least the last few decades this is true for) then upgrading your brakes won't reduce your stopping distance.
That's not to say you can't find an old pinto with crappy brakes and throw some modern track-only race tires on it and be UNABLE to lock the tires with the stock brakes (which IS a case where a brake upgrade will stop the car shorter)... but it's certainly not the case we're discussing here.... on a modern Lexus with OEM brakes that are more than capable of locking up any street tire you put on it... in which case "better" pads won't do a thing to stop you any shorter. They can't.
Because the brakes don't stop the car, the tires do.
Anyone who tells you differently either doesn't understand brakes or is trying to sell you some.
Now, my advice? Go read the pulp friction article and educate yourself on braking...
But if you refuse and want to continue to try and argue the topic, I humbly suggest 2 things:
1) Go search on the previous threads where the other failed arguments like yours happened so you're not just rehashing the things others have already soundly disproven
2) Respond with facts and sources (though you'll have trouble finding those since you're wrong) rather than just "I know better than this long list of braking experts! I've owned 3 different cars that all had brakes! One even had a lot of hp!" which is usually where the discussion goes when folks won't admit they're wrong on the subject but have nothing substantive to support their own point.
Lastly, I apologize if you find the tone of any of the above harsh... but you're not the first person who has had to be educated on this stuff... or the 10th for that matter... and I gave you the opportunity to read the GRM article and correct your information in the first place after all, you chose not to even bother reading it to see if you might be wrong, so I was forced to correct you in greater detail.
Last edited by Kurtz; 10-01-12 at 06:41 AM.
10-29-13, 07:15 PM
#29
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Or try Armour All Wheel Protectant:
http://www.armorall.com/products/vie...?product_id=33
This stuff is legit, I can vouch for it. You can drive two weeks with minimal brake dust on your wheels. Another great thing is it repels road grime as well. Two birds, one stone, and it's cheap. Don't believe me, search up some youtube videos.
http://www.armorall.com/products/vie...?product_id=33
This stuff is legit, I can vouch for it. You can drive two weeks with minimal brake dust on your wheels. Another great thing is it repels road grime as well. Two birds, one stone, and it's cheap. Don't believe me, search up some youtube videos.
