sloted rotors

[Civic Accord Honda]

do sloted rotors really make a difrence? my stock rotors are worn out and i need new ones but dont know if i should get sloted or not and how much xtra are sloted and is it worth it

[Pico]

if you're going to get rid of the car, just go and get the cheap rotors and pads for it, but if you plan on keeping it then get the good rotors for it

[86AccordLxi]

Actually it doesn't matter. Have you ever come close to overheating the brakes? Probably not. If you're really concerned get a semi-decent set of pads and call it.

Alex

[Civic Accord Honda]

yeah we are keeping it for some time now......it dose not need pads yet but the rotor are worn down and the car shakes a whole lot when we push the brakes

[Venyix]

Personally I overheat my brakes sometimes coming off the interstate...might be too fast driving...but as soon as I get the money I'm definitely going slotted/cross drilled.

[87LXiR]

Im actually saving up money to upgarde my brake system and am gonna buy slotted. Reason being the other day i braked from a pretty high speed and experienced some fade not to mention a weird pedal feel. I think its good insurance if you tend to drive at higher than posted speeds or if you ride your brakes alot. if not blanks, a good set of pads and good brake fluid will do you well.

[2ndGenGuy]

Brake fade can be reduced a huge amount just by changing out your brake fluid. Get something with a higher boiling point, a synthetic is the best way to go. If you're going to really spend big bucks on your brakes, you might as well spend some money on your fluid and pick up some Castrol SRF. It's $90 for a bottle, but it's wet boiling point is about the same as it is dry.

If you want something effective without the cost, I hear that Motul 600 is about the best you're going to get. I haven't done a brake fluid swap myself yet, but after doing some serious heat cycling on my rotors, I did some research. And some brake experts I spoke to said this was hugely important. It's the next upgrade coming to my brake system.

[87LXiR]

Brake fade can be reduced a huge amount just by changing out your brake fluid. Get something with a higher boiling point, a synthetic is the best way to go. If you're going to really spend big bucks on your brakes, you might as well spend some money on your fluid and pick up some Castrol SRF. It's $90 for a bottle, but it's wet boiling point is about the same as it is dry.
If you want something effective without the cost, I hear that Motul 600 is about the best you're going to get. I haven't done a brake fluid swap myself yet, but after doing some serious heat cycling on my rotors, I did some research. And some brake experts I spoke to said this was hugely important. It's the next upgrade coming to my brake system.

Good info dude thanks. Im sure your right about the fluid causing fade cause when i experienced it the pedal gradually went higher as i held it and it had a spongy feel to it (Probly cause my fluid was boiling at that point :slap: ). Yeah i was planning on getting the motul fluid also along with ss brake lines and rotors.

[ZackieDarko]

your car shakes when you get on the brakes because the rotors are warped

since it does not rain a whole lot in cali just get regular blanks (slots are to get water away from the contact area so you can stop faster) with some HAWK pads and you will stop just fine

[Civic Accord Honda]

my rotors are warped and have graves in them i tuched the midels of it and slid my finger on it and it cut my fenger open :(

[russiankid]

If you are going to replace your rotors replace your pads as well. I personally don't think you need slotted rotors.

[86AccordLxi]

No, it's not rotors warping, it's an uneven transfer layer of friction pad material.

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Alex

[MessyHonda]

well i have sloted and dimpled in the front......and drilled and sloted in the back. i like the way it feels....i would just get regular with some good AEM pads. i have dot 4 fluid and i dont have any fade or anything.....even if i overheat them.....like doing 100mph stops....they still grip fine.

[2ndGenGuy]

No, it's not rotors warping, it's an uneven transfer layer of friction pad material.

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Alex


Sometimes thats the case. But I think for most passenger cars this is wrong. This guy with Stoptech runs only high end brakes, of course those won't warp. Toss a set of cheap rotors onto a race car and watch what happens. I believe that passenger car rotors DO warp. The runout is measurable, and it doesn't make sense that uneven brake deposits cause a nice smooth wave across a rotors surface.

However, some shimmy is caused by brake pad deposits, but that can be worked out easily. A few 80mph to 30mph hard threshold stops should do it. Do NOT stop your car with the pads and rotors heated up or you definitey will leave deposits.

You should get in one or two good runs with some brake fade. If you do then that should be enough heat cycling to get the uneven deposits broken down. Don't do this too much or else you can glaze your pad.

As for your brakes, Messy, if you do about 4 or 5 of those 100mph stops in a row, they will begin to fade and it will be noticeable. If you're not getting brake fade, you're not stopping as hard as you think. Drilling and slotting doesn't really do much on rotors as tiny as ours. Even top end race cars experience brake fade. In town driving and the occasional hoonage on the street is typically not enough to tell the difference between decent brakes and really good brakes.

[MessyHonda]

As for your brakes, Messy, if you do about 4 or 5 of those 100mph stops in a row, they will begin to fade and it will be noticeable. If you're not getting brake fade, you're not stopping as hard as you think. Drilling and slotting doesn't really do much on rotors as tiny as ours. Even top end race cars experience brake fade. In town driving and the occasional hoonage on the street is typically not enough to tell the difference between decent brakes and really good brakes.



well i know im breaking hard since the front tend to lock up....i hate it...when it rains...since they lock up and the rear dont. i would have to do an autox event so i can push the car to its limits

[LiTtLe xOx BitT]

Se-i rear discs and all around drilled/slotted rotors.

[2oodoor]

No, it's not rotors warping, it's an uneven transfer layer of friction pad material.

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Alex
......which in turn will warp the rotors,.. yes?
cross drilled and slotted rotors DO work well , making your brakes last a lot longer and less rotor refinishing in the future. Just get a good set and you will be very pleased. I guarrr un teee.
One thing that really pisses rotors off :rant: is hard braking an holding the brake down at the complete stop, I always kind of roll forward a bit so that I dont hold the calipers down on the rotor on one spot so as to cool them evenly after an extremely hard stop. Nine times out of ten when I turn slash machine a rotor , the bad spot is shaped just like a pad, or in other words where the caliper/pad assy held the rotor while it was red hot.
Like 2nd Gen Guy said as well, changing your brake fluid helps, but not neccessarily changing the complete solution, just changing out with clean fresh DOT 3 or 4, should suffice. What happens is the fluid accumilates moisture, water... and that boils.. which makes your calipers not hold as well when you have stopped so hard your rotors are almost cherry red hot. (a little dutch oven effect inside your calipers then, heh heh) Hence a major cause of brake fade.
Another thing, too worth mentioning is rotor contamination from open wheel designs, these cool wheels look good and do help disipate heat from the axle but they also invite road contaminates, not to mention armor all and such. Be carefull about getting stuff on the rotor when you doll up your wheel/rims.

[2oodoor]

well i know im breaking hard since the front tend to lock up....i hate it...when it rains...since they lock up and the rear dont. i would have to do an autox event so i can push the car to its limits
that does not sound right MH, your rear brakes should be handling the greatest intial weight from the first application of brake pedal, then the fronts work on extinguishing the momemtum. I assume you swapped the prop valve from your donor car, maybe still there is a problem .. possibley in the flexable lines or master cylinder. With low profile hard tires you will have a tendency for the fronts to dominate in the skid.. I guess you are bumping the pedal when this happens to prevent lock up ? But then again you said when it rains, so your whole problem could be tires and caster.

[MessyHonda]

that does not sound right MH, your rear brakes should be handling the greatest intial weight from the first application of brake pedal, then the fronts work on extinguishing the momemtum. I assume you swapped the prop valve from your donor car, maybe still there is a problem .. possibley in the flexable lines or master cylinder. With low profile hard tires you will have a tendency for the fronts to dominate in the skid.. I guess you are bumping the pedal when this happens to prevent lock up ? But then again you said when it rains, so your whole problem could be tires and caster.


yeah i notice that the rears dont like to stop that good. im going to swap the calipers over since one is going to need a rebuild. and yes i have to do a alingment to the car since its lowered with new shocks and springs.

[2oodoor]

yeah i notice that the rears dont like to stop that good. im going to swap the calipers over since one is going to need a rebuild. and yes i have to do a alingment to the car since its lowered with new shocks and springs.
oh yeah I was going to ask you if you lowered it yet too.. if you really have a problem with the front locking after you do the obvious simple resolutions, then you may want to look at adjustable prop valves.
Another thing too, is check your rear pads, if you had any E brake issues you could have glazed them, thus reducing friction properties. REally a number of things could make the rear pads glaze...(crystalize is an old school term) it is pretty common for rear glazing to begin a series of symptoms to show up with brakes shortley afterwards.

[2oodoor]

Dp

[MessyHonda]

oh yeah I was going to ask you if you lowered it yet too.. if you really have a problem with the front locking after you do the obvious simple resolutions, then you may want to look at adjustable prop valves.
Another thing too, is check your rear pads, if you had any E brake issues you could have glazed them, thus reducing friction properties. REally a number of things could make the rear pads glaze...(crystalize is an old school term) it is pretty common for rear glazing to begin a series of symptoms to show up with brakes shortley afterwards.


yeah i switch over my prop valve when i did the swap its a 40/40 one. the regular lx-i one is like 40/35. i have no issues with my ebrake....it holds fine with just a couple clicks....like i said i think the calipers are the problem....i will upgrade them to the 1st gen legend ones as soon as i find a set.

[2oodoor]

yeah i switch over my prop valve when i did the swap its a 40/40 one. the regular lx-i one is like 40/35. i have no issues with my ebrake....it holds fine with just a couple clicks....like i said i think the calipers are the problem....i will upgrade them to the 1st gen legend ones as soon as i find a set.
E brake issues would be....they could be holding the pads against the rotor if out of adjustment or otherwise not functioning correctley. It may not be holding the rotor but if it is resting on the rotor too hard they will be polishing the pads,

[oldschool3g]

Powerslot roters with AEM brake pads work perfect. Ive had that setup for about 4 months now and love them

[mike10562004]

i work at cains tire and automotive my boss said to never turn cross drilled and slotted rotors b/c it will f up the turning machine so i would replace with stock rotors

[Kelvin]

Im actually saving up money to upgarde my brake system and am gonna buy slotted. Reason being the other day i braked from a pretty high speed and experienced some fade not to mention a weird pedal feel. I think its good insurance if you tend to drive at higher than posted speeds or if you ride your brakes alot. if not blanks, a good set of pads and good brake fluid will do you well.

Slotted rotors probably won't help brake fade much. IT sounds like your pads are crap organic compound or something that don't really work well once they're hot.

[Kelvin]

Sometimes thats the case.

No. Always the case.


But I think for most passenger cars this is wrong.


Considering he's talking about street cars and race cars.... you're wrong again. This definitely applies to passenger cars.


This guy with Stoptech runs only high end brakes,

1. He is not "WITH" stop tech. Also, he's dead now, but here's some of what he's done:

http://www.carrollsmith.com/biography/index.html

2. He is not talking about stoptech products. He is talking about BRAKING TECHNOLOGY and BRAKE SYSTEMS. What he is talking about is EXTREMELY general, and is applicable for anything from a 1960s Minicooper to today's fastest corvette.

3. Nowhere does it say what he's talking about applies ONLY to high end components. You are making things up.



Toss a set of cheap rotors onto a race car and watch what happens.

In another thread, you were agreeing with someone else who was saying that racers love cheap rotors, because they work well, and they're cheap to replace.


I believe that passenger car rotors DO warp. The runout is measurable, and it doesn't make sense that uneven brake deposits cause a nice smooth wave across a rotors surface.

The runout is UNEVEN WEAR caused by UNEVEN PAD DEPOSITS which create CEMENTITE, because the pad material changes the chemical makeup of the cast iron rotor. THIS IS NOT COMPLICATED.

You have OBVIOUSLY still not read that link, or if you have, you do not understand it.


However, some shimmy is caused by brake pad deposits, but that can be worked out easily. A few 80mph to 30mph hard threshold stops should do it.

WRONG. Again, read about cementite. You are completely ignorant of what you're talking about. A few hard stops will not alter the rotor's composition from cementite BACK to cast iron.

I'm getting really sick of you and your BS.

[Kelvin]

......which in turn will warp the rotors,.. yes?\

No. It'll cause uneven wear. Even if you 'turn' them, the uneven sections of 'cementite' will still wear unevenly, causing brake pulsation to return very quickly.

[2ndGenGuy]

I posted in here last four fucking months ago. What are you trying to prove, that you're brake fucking god now that you've read one article? I've read the fucking article, like everything I take it with skepticism. Have you ever read anything else? Have you ever even worked on brakes on car that's capable of over 110mph? Have you even been driving for more than a year? Don't fucking call me a bullshitter you inexperienced fuck. You probably don't even know what brake fade feels like.

Are you going to go through every fucking brake thread and start posting this shit?

You told a guy in another post to get new pads and rotors on his car WHEN HE HAS LOOSE UPPER BALL JOINTS. How the fuck can you diagnose bad rotors as the cause of shimmying when there are OBVIOUS loose suspension components? That tells me you're the one who doesn't know what the fuck he's talking about. Go eat a dick.

[86AccordLxi]

Hey guys, knock it off.

I agree with Kelvin (and it's Carroll SMITH, not some intarweb noob), BUT we don't need to have this argument thrown into every single braking thread.

Just make a new thread and argue about it there.

Alex

[Kelvin]

I posted in here last four fucking months ago. What are you trying to prove, that you're brake fucking god now that you've read one article? I've read the fucking article, like everything I take it with skepticism. Have you ever read anything else? Have you ever even worked on brakes on car that's capable of over 110mph? Have you even been driving for more than a year? Don't fucking call me a bullshitter you inexperienced fuck. You probably don't even know what brake fade feels like.

Are you going to go through every fucking brake thread and start posting this shit?

You told a guy in another post to get new pads and rotors on his car WHEN HE HAS LOOSE UPPER BALL JOINTS. How the fuck can you diagnose bad rotors as the cause of shimmying when there are OBVIOUS loose suspension components? That tells me you're the one who doesn't know what the fuck he's talking about. Go eat a dick.

Yes, I've read his books also. Yes, one of my cars tops out at over 150, and I've driven it up there multiple times. Yes, I do all my own brake work. I've been driving for over 10 years.

Carrol Smith > You.

[Ls1-Inside]

Cross Drilled and Slotted rotors... Pros and Cons have been constantly discussed at great length...

If you want THE FASTEST Braking! The quickest stop times, you will get them with a blank Rotor and metallic pad.

Slotting and Drilling the rotor removes some of the friction area, and gives you a measurable smaller braking surface... it will Increase your stop distances, and you won't be able to slow down as fast.

However, Drilling the rotor vents the brakes more and allows them to cool faster... Which means, if you're doing a series of consecutive hard braking you will recover from heat, or fade at a quicker rate. Although you may not be able to stop as fast at a peak, you will be able to stop quickly multiple times...

Slotting helps remove water from the rotor... it reduces friction area also... and is really only helpful if it's raining... so consider climate and weather.

Drilled and Slotted looks badass... period... Thats a big Pro! :)
http://i34.photobucket.com/albums/d136/Debug1/DIY%20Brakes/IMG_1912.jpg

If you like the look Go for it and get them. If you're doing a lot of road courses, i'd get a blank, or drilled only...

Cheap Blank rotors are great because they work decently, and when you trash them they're easy to replace w/o a huge dent in the wallet.

The biggest difference in brake fade will be from your pad and fluid choice... if you're doing a lot of hard braking and don't care about dust or low temperature squeeks get the high end pads... if you mostly deal w/ daily driving, get the quiet dustless ceramic pads and deal with the Fade... There is not "Best of Both Worlds"... you have to choose what works the best for you...

I went with drilled and slotted, with Ceramic pads because i mostly daily drive and like the look... however, when i hit "The Spiral Highway" i had some killer brake fade and the ceramic pads couldn't handle the high temps very well... fortunately the brake cooler vents, vented and drilled rotors kept them cool enough between corners to keep me from flying off the road...

GL on your choice.

-Dan

[HostileJava]

Hmmm, based on all the info here, I think I'll go with ceramic pads the next time around with my slotted/cross drilled rotors. My hawk pads throw off a lot of dust and seem to make a lot of noise. Any comments? Powerslot in the front and racingbrake in the rear.

http://hostilejava.com/temp/wheels4.JPG

http://hostilejava.com/temp/wheels5.JPG

[LX-incredible]

Nice!

[Oldblueaccord]

I couldnt stand Hawk pads I dunno if I got a bad set or what. I think there were the HPS that tirerack sold. They were expensive.They were the absolute worst pad I ever used . I made it about 3k miles and junked them for some wagners. I didnt change the rotors and the wagners still stopped better.

Axis Ultimates are starting to become my favorites over EBC greens.


wp

[Ls1-Inside]

Ceramics are a great choice for a daily driver. I've been very happy with mine. Low dust, and absolutely no squeaking! It's great!

However, the one time i was heading at a hairpin turn braking hard from 90-100 (After about 10 other hard hair pins down from 90-100) and i felt Fade almost made me throw down for racing pads the next day! I'd rather have dust and noise, then throw my Corvette off a cliff... lol

Your rotors look great btw.

-Dan

[HostileJava]

I couldnt stand Hawk pads I dunno if I got a bad set or what. I think there were the HPS that tirerack sold. They were expensive.They were the absolute worst pad I ever used . I made it about 3k miles and junked them for some wagners. I didnt change the rotors and the wagners still stopped better.
Axis Ultimates are starting to become my favorites over EBC greens.
wp


They definitely brake better then the stock pads I had on before, but they generate a lot of dust and are very noisy. Not necessarily squeaky I can just here a slight metallic sound bouncing off of walls when i get close with them. I did have one other problem with them. The shims slid forward and started rubbing on the hub of the rotor. It kinda pissed me off because by the time i caught it, it was starting to rust and that had all been painted glossy black before. Now I have to sand and paint that area when I paint the calipers. I'm waiting to do that though till I get the dual piston calipers for the front along with speed bleeders. :)

[Ls1-Inside]

They definitely brake better then the stock pads I had on before, but they generate a lot of dust and are very noisy. Not necessarily squeaky I can just here a slight metallic sound bouncing off of walls when i get close with them. I did have one other problem with them. The shims slid forward and started rubbing on the hub of the rotor. It kinda pissed me off because by the time i caught it, it was starting to rust and that had all been painted glossy black before. Now I have to sand and paint that area when I paint the calipers. I'm waiting to do that though till I get the dual piston calipers for the front along with speed bleeders. :)


Did you even do a series of hard stops and compare the braking capabilities of hawks high performance pads when heated vs. when cold? Those pads will most likely perform far better when they're at higher temperatures. Which means for cold brakes, or just poking around town - they're going to be loud and crappy... But when you need them, in the twisties, and under stress... they'll pull through. :)

-Dan

[HostileJava]

Did you even do a series of hard stops and compare the braking capabilities of hawks high performance pads when heated vs. when cold? Those pads will most likely perform far better when they're at higher temperatures. Which means for cold brakes, or just poking around town - they're going to be loud and crappy... But when you need them, in the twisties, and under stress... they'll pull through. :)
-Dan

I know they perform better under extended braking and hard braking, I just don't do a whole lot of that. I want the best of both words i guess........

[Ls1-Inside]

I know they perform better under extended braking and hard braking, I just don't do a whole lot of that. I want the best of both words i guess........


Thats exactly why i advocate Ceramics for the most part. They're pretty much cover all the bases... even a hard stop or two they're fine for... it's just the high temp stuff they loose their bite...

-Dan

[Kelvin]

Axis Ultimates are starting to become my favorites over EBC greens.
wp

It's the best performing street pad I've ever tried. The only, ONLY downside to them is they dust. A LOT. But man do they stop well. :)

[guaynabo89]

i work at cains tire and automotive my boss said to never turn cross drilled and slotted rotors b/c it will f up the turning machine so i would replace with stock rotors

That is incorect.

They can just as easily be resurfaced. The only difference is you cant ram the cutting edge into the cossedrilled/slotted rotor and have to make more light passes as compared to one hard pass on blank rotors. You try that and you will jam the machine and or brake something

[Oldblueaccord]

Did you even do a series of hard stops and compare the braking capabilities of hawks high performance pads when heated vs. when cold? Those pads will most likely perform far better when they're at higher temperatures. Which means for cold brakes, or just poking around town - they're going to be loud and crappy... But when you need them, in the twisties, and under stress... they'll pull through. :)
-Dan


I bedded them in just like the instructions and used new rotors as well. This is with the stock 10.3" set up and falken azenis (old ones ) as well 205/50/15

I got real pissed at them and dragged them down the highway about a mile and then came off and exit ramp about 80 and jammed on them as hard as a dare they still didnt stop with a shit. Didint get hot either or smoke either. I really should have sent them back I think there was something wrong with there make up.

I agree I like pads that stop. dust noise doesn't mean much to me.

wp

[Oldblueaccord]

That is incorect.
They can just as easily be resurfaced. The only difference is you cant ram the cutting edge into the cossedrilled/slotted rotor and have to make more light passes as compared to one hard pass on blank rotors. You try that and you will jam the machine and or brake something

On and off cuts might break a carbide cutter is prolly what there worried about and there expensive on a brake lathe. I had a set cut once just for kicks they seemed ok this was stock rotors I slotted my self.


wp

[mike10562004]

the pistions might not be releasing all the way or one could be releasing slower then the other causing the shaking problem i know we had a 97 civic yester day with the same problem we ended up changing the lines adn putting a new caliper on the left side and it solved the problem

[Kelvin]

That is incorect.
They can just as easily be resurfaced. The only difference is you cant ram the cutting edge into the cossedrilled/slotted rotor and have to make more light passes as compared to one hard pass on blank rotors. You try that and you will jam the machine and or brake something

I've had my slotted/dimpled rotors on my other car turned many times, whenever I switch pads. It's not a problem.

[2ndGenGuy]

I've had my slotted/dimpled rotors on my other car turned many times, whenever I switch pads. It's not a problem.

What did you get them turned for? They can't warp, and pads can't leave deposits that don't turn to cementite.

[LX-incredible]

What did you get them turned for? They can't warp, and pads can't leave deposits that don't turn to cementite.
:Owned:

[Kelvin]

What did you get them turned for? They can't warp, and pads can't leave deposits that don't turn to cementite.

What part of "whenever I switch pads" did you not understand???? It's normal brake work procedure to turn the rotors if you're putting on new pads.

PS: Stop with the double negatives. It's confusing.

[mike10562004]

I've had my slotted/dimpled rotors on my other car turned many times, whenever I switch pads. It's not a problem.


i would like to see the machine you got them turned on b/c you cant turn them on any of ours they use a dimond plated triangle tooth to cut them so there is no possible way you can have sloted rotors turned

<big> they prob. just buffed them with the dimond brush its like a sanding wheel but it has dimond plated balls on it

[Oldblueaccord]

Try high speed steel if you got one its a little more forgiven to shock then carbides are.

Mine were on what looked like and old Ammaco brake lathe at a NAPA thats closed now. He just told me he made 3 light passes.

Luckily i havent had a warped rotor in more than a year since I went to Type R brakes. It was the number one reason I did it.


wp

[2ndGenGuy]

What part of "whenever I switch pads" did you not understand???? It's normal brake work procedure to turn the rotors if you're putting on new pads.

PS: Stop with the double negatives. It's confusing.

It's not confusing.

And you still didn't answer why you have your brakes turned, part of normal brake work? What for? It costs $10 to have a rotor turned at least, and new *cheap* rotors are like $15 each. So why would you shave material off of your rotors. I GET that it's part of your normal brake work, but WHY? Why would you do something that you don't need to do?

[Ichiban]

i would like to see the machine you got them turned on b/c you cant turn them on any of ours they use a dimond plated triangle tooth to cut them so there is no possible way you can have sloted rotors turned
<big> they prob. just buffed them with the dimond brush its like a sanding wheel but it has dimond plated balls on it
It is a copper colored triangle or square? That is a carbide insert. I doubt anyone would use PCBN tooling for surfacing brakes, ever.


No. It'll cause uneven wear. Even if you 'turn' them, the uneven sections of 'cementite' will still wear unevenly, causing brake pulsation to return very quickly.
This is absolute BS. Cementite (or Iron Carbide Fe3C) forms in steel and iron as it is cooled below its lower critical temperature, which is around 725 Celsius. Above this temperature, carbon is actually solulable in iron, but when it cools, it is "kicked out" of solution with the iron, and coalesces into pockets of cementite and almost pure iron, called ferrite. Together these patches of ferrite and cementite are termed "Pearlite". These microstructures are here to stay, and in any particular proportion that they were originally present in. They can be modified by cold working, forging, or heat treating, but not changed in quantity. One cannot form more cementite in a piece of iron, no matter how hard you brake.
I'd love to scan my notes and textbooks on the subject, if anyone disagrees.
I studied metallurgy in school, being, well, a machinist, so if you want to argue about metal, you've come to the wrong place.
Oh, and who the hell is Carroll Smith?
Finally, who honestly believes that a brake rotor that is heated unevenly and cooled even more unevenly is not going to experience internal stresses leading to warping and cracking? Think about it. The outer disc of the rotor is heated rapidly, as well as subjected to a lot of force, while the center of the rotor sits on a nice cold hub. Furthermore, that smoking hot rotor starts to cool as soon as you do stop, well, except for the 1/3 of its face which is still covered by and in contact with smoking hot brake pads. Now it is cooling unevenly across its face. Tell me that won't warp a rotor.
Cementite indeed!:flip:

[Kelvin]

It's not confusing.
And you still didn't answer why you have your brakes turned, part of normal brake work? What for? It costs $10 to have a rotor turned at least, and new *cheap* rotors are like $15 each. So why would you shave material off of your rotors. I GET that it's part of your normal brake work, but WHY? Why would you do something that you don't need to do?

Uh, it wasn't on my 3G. On my 3g, I just use new rotors whenever I switch pads, they're cheap. My other cars are rare enough not to have nice cheap rotors available. :( Rotors on those cars unfortunately cost upwards of $300 a set.

[Kelvin]

This is absolute BS. Cementite (or Iron Carbide Fe3C) forms in steel and iron as it is cooled below its lower critical temperature, which is around 725 Celsius. Above this temperature, carbon is actually solulable in iron, but when it cools, it is "kicked out" of solution with the iron, and coalesces into pockets of cementite and almost pure iron, called ferrite. Together these patches of ferrite and cementite are termed "Pearlite". These microstructures are here to stay, and in any particular proportion that they were originally present in. They can be modified by cold working, forging, or heat treating, but not changed in quantity. One cannot form more cementite in a piece of iron, no matter how hard you brake.
I'd love to scan my notes and textbooks on the subject, if anyone disagrees.
I studied metallurgy in school, being, well, a machinist, so if you want to argue about metal, you've come to the wrong place.
Oh, and who the hell is Carroll Smith?
Finally, who honestly believes that a brake rotor that is heated unevenly and cooled even more unevenly is not going to experience internal stresses leading to warping and cracking? Think about it. The outer disc of the rotor is heated rapidly, as well as subjected to a lot of force, while the center of the rotor sits on a nice cold hub. Furthermore, that smoking hot rotor starts to cool as soon as you do stop, well, except for the 1/3 of its face which is still covered by and in contact with smoking hot brake pads. Now it is cooling unevenly across its face. Tell me that won't warp a rotor.
Cementite indeed!:flip:

Carroll Smith= author, racecar driver, engineer, famous in many of the world's biggest circuits.

http://www.carrollsmith.com/biography/index.html

Read it.

Then read this:

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

[Ichiban]

Did you actually read what I wrote? I can scan and post pages from my textbook supporting this. I find it hard to believe that a guy who raced cars can upset centuries of chemical and metallurgical research. I've studied the subject in school; it's essential knowledge to what I do. You read one online article.

Remember that the earth was flat once, too.

[Kelvin]

Yeah I did, and I also haven't read your vast experience in car racing, or your experience in lemans. What you say makes no sense to me, you're just saying a bunch of technobabble. Are you honestly saying that Carroll Smith is wrong? Because I doubt his book would have been published for this many years with a huge glaring flaw in it, especially when it's read by engineers/dorks/car geeks with technical backgrounds.

[HostileJava]

Did you actually read what I wrote? I can scan and post pages from my textbook supporting this. I find it hard to believe that a guy who raced cars can upset centuries of chemical and metallurgical research. I've studied the subject in school; it's essential knowledge to what I do. You read one online article.
Remember that the earth was flat once, too.


I'd actually love if you could scan the pages and cite the source. I'd give far more credibility to a science text book if that's what it is. I don't know Carroll Smith's educational background but an engineer is a far cry from a chemist. They may both have backgrounds in math and science but they're completely different fields. I really think a chemist is the type of person you'd need to talk to, to find out if what your stating is true. And of course I encourage both of you not to just blindly believe whatever you read. Text books have been known to be wrong and sometimes the teachers using them don't know the difference, and sometimes people writing books don't alway check or backup all the facts that there publishing or are simply repeating what they've been told.

[Kelvin]

Here's another pretty technical article on the formation of cementite in cast iron brake rotors:

http://www.powerbrake.co.za/pages/tech_01_judder.htm

[HostileJava]

Here's another pretty technical article on the formation of cementite in cast iron brake rotors:
http://www.powerbrake.co.za/pages/tech_01_judder.htm
Of course you realize you could post all the articles you want on the subject and it wouldn't mean a thing without the source of the information being cited. The problem is of course they could just be getting all there information from the very book your talking about. I'd like to believe that everyone who publishes anything always checks there information to be sure it's correct but without citing some sort of research or doing research of there own and publishing it, it means nothing. While what these articles are saying makes sense, without knowing the science behind it, there's no way to say if it's the case or not. I'm a computer tech and I can think of several "urban legends" which a lot of technicians and users now accept as fact because the information has been around so long everyone just believes it. Keep in mind I'm not saying your wrong or that your right. I'm just saying posting links to these articles without citing reliable research or information to back it up means nothing to me. All of you can argue about the subject all you want posting various articles and what not but it all comes down to proving your information is valid.
So stop the petty bickering and backup your claims with some proof:hmph:

I of course couldn't care either way who's right and wrong, just as long as the proper information is posted and backed up.

[Ichiban]

Here are a few scans from my textbook, Technology of Machine Tools, 6th Edition.

The first page describes the lameller arrangement of iron carbide (cementite) and pure iron (ferrite) into grain structures known as perlite. This arrangement can be seen in steel and cast iron with a microscope, it's actually fairly big. It also talks about how the carbon completely dissolves in the iron when it's heated above the decalescence point. When the metal is cooled past the decalescence point, the carbon comes back out of solution as cementite.
http://i82.photobucket.com/albums/j263/guyhatesmycar/scan0001-1.jpg
http://i82.photobucket.com/albums/j263/guyhatesmycar/scan0002.jpg
Here is god: the iron carbide diagram at the top of the page. Here you can see that steel (and cast) to the right of the hypereutectoid (more carbon than the iron can absorb below recalescence point) exists as a stable mixture of Pearlite (cementite and ferrite) and pure cementite.


http://i82.photobucket.com/albums/j263/guyhatesmycar/scan0003.jpg

Heat cycling the material will NEVER cause more cementite to form, it all already has. It's like turning up the heat in your house and expecting more furniture.

Edit: Oh and I forgot, see the second page where it states that lower heat treating temperatures are ideal to avoid WARPING of the material. Have you ever heat treated anything? Let's just say that if its under an inch thick and you don't hold it in place, it comes out looking like a pretzel, every time. And I'm pretty sure that piece of 1090 plain carbon steel that I was spheroidizing didn't have uneven brake pad deposits anywhere on it.

[Kelvin]

Eh, I still think you're wrong. Here:

http://ws.ajou.ac.kr/~powder/files/Phase(2006-2)/phase%2011-20-06.pdf

That's from a brake manufacturer, about 'white' cast iron (cementite) and how it forms into cementite. It happens through heating and cooling cycles, because the molecules 'rearrange' during these processes. Just like heating metal and then cooling it rapidly changes it's qualities, so does the massive cycles of heat of your rotor, along with the pad deposits.

[2oodoor]

roodoo2pads or rotors involving aftermarket products or how to use them CAN NOT be held to a protocol of application that can be TAUGHT as FACT. Only opinions, shared experiences, and recommendations are usable communications for these subjects.
That said, we need to remain open minded to others shared experiences (real life) and not try to preach something that was written by someone else and then tell people they don't know what they are talking about when they share non-fictional recollections of factual events to back it up.

same bat time same bat place same bat channel

This is a very interesting argument, a long standing argument in the trade. GM and other automakers say not to turn rotors, I have been to several brake clinics that also claim that rotors do not need to be machined when purchased new. Kelvin, you stress the importance of pads over that of rotating surface, using the linked references. guyhatesmycar, you hold an obvious opposition to that theory. Well.... you are both right.
Kelvin I won't flash my creds on you, I know you will drop my clip and only let me get one round off... but here it is bang (echo) bang.. having experience in a police fleet where they beat the hell out of the brakes,as well as some other commercial areas of brake work, sometimes time and money are factors aside from the fact of ulltimate machine operations. In that aspect, yes it is necessary to turn rotors, even new ones, to get the cars repaired properly and back in service, back to the customer... quickely without returns.
Guyhatesmycar, your reference material is right on the mark as well. But ultimately in the bottomless funding support of a profiting race team scenerio,, with time to experiment and work out details, and mechanics assigned to each area of the car, Kelvin and Carrol Smith's theories are pretty accurate as well. Both of these opinions can be utilized by entheusiists and owners as well, but even then time and money are factors, time IS money a lot of times. Daily driven cars, weekend warriors, hell all can benefit from both aspects of the discussion. Like all information and teaching materials, the retention of the information must be taken "with a grain of salt" for anyone to thoroughly understand and apply the knowledge to their own suit.

[2ndGenGuy]

I was told by a local brake shop that they have found that OEM rotors on a lot of brand new cars were already below spec for thickness. The owner of the shop said auto manufacturers were cheaping out of brake rotors and that they coudln't be turned. Just a tidbit I found interesting.

[Ichiban]

I could entertain the thought that some other factor in the metallurgy of cast iron is responsible for making hard spots in brake rotors, but the application of the term "cementite" in this instance is wrong. If a solution of iron and carbon is cooled to the point it solidifies, cementite will form in a given quantity proportional to the carbon content. Once a given quantity of said solution cools, all the cementite that could or ever will be there is there. I'm going to look into the possibility that other common alloying elements can be responsible for this situation.

I also stand by the statement that heat will physically distort metal. I have seen this with my own eyes many times.

[Ichiban]

Eh, I still think you're wrong. Here:

http://ws.ajou.ac.kr/~powder/files/Phase(2006-2)/phase%2011-20-06.pdf

That's from a brake manufacturer, about 'white' cast iron (cementite) and how it forms into cementite. It happens through heating and cooling cycles, because the molecules 'rearrange' during these processes. Just like heating metal and then cooling it rapidly changes it's qualities, so does the massive cycles of heat of your rotor, along with the pad deposits.


I just read the article you posted, and I couldn't agree more.

"White cast irons form eutectic cementite during solidification."

Page 50.

[mike10562004]

It is a copper colored triangle or square? That is a carbide insert. I doubt anyone would use PCBN tooling for surfacing brakes, ever.


no the triangles at my work are look like gold but they are dimond plated they last a fucking lot longer then the carbide w/e ones but he said if you break one of the dimond plated ones then you dont know what the fuck you are doing

[2oodoor]

no the triangles at my work are look like gold but they are dimond plated they last a fucking lot longer then the carbide w/e ones but he said if you break one of the dimond plated ones then you dont know what the fuck you are doing

I use diamond round bits with no problems. Since changing to slotted rotors brakes last three to five times longer than before. Where a car would come in needing brakes every 3 months, I wont see the ones with slotted rotors for at least 9 -12 months.. BIG difference

[guaynabo89]

all I want to add is that from my personal experiance you take any metal and apply heat and it will expand. cool that heated metal and it will contract. Take that metal and unevenly run it through those cycles and it will distort. Im not sure if this is just basic laws of physics or what but Im pretty sure iron is bound to those rules of distortion.

[Ichiban]

no the triangles at my work are look like gold but they are dimond plated they last a fucking lot longer then the carbide w/e ones but he said if you break one of the dimond plated ones then you dont know what the fuck you are doing

From what I understand, the diamond cutting tools have even poorer shock resistance than the carbide inserts, and comparable to brazed tip carbides. My book here recommends straight tungsten carbide for cutting of cast iron.

[Ichiban]

Eh, I still think you're wrong. Here:

http://ws.ajou.ac.kr/~powder/files/Phase(2006-2)/phase%2011-20-06.pdf

That's from a brake manufacturer, about 'white' cast iron (cementite) and how it forms into cementite. It happens through heating and cooling cycles, because the molecules 'rearrange' during these processes. Just like heating metal and then cooling it rapidly changes it's qualities, so does the massive cycles of heat of your rotor, along with the pad deposits.


Jeez Kelvin, you are a such a gentleman, posting information supporting my side of the argument. If you read it over again, ignoring the crap from the other website, you will have a good idea of what I've been talking about.

Why would TRW heat cycle and stress relieve its rotors to reduce warping while in service if brake rotors don't warp? Page 88

Some good info w/pic's on martensite and bainite, two of the iron/carbide microstructures I'd yet to mention.

[Kelvin]

all I want to add is that from my personal experiance you take any metal and apply heat and it will expand. cool that heated metal and it will contract. Take that metal and unevenly run it through those cycles and it will distort. Im not sure if this is just basic laws of physics or what but Im pretty sure iron is bound to those rules of distortion.

Sure. And it's basic common sense that rotors are DESIGNED to get hot. And then cool. And get hot again. And then cool. X 1000100010101010 times.

It's also common sense that Carroll Smith knows more about cars than Dr. Scientist over there.

[Oldblueaccord]

From what I understand, the diamond cutting tools have even poorer shock resistance than the carbide inserts, and comparable to brazed tip carbides. My book here recommends straight tungsten carbide for cutting of cast iron.

"the diamond cutting tools have even poorer shock resistance than the carbide inserts" end quote

Usually they do there harder or just as hard as carbide. Plus there very expensive in relative terms so breaking one would be cost effective of a 5$ rotor turn job so most shops turn that work down.

The harder something is the more brittle it gets just as a rule of thumb. Kinda like glass its hard but push it a little to much and its broke.

I uses HSS tooling for turning shafts with a key way in them they handle the on /off shock of skipping over the keyway. Thats another way of explaining it.

EDIT: these look like carbide inserts to me

http://www.ammcoats.com/Products_Details.aspx?id=740245215


wp

[Ichiban]

I'm saying Carroll Smith's theory is wrong. I assumed you wanted to know why. People using common sense are agreeing with me, I just have the education, understanding and material to back it up. The TRW post clearly supports what I've been saying, you should read it. Do some basic online research. Carroll Smith's lemans experience will never overthrow the iron carbide model, ever.

BTW I'm not a fucking scientist. I gained my knowledge through education, not some pain in the ass online article.

Oldblue: I'm assuming you are saying that the diamond tooling is too fragile and expensive to use on a cheapo brake rotor job? Because thats the impression that I had. I've used carbide inserts to make an interrupted cut on 316 Stainless before and had excellent results, though I knocked the cutting speed back to about 30SFM. I've never had luck using HSS on cast brake drums, the abrasiveness destroys the tool edge within seconds, even with minimal speed and a moderate feed. (and a neutral to positive rake ground on the bit) We parted out an old giant brake lathe awhile ago and I remember it having a brazed cemented carbide toolbit installed.

[guaynabo89]

Sure. And it's basic common sense that rotors are DESIGNED to get hot. And then cool. And get hot again. And then cool. X 1000100010101010 times.
It's also common sense that Carroll Smith knows more about cars than Dr. Scientist over there.

not indefinately

plus thats where quality, composite, and casting come into play. + you get what you pay for.

cast iron blocks warp too under repeated extreme heat cycles. evident when the deck needs resurfacing for it once again to be true for proper cylinder head sealing and bores are out of round. You trying to tell me the cementite from my brakes are gonna deposit on my block causing it to warp?

While Im not completely disagreeing with you This is not an absolute for every single cause of pulsating brakes. From my experiences all metals wil warp and car rotors are metal.

[Oldblueaccord]

I'm saying Carroll Smith's theory is wrong. I assumed you wanted to know why. People using common sense are agreeing with me, I just have the education, understanding and material to back it up. The TRW post clearly supports what I've been saying, you should read it. Do some basic online research. Carroll Smith's lemans experience will never overthrow the iron carbide model, ever.

BTW I'm not a fucking scientist. I gained my knowledge through education, not some pain in the ass online article.

Oldblue: I'm assuming you are saying that the diamond tooling is too fragile and expensive to use on a cheapo brake rotor job? Because thats the impression that I had. I've used carbide inserts to make an interrupted cut on 316 Stainless before and had excellent results, though I knocked the cutting speed back to about 30SFM. I've never had luck using HSS on cast brake drums, the abrasiveness destroys the tool edge within seconds, even with minimal speed and a moderate feed. (and a neutral to positive rake ground on the bit) We parted out an old giant brake lathe awhile ago and I remember it having a brazed cemented carbide toolbit installed.

I am saying yes on the diamond> I was answering the other guys response really.

Using an amaaco brake lathe , I'd assume, they run super slow least they did on the late 80's when I used one last that HSS works but not having one I coudn't tell you. I think I have a rotor here at work I might try. We wanted to see if our lathe would go slow enough to leave a good finish and how bad the run out would be

We really need to thank CAH for starting this thread in the first place. Only he could start this shit.

And just to add I have always suspected but cant prove it that most rotors are cast steel and not iron at all but I' ll throw that out in one of Kelvins threads just to spam it up someday.

wp

[2oodoor]

I use diamond round bits with no problems.

I was mistaken, the round bits i use are carbide not diamond. I get them from Kent Automotive

[Kelvin]

I'm going to have my automotive engineer friend come into this discussion. I don't believe a barely graduated chem major knows more than Carrol Smith.

[2oodoor]

:inout: :
I'm going to have my automotive engineer friend come into this discussion. I don't believe a barely graduated chem major knows more than Carrol Smith.
ok I forgot what was being debated here. Can we refresh the points in bullet format so they may be addressed individually.
metaphor: brakes faded delivering point/slid into brickwall with this argument/ grabbing e brake engineer friend:bowrofl: it's a joke , man

[Ichiban]

I'm going to have my automotive engineer friend come into this discussion. I don't believe a barely graduated chem major knows more than Carrol Smith.

Go right ahead, if he has any knowledge of metal, even at all, he will side with the iron-carbide diagram.


BTW Carrol Smith doesn't know anything, he's dead.

[Oldblueaccord]

I was mistaken, the round bits i use are carbide not diamond. I get them from Kent Automotive

well truefully the only thing i ever seen diamond was a dressing tool

http://home.comcast.net/~joeblowut2004/photos/HSS_cutter.JPG

I took a crack at an old slotted rotor I had at work before I got off shift. Cut it at the slowest speed on our lathe and it cut really well. I just spent about 10 minutes on the setup and that tool is prolly as old as I am.

Its defintely cast iron.



wp

[Ichiban]

well truefully the only thing i ever seen diamond was a dressing tool

I took a crack at an old slotted rotor I had at work before I got off shift. Cut it at the slowest speed on our lathe and it cut really well. I just spent about 10 minutes on the setup and that tool is prolly as old as I am.
Its defintely cast iron.
wp

Comes off in a grey sandlike powder instead of chips? That would be cast. What were you cutting it with? HSS or carbide?

[Oldblueaccord]

That picture is the cutting tool.


wp

[Ichiban]

I misunderstood.

So obviously HSS cut it fine for you, even with the slots.

[Kelvin]

I misunderstood.

AHAHAhaha.

Okay guys: Who do you trust? A guy famous for his racing career, experience, and has written some of the best books on setting up a race or street car in the business?

Or some self proclaimed metal expert who can't even tell a cutting tool from metal shavings?

:rofl:

[2ndGenGuy]

AHAHAhaha.
Okay guys: Who do you trust? A guy famous for his racing career, experience, and has written some of the best books on setting up a race or street car in the business?
Or some self proclaimed metal expert who can't even tell a cutting tool from metal shavings?
:rofl:

You come on the forums as a noob, whore up all of the brake threads, call everybody on here idiots, bullshitters, and dumbasses and so far haven't been able to back up anything with more than a SINGLE link. No evidence from yourself. Carroll Smith isn't that famous either. We've got people from all over saying you are wrong, people with combined experience which probably totals up more than Carroll Smith's.

And by the way he wasn't referring to the picture. You're so illiterate, you take things we say out of context, and you don't answer the majority of the questions we ask you. Also, you are really good at avoiding any points that completely prove you wrong. You've completely insulted the community from which you're in here to get information from.

I think most of the problem here is your shitty attitude. Instead of provoking mature commentary and discussion, you just come in and start telling everybody they are wrong and to read some lame article, then toss insults at them. That's right, that article is LAME. Even good writers, and experienced people are wrong. Just because Carroll Smith hasn't seen a warped rotor, doesn't mean it doesn't happen.

Have you ever seen someone get struck by lightning? No, I didn't think so. Does that mean it doesn't happen? Of course not. You may perhaps be older than me, but you really need to grow up. Quit being this internet badass who thinks he's so much smarter and better than everybody else who contradicts him. Open up your mind to something more than one goddamn article. Please for the love of god. Or just quit posting. That would be excellent.

[Ichiban]

Uh, to be honest at first I didn't even look at the picture until after I posted. So why don't you tell me how each different metal cuts, which angles you would grind on the lathe bit, what speeds and feeds to use. To start, what angles are ground on that lathe bit? Why are they like that? Here's a fucking clue: The way the Cementite, Ferrite and Graphite forms in cast iron as it solidifies. That is why every lathe bit is ground as it is, but you wouldn't know that because Carrol Smith never told you that. You wouldn't be able to tell the difference between Martensite and it's tempered form Bainite after heat treating. You wouldn't be able to tell why a shaft cuts differently than that material normally would because you don't have a clue about how the grain size varies due to work hardening and heating/quenching.

Oh wait, everything I know about metal grain structure is wrong because Carrol Smith said something out to lunch in a field he doesn't even routinely deal in. Guess I'm a fucking idiot. I guess hard braking causes Cementite to magically appear in iron. I guess I wasted thousands of dollars on fucking school. I would assume trowelling concrete causes gravel to form inside, right? Someone on the net told you so, it must be right, yeah?

Fuck off.

I've studied to great depth the causes and effects of what's inside iron and steel, and how varying and modifying them changes things. You come along proclaiming that left is up and the sky is goddamn purple and expect me to believe it? That cementite theory of yours is GODDAMN BULLSHIT. Maybe you understand caps better. Braking DOESN'T CAUSE CEMENTITE TO FORM.

I thought that the textbooks and links and other shit would clue you in, but you obviously can't swallow your pride and do a little online research. I looked around even at wikipedia and a few other quick google results, and there are a pile of pretty reasonable descriptions kicking around....including the TRW link you posted. Which you didn't even read yourself, which is clear. Or you would realize that you are stupid.

You obviously have never welded. Some of the dumbest people in the world have more knowledge than you in terms of metal warping due to overheating. They will all assure you that metric tons of metal are warped due to heat every day. But you won't understand this because Carrol Smith told you it won't happen.

You obviously have no respect for people on this forum. You continue to preach bullshit, even when other people question it as well.

Since I can't ask you to do the research on your own and figure out what actually happens in this situation(even with common experience and common sense guiding the way) then all I can hope is that you go away.

[2oodoor]

wow, I must say after all is said and done here, even with two decades of automotive and metal fabricating under my belt < I still learned something from the information presented.
Other than the condesending tones of the noob, It is one of my fav threads.
I must admit though had it not been for the conflicting concepts, the brunt of the most usefull information likely would never have been presented.:naughty: :wave:

[Kelvin]

Carroll Smith isn't that famous either.
Yeah, actually he is. "Engineer to win" and "Tune to win" and "Drive to win" are huge successes in the book industry. The reason you don't think he's famous is because you're ignorant.
Also, I DID bring personal experience to the table, like I've explained many times, I've had ZERO pedal pulsations after reading his ideas, adopting them, and switching to pads with super high max operating temperatures.

We've got people from all over saying you are wrong, people with combined experience which probably totals up more than Carroll Smith's.
What a joke. OF COURSE THEY ARE. That's because this is an old wive's tale. I suppose 'swimming after eating will cause cramps is BS' is something that "MOST PEOPLE" would disagree with me on too, but it is false.

I think most of the problem here is your shitty attitude.
Or that you're ignorant. If you weren't so ignorant, we wouldn't have a problem. Now run along, and keep telling yourself Carroll Smith isn't famous, and that all his books are BS, even though automotive engineers cherish them as biblical.


I guess hard braking causes Cementite to magically appear in iron.
Um... yeah, actually it does. Read the link I posted. Cementite is formed under really high heat. ..... and..... wait for it.... when you have uneven pad deposits, a lot of the time the high spots will 'glance' off the pad on every rotation, even if you aren't braking. This constant friction, this constant rubbing on every revolution causes heat, and without any time period to cool off, the rotor can reach EXTREMELY high temperatures. And what happens at such high temperatures?
YOU CAN MAKE CEMENTITE! YAY!
http://ws.ajou.ac.kr/~powder/files/Phase(2006-2)/phase%2011-20-06.pdf
Read that again. Now read the 'differen phases' that cast iron goes through, after being exposed to different temperatures. There is the ferrite iron phase, the austenite iron phase, the delta iron phase, the graphite carbon phase, and finally the IRON CARBIDE (CEMENTITE) phase.
Here's a graph so I appear as scientific as Bill Nye up there:
http://i26.photobucket.com/albums/c143/badquote/Picture9.png
Notice how it talks about cementite 'breaking down' with enough time and temperature. WHAT?! METAL'S COMPOSITION CHANGES!?!?! OMG!
http://i26.photobucket.com/albums/c143/badquote/Picture10.png
Here is a chart of 'transformations' that occur in cast iron. I understand some cementite exists in ALL rotors, but it is more or less 'evenly distributed' throughout the rotor. What happens under high temperatures is that the molecules IN the rotor, just like any other thing heated up, start to break bonds with each other, and 'rearrange' themselves. The problem is uneven pad deposits, if scuffing a pad on every revolution, can quickly get to insane temperatures in LOCALIZED REGIONS OF THE ROTOR, causing cementite 'clumps' to form, which will NOT WEAR THE SAME AS THE REST OF THE ROTOR.
http://i26.photobucket.com/albums/c143/badquote/Picture11.png
This is the SAME cast iron after being treated with different temperatures. NOTICE THAT IT IS DIFFERENT. Now imagine only heating up ONE part of your rotor, the part with a really 'high' pad deposit', which is hitting your pads on every revolution. This will cause the metal's molecular structure to change in just that localized region, resulting in a rotor that will NEVER wear evenly.
http://i26.photobucket.com/albums/c143/badquote/Picture12.png
This one is also important. It states that silicon is required for the creation of cementite. Now, if your pads have ANY 'silicon' in them, which they most certainly do, this means that at really high temperatures, with a layer of 'pad material' on the rotor, that CEMENTITE CAN FORM. Bill Nye disagrees with me, but the proof is right here in front of your eyes.
Finally, the different phases and kinds of cast iron all have different wear resisitence:
http://i26.photobucket.com/albums/c143/badquote/Picture13.png
I rest my case.

[HostileJava]

Yeah, actually he is. "Engineer to win" and "Tune to win" and "Drive to win" are huge successes in the book industry. The reason you don't think he's famous is because you're ignorant.

Stay with the subject at hand, if you continue to attack members personally you WILL find yourself with a temp ban. Also learn to use the edit button, there is no reason to post twice in a row.

[HostileJava]

The only reason I attacked him is because he was attacking me. I'll report his posts now.



Personal attacks.

That warning was for everyone in the thread really. Please don't' waste your or my time reading through the whole thread and reporting posts just to prove a point. The reason I quoted you is because you are the instigator. You can prove a point without acting like an ass. The discussion can get as heated as you want, but don't be petty and start attacking each other, it really has nothing to do with what you are discussing.


:inout: :
ok I forgot what was being debated here. Can we refresh the points in bullet format so they may be addressed individually.
metaphor: brakes faded delivering point/slid into brickwall with this argument/ grabbing e brake engineer friend:bowrofl: it's a joke , man

Yes let's get back to talking about the pretty pictures of my brakes :)

[Kelvin]

So does this threat of 'temp banning' apply to 2ndGenGuy and GuyWhoHatesMyCar also? Because I'm sick of being attacked.

[MessyHonda]

seee you made baby 3geezus mad now....:nervous:

[HostileJava]

So does this threat of 'temp banning' apply to 2ndGenGuy and GuyWhoHatesMyCar also? Because I'm sick of being attacked.

Yes it does, now stop whoring up the thread making sure that everyone will be punished equally. If you have questions about the discipline system read the TOS or PM a mod/admin.

[2ndGenGuy]

Actually, the problem isn't that I'm ignorant. The way you called guyhatesmycar a "hack" essentially is pretty fucking rude. And to go quote what I wrote, and say "I'm tired of your BS" is called "ATTITUDE". Maybe you need to look it up in a dictionary. And then to say sarcastically to LS1-Inside "oh look another genius" is also pretty fucking rude.

I don't give a rats ass if cast iron CAN turn into cementite, the fact that you say that it ALWAYS DOES is not proven by anything. You keep saying that all brake shudder is caused by cementite, and I still disagree. Proving that cementite can happen (though I'm not convinced 100% you've proven that it happens in brake applications), doesn't mean it ALWAYS HAPPENS. It also doesn't prove that rotors can't warp.

Your last post (being the best one you've posted so far and being how you should have posted a LONG TIME AGO instead of insulting people) only shows that iron, when combined with silicon forms cementite at EXTREMELY HIGH temperatures. Most braking applications don't see those kind of high temperatures. Most people never even experience brake fade in their cars. For temps to get that high, long, hard, repeated braking is required. Likely never seen on the street. And besides that, how do high-temp brake pads PREVENT this "cementite" condition?

Well sir, they can't. The fact that they're resistant to high temperatures only means that they won't transfer heat to the brake fluid which causes the fluid to boil which causes brake fade! THE PAD IS STILL MAKING CONTACT AT THOSE TEMPERATURES. Which means that high-temp pads, according to you, will still make cementite. Since there is pad material unevenly making contact with the rotors your rotors should be shuddering. This is what makes all of your arguments completely un-credible.

Explain to me how your high-temp pads have prevented your brake rotors from forming cementite.

Also, you still haven't answered my question, why do you get your rotors turned as part of a normal brake job. It doesn't make any sense and completely contradicts everything you're talking about. Again, why do you get your brake rotors turned? Why do you get your brake rotors turned?

[Kelvin]

Your last post (being the best one you've posted so far and being how you should have posted a LONG TIME AGO instead of insulting people) only shows that iron, when combined with silicon forms cementite at EXTREMELY HIGH temperatures. Most braking applications don't see those kind of high temperatures. Most people never even experience brake fade in their cars. For temps to get that high, long, hard, repeated braking is required. Likely never seen on the street. And besides that, how do high-temp brake pads PREVENT this "cementite" condition?

You didn't read what I wrote, or what Carroll Smith wrote. It isn't BRAKING that causes it, it's UNEVEN PAD DEPOSITS. I'll talk you through it, one more time.

1. You install crappy pads with a low max operating temp.
2. You properly bed the pads, putting a smooth even layer of pad material on the rotor.
3. You are driving 'spiritedly' and get your brakes pretty hot, and come to a stop, or just slow down enough to transfer even more pad material 'unevenly'.
4. This 'uneven pad deposit' is thicker than the rest of the pad material on the rotor. Now, if this 'deposit' hits your pads on every revolution, it does NOT REQUIRE BRAKING TO CREATE HEAT. Driving on the freeway will lightly hit that 'thick' pad deposit on your existing pad with every revolution, creating MASSIVE amounts of heat in very localized regions of the rotor, right on the surface of the rotor, right under the pad material. It is this area that will create cementite.


Which means that high-temp pads, according to you, will still make cementite. Explain to me how your high-temp pads have prevented your brake rotors from forming cementite.

They will prevent it by preventing UNEVEN PAD DEPOSITS FROM OCCURING IN THE FIRST PLACE. If you can avoid uneven pad deposits, you can avoid the thick pad deposits hitting your brake pads with every revolution, which will avoid 'uneven' formation of cementite. If you had cementite form 'evenly' accross the rotor it wouldn't really be much of a problem.


Also, you still haven't answered my question, why do you get your rotors turned as part of a normal brake job. It doesn't make any sense and completely contradicts everything you're talking about. Again, why do you get your brake rotors turned? Why do you get your brake rotors turned?

Because I was switching pads. I was putting in new pads. I've said this already, many times, when you asked me before. Part of putting in new pads means having a COMPLETELY even smooth rotor to contact these 'fresh' pads, so they can deposit THEIR pad material evenly across the surface of the rotor. If you don't turn your rotors, and expose fresh material, you're trying to use the existing deposited pad material from the OLD pad with the new pad, which could be incompatible. Also, the grooves in the surface of the rotor PREVENT an EVEN LAYER OF PAD DEPOSITS from occuring.

How do you not understand this?

I can only hope that you don't continue to ask me the same questions again and again and again. I've explained both situations already, and Carroll Smith explained it better than I could in his article.

[86AccordLxi]

Spot on. That's my understanding, as well (not that I'm certified or have a degree or something else).

Alex

edit: ultimately, though, the end result is mostly the same-- a rotor that is probably beyond turning.

Edit2: I've also heard from people that work at some parts store, though, that some of the new rotors they get are 'pre warped.' You put them on a flat surface and there's obvious hi/low spots. Like I mentioned, my autozone blanks are still going strong even after getting some real solid head into them.

[Kelvin]

Thank you. It's nice to know there are some people who are actually comprehending what I'm saying.

[2ndGenGuy]

You didn't read what I wrote, or what Carroll Smith wrote. It isn't BRAKING that causes it, it's UNEVEN PAD DEPOSITS. I'll talk you through it, one more time.
1. You install crappy pads with a low max operating temp.
2. You properly bed the pads, putting a smooth even layer of pad material on the rotor.
3. You are driving 'spiritedly' and get your brakes pretty hot, and come to a stop, or just slow down enough to transfer even more pad material 'unevenly'.
4. This 'uneven pad deposit' is thicker than the rest of the pad material on the rotor. Now, if this 'deposit' hits your pads on every revolution, it does NOT REQUIRE BRAKING TO CREATE HEAT. Driving on the freeway will lightly hit that 'thick' pad deposit on your existing pad with every revolution, creating MASSIVE amounts of heat in very localized regions of the rotor, right on the surface of the rotor, right under the pad material. It is this area that will create cementite.

Let me rephrase what you said, and see if this makes sense to you:

1. You install expensive pads with a high max operating temp.
2. You properly bed the pads, putting a smooth even layer of pad material on the rotor.
3. You are driving 'spiritedly' and get your brakes pretty hot, and come to a stop, or just slow down enough to transfer even more pad material 'unevenly'.
4. This 'uneven pad deposit' is thicker than the rest of the pad material on the rotor. Now, if this 'deposit' hits your pads on every revolution, it does NOT REQUIRE BRAKING TO CREATE HEAT. Driving on the freeway will lightly hit that 'thick' pad deposit on your existing pad with every revolution, creating MASSIVE amounts of heat in very localized regions of the rotor, right on the surface of the rotor, right under the pad material. It is this area that will create cementite.

Okay after reading that, what about a high-temp pad prevents it from leaving deposits? This is what I'm trying to ask you, and this is why it doesn't make any sense to me at all.


They will prevent it by preventing UNEVEN PAD DEPOSITS FROM OCCURING IN THE FIRST PLACE. If you can avoid uneven pad deposits, you can avoid the thick pad deposits hitting your brake pads with every revolution, which will avoid 'uneven' formation of cementite. If you had cementite form 'evenly' accross the rotor it wouldn't really be much of a problem.

Again, how do high-temp pads prevent uneven deposits? You're not making the logical connection. All you're saying is HIGH TEMP PADS PREVENT UNEVEN DEPOSITS. I disagree.


Because I was switching pads. I was putting in new pads. I've said this already, many times, when you asked me before. Part of putting in new pads means having a COMPLETELY even smooth rotor to contact these 'fresh' pads, so they can deposit THEIR pad material evenly across the surface of the rotor. If you don't turn your rotors, and expose fresh material, you're trying to use the existing deposited pad material from the OLD pad with the new pad, which could be incompatible. Also, the grooves in the surface of the rotor PREVENT an EVEN LAYER OF PAD DEPOSITS from occuring.
How do you not understand this?

How do I not understand this? Because this is the first time you've explained it without just saying "because I was switching pads" which is not a reason for turning rotors alone. And now you're saying that you have grooves in your rotor, which are radial around the rotor. How would this prevent an even layer of pad deposits laterally? If the grooves are evenly distributed laterally, and not wavy, I don't really see a problem. And if your case is correct, how do you know the grooves aren't already from uneven pad distribution????

The reason you have grooves, is because you're using some crazy semi-metallic pads and cheap rotors. This problem wouldn't be so bad if you used good rotors. Your chart shows the differences in the ways that metals are tempered, and shows that better iron compositions can improve wear resistance. Hence good rotors have higher wear resistance!

Thats why I kept arguing to use better rotors. You can either use cheap rotors and replace / resurface them often, or use good rotors and not replace / resurface them so often. But you began insulting me, saying I was spreading BS and to read the article. What is more practical for most people? Metallic pads and cheap rotors, or ceramic / organic pads and good rotors?

Now what's good for a person who is racing? Maybe cheap rotors and high-temp pads. Why? High temp pads prevent FADE and glazing. FADE is the major killer in your stopping ability. The temperatures on the rotors and pads are still the same if you had cheap components. Your brake fluid turns to shit, and can no longer apply the proper pressures to your pads to grab the rotors. The reason you can get away with cheap rotors is because the amount of brake wear is INSANE when you are racing, and just about ANY rotor will be destroyed at the end of a race unless you have some EXTREMELY expensive rotors. I'm talking 14 inch, 2-piece rotors with cooling holes CAST into the rotor.

To answer that question properly, go back to my argument that high-temp pads don't prevent uneven pad deposits. Now assuming this, which one would you logically have to suggest for people who don't race or the majority of the people in this forum with OEM-style brakes? The longer lasting solution, or the one that eats up rotors?

You keep insisting that EVERYTHING is cementite buildup. You keep saying that uneven pad material (which I agree can happen) can NEVER be burned off, and it always causes cementite. You keep saying that rotors CAN'T warp. I have NOT argued that cementite can't happen. I don't know for sure that it does, but you're 100% wrong that it is always the case. If it does indeed happen, I find it to be the least likely cause of brake shudder. Whether the brakes are warped, OR it's this supposed cementite, the symptoms are the same, and the rotors are toast and need to be replaced.

Go to Corvette forum, and talk to people who track day their cars. They get shudder, and FIX it by burning off and rebedding and heat cycling the rotors. It happens ALL THE TIME! People do it, and it works! If the rotors aren't toast, and trying a FREE, EASY solution helps BEFORE replacing the rotors, why not try it? Why pick apart my arguments in old threads and call me a bullshitter?


Thank you. It's nice to know there are some people who are actually comprehending what I'm saying.

Again, more of your arrogant attitude. Stick with facts.

[Kelvin]

You are completely hopeless. You can't even read correctly. That is the problem here. I CLEARLY stated in the first example that crappy pads with a LOW max operating temp are more likely to cause uneven pad deposits, because they require a much lower temperature to transfer pad material. Instead of reading this correctly, you read the opposite. You read 'expensive' instead of crappy. How? Who knows. All I know is that I'm done with you.

I give up on you. The brake lord has banished you from the land of the intelligent. He could respond to your other posts, but you've made it quite clear you're unable to understand simple paragraphs and examples correctly. I'm not sure if it's your brain, or your reading ability, but something 'just ain't right' in your comprehension abilities.

PS: I've had extremely aggressive pads on my car for 40,000 miles. Have not needed to replace a rotor or the pads yet. Have not had any pedal pulsation. At all. Always smooth. Always works great.

[Oldblueaccord]

I misunderstood.
So obviously HSS cut it fine for you, even with the slots.

yes


althought i use carbide on everything.



Hope this makes it to page 5.


wp

[Ichiban]

Nice. Really nice.

You are so fucked up in your comprehension of the material you are posting, you are making it say whatever you want it to.

I would explain how tempering martensite and bainite will eventually change the grain structure back to cementite and ferrite, thus softening the material, but you just can't wrap your head around it. That's right, heating metal composed of martensite or bainite structures will SOFTEN it. Tempering. You won't get it.



YOU CAN MAKE CEMENTITE! YAY!

Wait a second, you were right. Tempering Martensite will cause Pearlite (cementite and ferrite) to form. Even your graph says so. Unfortunately Martensite is the hardened phase of iron or steel, and your brake rotors would never be made this way. Why? Because every time you use them, they would temper themselves back to a Cementite/ferrite structure.

That's right, heat will make them become softer. Even after they cool. That is what tempering is. But you'll argue this, I only learned it in school and practiced it, but you read an article.

Your own chart states that martensite begins to temper back at 150 C, no brake manufacturer would make rotors that change phase at that temperature.

I just thought of something: Maybe brake rotors have been mildly heat treated, and Cementite is still to blame. Localized heat causes tempering of the iron back to the cementite/ferrite mix from the possible previous martensite bainite structure and makes a soft spot. That would be more plausible, given my knowledge on the subject. Oh, and the tempering chart you posted, even it agrees with me. But even this doesn't make sense because after 1 or 2 hard brake applications the heat treating would be tempered out anyways.

Basically (and everything you've posted supports this with exception of Carrol Smith)

Iron + Carbon= Cementite and ferrite, add heat, it becomes austenite (everything is dissolved) cool slowly, goes back to cementite and ferrite
Quench quickly, cementite is trapped in iron matrix, forms martensite, slowly heat martensite, tempers back to cementite and ferrite.

This is all material I was tested on in school. It is FACT.

If you mix molten Iron and Carbon and let it cool, you will get Cementite and Ferrite.

Silicon is added to PROMOTE formation of graphite, and AVOID the formation of cementite. Read it properly.

Also, saying that silicon containing brake pads will cause cementite to form is plain wrong. You are making this up. Cementite=Fe3C. There is no silicon involved. Look up the term "undercooling" and it will all make sense.

I've long studied the change in a metal's properties with heat. It's called tempering, and it's tendency is to make metal softer, not harder.

Since your theory still goes ass backwards to years of study and school, you're still wrong. Once you have the education to properly interpret what you are using for examples you will understand this.

[2ndGenGuy]

I CLEARLY stated in the first example that crappy pads with a LOW max operating temp are more likely to cause uneven pad deposits, because they require a much lower temperature to transfer pad material. Instead of reading this correctly, you read the opposite.

Editing out your condescending, insulting remarks, I will reply to this. High temperature pads prevent heat transfer to the brake fluid and other components and prevent glazing. There is nothing about high temp pads that claim to cause less material transfer. Where you came up with this, might make sense since they have a higher operating temperature, but I've sure as hell never heard this claim or heard it as reason people use high-temp pads. People get material transfer from high-temp pads all the time. High operating temp does NOT mean material transfer doesn't happen at lower temps.

Not only this, but the temps required for cementite to form, according to you, are WELL WITHIN the range of high temp pads. If it can form with cheap pads, which cause braking issues at lower temperatures, and generally will cause no further heat, then it sure as shit can form with high-temp pads as well.

I reformed that statement with the word "expensive" instead of "cheap" to show you how the effects are EXACTLY the same, and how that example of the process you keep using has NO LOGICAL BEARING on whether you use cheap materials or expensive materials.

Quit being insulting and saying how nobody understands you. We read what you're saying, and again, you avoided EVERY SINGLE POINT I made in my post. If you can't argue without being condescending, quit arguing. Quit making this into a personal thing to try and make yourself look good.


And one more point out of the realm of what I know:


Alloying additions such as Si or Al are made to suppress cementite precipitation...
www.scielo.br/scielo.php?pid=S1516-14392005000400010&script=sci_arttext


The silicon retards the growth of cementite...
www.springerlink.com/index/L083011067N6J038.pdf


Silicon promotes ferrite formation and retards the formation of cementite.
www.steeluniversity.org/content/html/eng/default.asp?catid=156&pageid=2081271601


...silicon (retarding the cementite formation and thus. increasing the stability of austenite...
http://72.14.253.104/search?q=cache:LzqLWiCMIz4J:www.us.cbmm.com.br/english/sources/techlib/report/novos/pdfs/the_role2.pdf&hl=en&ct=clnk&cd=13&gl=us&client=firefox-a


Silicon is known to inhibit cementite formation in steels
http://etd.library.pitt.edu/ETD/available/etd-04032005-165518/unrestricted/Jose_E_Garcia-Gonzalez_04-2005_PhD_Thesis.pdf

I don't think I have to say anything more.

[Oldblueaccord]

I just read a little about what was written on Carrol's site as well as stop tech. I think the point not mentioned is what was written in his book was copywirtten in 1975. What was known then about casting/ metals /race cars cams motors is old news. Its 2007 almost every thing has changed as far as cars has changed. Good read over all but I consider it ancient history.

Stop tech does not sell cheap rotor.


http://www.stoptech.com/products/rotors.shtml


Mark Donohue "Unfair advantage" is one of my favorite books from that era. Read it. Its a boiagraphy but it filled with technical aspecs of all the cars he drove. In fact the chapters are broken down buy what car he drove.

http://en.wikipedia.org/wiki/Mark_Donohue

You will be amazed at what they did not understand about aerodynamincs and how they work even in the early 70's even after they had sent a man to the moon.

wp

[MessyHonda]

:bow:......screw brakes....im stoping with magnatic fields now....lol

[2oodoor]

:stupid:

[HostileJava]

:bow:......screw brakes....im stoping with magnatic fields now....lol

Yeah but how are you stopping?

[guaynabo89]

ok how about this.............


At what temperature does cenemtite form? (im not reading al the links)

Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.

[2ndGenGuy]

ok how about this.............
At what temperature does cenemtite form? (im not reading al the links)
Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.


When the temperature of an alloy reaches 1333 ºF (733ºC), austenite transforms to pearlite (fine ferrite-cementite structure...
Source: http://www.substech.com/dokuwiki/doku.php?id=iron-carbon_phase_diagram


Temperatures between the pad and disc do not normally exceed 700°F even in heavy street use. In race use 900-1200°F is common on smaller cars and in Championship Cup race temps. shoot up to around 1500°F where discs will glow red or orange.
ALWAYS CHOOSE A PAD ADEQUATE FOR YOUR NEEDS. NEVER just choose a race compound because you think you’re a hot shot. Many/most race pads need “warm up” and don’t become effective till 350°F.
Source: http://www.ebcbrakes.com/QandA.html

And if it were true that your pads heated up from just driving, and no brake pedal pressure, to temperatures like that, then your pads would be constantly glazed and completely ineffective. They would smell, and smoke and be just plain awful.

Here's some news: yours pads are ALWAYS in contact with your rotors ever so slightly. There's just not enough pressure to heat them up to where they get that hot. If it were true that areas that contact the pad got that hot, they'd ALWAYS be smelling and glazing and they wouldn't work at all. Your brake fluid would be boiling... ugh none of that stuff makes sense at a basic or scientific level.

I'm sure most of us have driven cars that have REALLY BAD pulsation in the brakes. Do they heat up that hot when you're moving down the freeway? No, the raised areas on the rotors DON'T GET THAT HOT. Again, if they did, they would be smelling, smoking, etc.

[Ls1-Inside]

You are completely hopeless. You can't even read correctly. That is the problem here. I CLEARLY stated in the first example that crappy pads with a LOW max operating temp are more likely to cause uneven pad deposits, because they require a much lower temperature to transfer pad material. Instead of reading this correctly, you read the opposite. You read 'expensive' instead of crappy. How? Who knows. All I know is that I'm done with you.
I give up on you. The brake lord has banished you from the land of the intelligent. He could respond to your other posts, but you've made it quite clear you're unable to understand simple paragraphs and examples correctly. I'm not sure if it's your brain, or your reading ability, but something 'just ain't right' in your comprehension abilities.
PS: I've had extremely aggressive pads on my car for 40,000 miles. Have not needed to replace a rotor or the pads yet. Have not had any pedal pulsation. At all. Always smooth. Always works great.

Wow if you're going to be a completely immature, rude, noob and not address 2ndGenGuy atleast address me.
Please - to make things more clear, if you will, list your points and the facts that you're trying to get across, bulletined so you can clearly defend them, and speak to each point.

As I see it you're saying:

1) Rotors Never EVER WARP

2) Silicon actually HELPS cementite form

3) Brake Shudder is ALWAYS from Unevenly deposited material

4) Unevenly deposited pad material can NEVER be repositioned during bed-in, and your rotors will quickly turn to cementite and shudder...

5) Your Rotors/Pads exceed temperatures required to form cementite during normal daily driving (1000F+ :eek:)

6) High Operating Temperature pads will not deposit Pad Material to the rotors. And are adequate for daily driving... :rolleyes:

7) Carol Smith is super duper famous, and is an expert in the metallurgy and brake rotor technology field who can not be refuted by modern science.

8) High Temp Pads will somehow PREVENT unevenly deposited pad material

I'm sure you're making other points here... and they all look very valid... :rolleyes: Feel free to include these as well as all of your other pearls of wisdom in your list...

Or you could always choose to disregard all the points any poster makes, repeatedly link a 30+ year old opinion paper w/ no scientific studies behind it, and, oh my personal favorite, - bannish posters from "the land of the intelligent" in a child like defense.

:cheers:
Dan

[guaynabo89]

thats the point im trying to make.

I dont beleive daily driving will heat brakes enough to cause cermentite to form, some cases maybe, racing or heavy use probably. iron can warp just like any other metal. Saying it wont is like saying water wont urn to ice if I freeze it.

[2ndGenGuy]

Carol Smith is super duper famous, and is an expert in the metallurgy and brake rotor technology field who can not be refuted by modern science.

:rofl: :rofl: :rofl: :rofl:

[Ichiban]

This is all getting rather hilarious, I'm glad it's not just me on this side of the discussion. I thought I'd rehash a few basic heat treating principles for clarity: The pictures and graphs both Kelvin and myself have posted give a visual representation of what I'm about to say.

Iron and Carbon in solid solution: Above 930 C Carbon dissolves completely in Iron. This mixture is homogenous, and consistent throughout. It is non-magnetic and slightly denser than the equal mass of solidified mixture. This material is termed Austenite and is capable of plastic deformation. Forging is carried out at this temperature range.

Pearlite Formation: If Austenite is allowed to cool naturally, several things can happen depending on carbon content. If the content is below 0.83 percent, Pearlite will form interspersed with grains of ferrite, pure iron. This steel is typically non hardenable. One can quench it from austenite and achieve little or no hardness gain. If the Austenite contains more than .83 percent carbon, it will cool to form Pearlite grains interspersed with Cementite (iron carbide) which forms outside the pearlite grains due to it having nowhere else to go. If the Austenite solution contains more than 1.7 percent carbon, then Pearlite, Cementite and grains of Graphite are now formed. Why? The capacity of the solid Iron to absorb carbon at 1.7 percent is exceeded, and the excess carbon forms grains of graphite, which is pure carbon. Solid material with more than 1.7 percent carbon is considered cast iron.
Pearlite is soft, ductile, tough and easily machinable grain structure.

Martensite: If austenite with a high carbon content is quenched in water or oil, the rapidly forming Cementite and Ferrite grains don't have time to seperate out fully. Instead a needle like structure of martensite forms. It is very fine grained, and is characterized by exceptional hardness and brittleness. High carbon steels are hardened by this method (drill bits, chisels, etc.) The Cementite and ferrite are still there, they are just dispersed in very fine grains instead of the pearlite formation due to the rapid cooling.

For the purpose of this discussion I will avoid the topic of air hardening alloys, which do not require quenching to harden, only normal cooling. As these steels are alloys and we are dealing with generally plain carbon items, it really isn't important.

Tempering and Drawing: As Martensite is usually way to hard and brittle to be of much use, one must take some of the hardness and brittleness away and induce some other desireable traits, like toughness and some ductility. You can do this by reheating the martensite item slowly to a specified temperature, usually a tempering oxidation color chart. You know how steel turns tan, then brown, blue and black as you heat it? Well, we actually use those oxidation colors to tell what degree we have heated the item to during tempering. Too cold, and the material will fracture under use. Too hot, and the hardness will be lost, and the item will wear rapidly, as the martensite has been changed back to cementite and ferrite (pearlite) which is the softer phase, remember?

Suppose you wish to machine an item of hardened material? You can use a process called a spheroidizing anneal to put all the martensite back to pearlite. Sound complicated? Not really, you heat the material back up to pure austenite, then cool it slowly over a period of hours to reform the pearlite grains, (ferrite and cementite) which machine easily due to their large round shape, hence the spheroidizing anneal.

Case hardening: If a mild steel item needs to have the abrasion resistance of a hard alloy, or needs to retain a ductile tough inner core, you can case harden it. Basically, the part is soaked in a carbon rich solution for a period of time, and the outer surfaces absorb the carbon and become hardenable. Case hardening usually affects only .010 to .050 below the surface of the part.

Summary: While it's true that the presence of cementite determines the hardenability of iron or steel, its infact the particular grain structure of the material that affects hardness. Due to its high carbon content, cast iron is typically hard and brittle, making it ideal for wear surfaces but not for structural parts. Cementite will form in two ways: Slow cooling from austenite, or tempering Martensite.

Either way, the presence of cementite indicates a softer, ductile grain structure and not the harder wear resistant "patch" used to explain uneven rotor wear. The slow heating/cooling cycles of a brake rotor will tend to anneal the material, rather than harden it.


References:

1. Machinery's Handbook, 27th edition.

2. Trac Trades/Common core Line F Metallurgy and heat treating.

3. ITAC Machinist/Millwright Line ? Heat treat steel

4. Technology of Machine Tools, 6th Edition.


I will add/sort more references tonight.

[Kelvin]

More articles from BRAKE ROTOR COMPANIES that claim rotors never warp:
http://www.raceshopper.com/tech.shtml#warped_rotors
"Warped rotors (in most instances) are caused by the brake pads being operated at temperatures outside of their specified range. When the pads get too hot the pad material actually melts and 'fuses' itself to the rotor surface and creates a 'bump' on the surface of the rotor. In most cases this is not noticeable to the naked eye. This creates an annoying vibration when the brakes are applied"
This is exactly what I said above. Shitty pads with a low maximum temperature= uneven pad deposits. Yet still, certain people argue and claim that high temperature pads will work exactly the same as shitty organic pads. Why? Who knows. Some people buy tornado fuel savers.
Here's another BRAKE MANUFACTURER that claims that rotors never warp, and I'm guessing they know more about rotors than certain so called 'experts' on this forum.
http://www.performanceoiltechnology.com/brakingsystems.htm
"The problem with this diagnosis and repair procedure is that first of all is that brake rotors do not warp. The second problem is that replacing a brake rotor with a new brake rotor or machining the rotor on a bench lathe will only fix the problem temporary. The problem will almost always re-occur after a period of time, thus necessitating further repairs. Brake rotor disc thickness variation or excessive lateral runout, as well as drums that are out of round can cause vibrations and pulsations in the brake pedal and/or steering wheel. Brake lining material transfer onto the rotor can also have an effect on this as well. "
But go ahead. Keep arguing. You guys are obviously more experienced and more knowledgeable than brake companies, or Carroll Smith. :madflip:

[Kelvin]

I just read a little about what was written on Carrol's site as well as stop tech. I think the point not mentioned is what was written in his book was copywirtten in 1975. [quote]

So what? Disc brakes back then haven't really changed much in today's cars, PLUS we're talking about 1986-89 hondas. If we were talking about porsche's with ceramic rotors, you'd have a point. If anything, the brake technology he was working with in the 1960s, 70s, and 80s is more advanced than the puny, simple brakes on our hondas, so your point doesn't really make sense at all. Also, I suggest reading all of it, but I doubt you will.

[quote]What was known then about casting/ metals /race cars cams motors is old news. Its 2007 almost every thing has changed as far as cars has changed.

Are you inferring that the average car uses rotors and calipers completley different from what was availabe in the 80s? How do you think casting 'cast iron rotors' has changed? I don't buy your 'hypothesis' here.


Stop tech does not sell cheap rotor.

For the 50th motherfucking time, THIS ARTICLE WAS NOT WRITTEN ABOUT STOPTECH PRODUCTS. It was written about brake rotors, applicable to all disc brakes that use cast iron rotors.

[HostileJava]

Well I'm not saying your wrong, but if I was a brake rotor company I'd publish articles saying that brake shudder is the fault of the driver and/or pads and not the fault of the rotor.

[Kelvin]

ok how about this.............
At what temperature does cenemtite form? (im not reading al the links)
Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.
They can if they have uneven pad deposits, as the 'high spots' of pad material will lightly scrape your pad with every revolution, gradually building more and more heat. Your rotors will not be 'glowing orange', but small, localized areas will be heating up MUCH more than everything else. Don't believe me? Rent on of those IR thermometers, and shoot it at different parts of your rotor. They'll read different temperatures. Now imagine a high spot that hits your pads more than eveyrhting else else does. It will be the hottest.


Well I'm not saying your wrong, but if I was a brake rotor company I'd publish articles saying that brake shudder is the fault of the driver and/or pads and not the fault of the rotor.
That IS what they are saying. They said it is the result of OVERHEATED PADS RESULTING IN UNEVEN PAD DEPOSITS RESULTING IN LATERAL RUNOUT WHICH CAN RESULT IN CEMENTITE.
Fucking christ. I give up on this thread. :slap:

PS: Santa is real too! I have many witnesses who can claim to it! They will provide personal experiences of waking up, and having presents magically delivered under their tree! They KNOW he is real, and have seen evidence! Even the cookies were eaten!

I'm guessing the people who belive in warped rotors are the same people who believe that god controls everything, like the wizard of oz.

[HostileJava]

That IS what they are saying. They said it is the result of OVERHEATED PADS RESULTING IN UNEVEN PAD DEPOSITS RESULTING IN LATERAL RUNOUT WHICH CAN RESULT IN CEMENTITE.
Fucking christ. I give up on this thread. :slap:

No, actually it's not. I'm saying if I was a rotor company I'd publish articles that looked favorable. Those favorable articles may indeed be correct, but that's not for me to judge. That's all I said, I did not in fact say anything stating you were wrong or right. And stop double posting.

Edit: I reread your post and I think you misunderstood my post. My point being there not going to publish somthing that makes there product look bad. Comprende?

[Ls1-Inside]

PS: Santa is real too! I have many witnesses who can claim to it! They will provide personal experiences of waking up, and having presents magically delivered under their tree! They KNOW he is real, and have seen evidence! Even the cookies were eaten!
I'm guessing the people who belive in warped rotors are the same people who believe that god controls everything, like the wizard of oz.
:wtf: are you talking about?
This is the 2nd time you've posted a completely childish answer and it speaks worlds about your credibility.

"(In most cases)" does not mean ALWAYS. Figure that out!

You're cracking me up Kelvin

I can't stand replying to your posts any more. They're obnoxious, annoying, incorrect, repetitive of useless/misguided information, and frankly wrong.

You're taking accurate information out of context and trying to apply it to everything while manipulating it to make it say what you want and completely misinterpreting it. Then you're switching what you're talking about left and right: At first it's All Brakes (race cars or daily drivers) then it's Race cars only, now we're just talking about 80's Honda's? Which one is it? You don't know. You're answers don't apply to everything. Your absolutes are absolutely incorrect. And you're arrogance and stubbornness is wildly disturbing.
You won't accept simple physics, you take a "In Most cases" to mean "ALL THE TIME" and preach it, you attack members, and lace every reply deeply with sarcasm, you repeatedly post multiple replies instead of using the "Edit/Modify" functionality, you refuse to address simple questions with direct answers, you cloud up your answers and continuously use typical Internet-Troll tactics, i can go on about all the things wrong with just you alone. And all of that i can determine without even addressing all the things you're wrong about regarding brakes.

If this is offensive it's meant to be, if you're done with this thread I say 3Geez is better for it. If you never post another thread in here again this community will continue to grow, learn, remain open minded to new discoveries, and accept the facts of life as a healthy community of car enthusiasts should.

I would recommend you find another forum to preach to, and find some underlings and subordinates that will tolerate your childish mannerisms and worship you as the god you seem to think you are. I'm currently looking for the ignore functionality in the forum so i don't have to suffer the agony of reading another post from you.

Continue doing yourself a disservice by posting and spreading your inaccurate interpretations of automotive engineering and you'll only prove to me how obviously stubborn and confused you really are.

-Dan

[Oldblueaccord]

"This message is hidden because Kelvin is on your ignore list"



You can just add him to your ignore list its under prefences


wp

[Ichiban]

You are the one claiming santa, not us. I warped metal today with an oxy-fuel cutting torch. And my training and knowledge is the same of everyone else who works metal for a living, the people who make brake parts are part of that everyone else. Brake parts must conform to the same basic principles of the material they are made from.

At school we have carried out labs to test and check for every material condition I've spoken about. We heat different steels, cool them, cut them, wash them with an acid solution and then LOOK at the resulting formations. I have MADE and SEEN cementite, martensite, bainite, pearlite etc. With my own eyes and a torch, and some basic instructions. I was trained to UNDERSTAND these features because they are pivotal to a career in machining. I have to be able to form, change, modify and understand all of these phases of metal intimately.

Then you come along claiming "cementite" in a matter that is totally out of context to what I know to be true. You claim "cementite magically appears" in a manner that is actually contrary to it's true behavior, no reasons, it just is. While my knowledge is based on processes, change and development within the material, yours is an arbitrary "Carrol Smith said it, it must be true".

I'm amazed that not only would you call my knowledge and training into question, but you'd insult me and my ability to excel at my career. I hope you find Santa.

[Kelvin]

Sure thing Bill Nye. You obviously know more than Carroll Smith, and brake companies. I forgot.

[Ls1-Inside]

"This message is hidden because Kelvin is on your ignore list"
You can just add him to your ignore list its under prefences
wp


Thanks - He's been added.

:cheers:
Dan

[Oldblueaccord]

No, actually it's not. I'm saying if I was a rotor company I'd publish articles that looked favorable. Those favorable articles may indeed be correct, but that's not for me to judge. That's all I said, I did not in fact say anything stating you were wrong or right. And stop double posting.

Edit: I reread your post and I think you misunderstood my post. My point being there not going to publish somthing that makes there product look bad. Comprende?

Thats what I thought when I posted that stop tech sells rotors and they aint cheap at least by my standards.


I like Stop tech but he hurt himself in my eyes by directly contradicting what he writes in that brake test in Sport compact car. He writes about bedding in brakes correctly and list his ways but in the article his set up was not working so he "rebed them in quickly by heating the brakes until they smoked" thats a paraphrase by me. He did that in one pass.

Basically he thru out everything he had written on his website and did it the way everyone else does. And of course his brake kit still didn't stop in a shorter distance then a stock good pad/rotor setup does after 10 repeated trys.


wp

[Ichiban]

Sure thing Bill Nye. You obviously know more than Carroll Smith, and brake companies. I forgot.


Education or advertising, I see you've made your choice. I've made mine.

[2ndGenGuy]

No, actually it's not. I'm saying if I was a rotor company I'd publish articles that looked favorable. Those favorable articles may indeed be correct, but that's not for me to judge. That's all I said, I did not in fact say anything stating you were wrong or right. And stop double posting.

Edit: I reread your post and I think you misunderstood my post. My point being there not going to publish somthing that makes there product look bad. Comprende?

Welcome to my world, HostileJava. :welcome:

He's going to continue to tell you that you're wrong and that you're illiterate and that Carroll Smith knows more than everybody. He's going to keep saying "ALL RUNOUT IS UNEVEN DEPOSITS WHICH CAUSE CEMENTITE FORMATIONS" despite all of the evidence that proves that he is wrong. Despite COMMON SENSE that proves that he is wrong. Despite SCIENTIFIC FUCKING PROOF that he is wrong.

And he won't debate our points, he won't ever come back and do a point-by-point analysis of our points. He'll just keep name calling and telling us that we're idiots.

And to quote the article that HE linked us to:


What causes 'Warped Rotors'?
Typically warped rotors are caused not by a failure of the rotor itself.
Warped rotors (in most instances) are caused by the brake pads being operated at temperatures outside of their specified range. When the pads get too hot the pad material actually melts and 'fuses' itself to the rotor surface and creates a 'bump' on the surface of the rotor. In most cases this is not noticeable to the naked eye. This creates an annoying vibration when the brakes are applied. The only solution to this is turning (grinding) the rotors or installing new rotors.
We do not recommend turning rotors: It removes additional metal and reduces the the thermal capacity of the discs.
The best way to combat this condition is to use GOOD QUALITY street performance brake pads which have a higher operating temperature range.
Properly 'bedding-in' the pads and discs is a must.
Tip: Our Temperature Indicating Paint Kit may be useful in determining the
correct brake pad compound(s) for your application:

It doesn't say rotors don't warp. Do you comprehend what IN MOST INSTANCES MEANS? That article also directly contradicts YOU Kelvin. It says "We do not recommend turning rotors". Again, you've proven yourself wrong, and twisted this information into mis-information. It says NOTHING about cementite. Nothing! Do you see CEMENTITE in there? Did you even read my post about pad deposits? I said YES UNEVEN PAD DEPOSITS HAPPEN but it DOES NOT CAUSE CEMENTITIE!

Again, the other article mentions NOTHING about cementite formation. It says rotors don't warp, but wear into high and low spots. The article calls is Disc Thickness Variation (DTV). Again, they say DON'T USE CHEAP ROTORS.


Replacing a rotor with excessive DTV with another new rotor will only correct the problem temporarily, because eventually the associated LRO with the new rotor will lead to DTV over a period of time, and the problem repeats itself all over again. Machining a rotor with excessive DTV on a bench lathe will only temporarily correct the problem because the rotor is being machined true to the bench lathes spindle and not the spindle on the car, plus the spindle on the bench lathe has its own runout.

Cementite? No mention of it. A good theory? Yes I think so. It makes WAY more sense than your theory of Cementite. Perhaps I'll look into it more, but DTV is mostly the same theory and principles as rotor warpage. They even say that DTV will come BACK with BRAND NEW ROTORS! NOT UNEVEN PAD DEPOSITS. Read your own articles.

Kelvin, do you know why you're getting pissed off? Because your points are being shot down 1 by 1. Instead of coming back point by point (like a grown man) you come back like a little kid and accuse US of not reading anything. You're the one who didn't read! The articles YOU posted proved you wrong and you've proven yourself wrong.

I haven't made it for 2 years on this forum by spreading BS and being a closed-minded person and not reading and listening to what people have to say. That tends to piss people off and get you banned.

[Kelvin]

Advertising? For what? Nothing I've posted has anything to do with specific products. It's all general information, applicable to parts from any company.

[2ndGenGuy]

Sure thing Bill Nye. You obviously know more than Carroll Smith, and brake companies. I forgot.

Way to back yourself up with facts. BTW, those brake companies proved YOU wrong and made no mention of cementite.

[Kelvin]

Fuck you. All you've done is attack me, and I've had enough of it. Get off your god damn high horse. I know what I'm talking about. Bill Nye doesn't. You've proven that you're unable to read even SIMPLE examples, and confuse 'crappy' with 'expensive'. You refuse to acknowledge the information I've presented, and label it as advertising, even though it has nothing to do with a specific product. HIGH TEMPERATURE PADS will not cause uneven pad deposits, because they are designed to work up to extremely high temperatures, thus they do not unevenly transfer pad material until really high temps. This idea is far too complex for your feeble brain to figure out, and you STILL continue to harass me, call me names, and attempt to discredit the information I've presented, without realizing that you're making yourself look like a fool. Fucking BRAKE ROTOR COMPANIES explain that high temperature pads will help prevent uneven pad deposits, and STILL you dispute it.

Now it's time for me to call you a name:

You sir, are a complete fucking idiot.

[Kelvin]

Way to back yourself up with facts. BTW, those brake companies proved YOU wrong and made no mention of cementite.

Yep. This is all bullshit. You know more than them:

More articles from BRAKE ROTOR COMPANIES that claim rotors never warp:
http://www.raceshopper.com/tech.shtml#warped_rotors

"Warped rotors (in most instances) are caused by the brake pads being operated at temperatures outside of their specified range. When the pads get too hot the pad material actually melts and 'fuses' itself to the rotor surface and creates a 'bump' on the surface of the rotor. In most cases this is not noticeable to the naked eye. This creates an annoying vibration when the brakes are applied"

This is exactly what I said above. Shitty pads with a low maximum temperature= uneven pad deposits. Yet still, certain people argue and claim that high temperature pads will work exactly the same as shitty organic pads. Why? Who knows. Some people buy tornado fuel savers.
Here's another BRAKE MANUFACTURER that claims that rotors never warp, and I'm guessing they know more about rotors than certain so called 'experts' on this forum.

http://www.performanceoiltechnology.com/brakingsystems.htm

"The problem with this diagnosis and repair procedure is that first of all is that brake rotors do not warp. The second problem is that replacing a brake rotor with a new brake rotor or machining the rotor on a bench lathe will only fix the problem temporary. The problem will almost always re-occur after a period of time, thus necessitating further repairs. Brake rotor disc thickness variation or excessive lateral runout, as well as drums that are out of round can cause vibrations and pulsations in the brake pedal and/or steering wheel. Brake lining material transfer onto the rotor can also have an effect on this as well. "
But go ahead. Keep arguing. You guys are obviously more experienced and more knowledgeable than brake companies, or Carroll Smith. :madflip:

[Kelvin]

More brake companies mentioning cementite, and proving 2ndgenguy wrong:

http://www.powerbrake.co.za/downloads/tech_01_judder.pdf

"Even the best quality discs money could buy would have developed the same brake judder. Here’s why.... As explained above, the disc was continually coming into contact with the pads at the point of maximum run-out first. If abrasive pads were being used this area of the disc would wear down quicker than the rest of the disc surface causing DTV, which is felt as an intrusive judder. If adhesive pads were being run then the pads would have deposited more material on the initial contact point (the area of max. run-out) than on the rest of the disc surface. Again this leads to DTV and brake judder.

"It gets worse! Once you have the development of DTV the surface of the disc will begin to heat unevenly. The high spots will get extremely hot compared to the rest of the disc. When the temperature around these high spots reaches 650 – 700°C. the cast iron in that area will change structurally and transform into a material called Cementite. Cementite is far harder than the cast iron of the unaffected parts of the disc and will therefore wear considerably less as the disc wears down with use.
Cementite also has very poor heat sink properties and will therefore continue to run extremely hot resulting in the rapid spread of the Cementite formation deeper and deeper into the disc. As a result the DTV will get progressively worse with time until it becomes literally unbearable to use the brakes. Depending on the pads used and the driving style of the vehicle owner this process could take 1000 – 6000 kilometers to develop and, NO, the initial run-out will not necessarily be felt by the driver. Hence the confusion and clinging to the concept of brake discs “warping”

[Ichiban]

Cementite doesn't do that. Go buy a tornado. And some Amsoil.

"Cementite formations are normally visible as blue/black areas
on the disc surface."

Nope, That is iron oxidizing. Remember the tempering colors I was talking about? Iron forms different oxides at different temps. It has nothing to do with carbon or cementite. The website is wrong.

[Kelvin]

I think you should apply to those brake companies. You're obviously more intelligent than everybody at those companies combined. :)

So the question is... do you trust a self proclaimed metal expert? Or brake companies and Carroll Smith? Hrm.....

[Ls1-Inside]

Cementite doesn't do that. Go buy a tornado.

I dont know what Kelvin said - but I'm sure it's wrong again.

LOL

I just read a bunch about it from various sites.

None of them are actually going out and claiming rotors never warp. They're saying Vibrations are USUALLY not from warped rotors, and are USUALLY from unevenly deposited pad material.

Rotors still occasionally warp. Period, the end.

A PADS operating temperature has nothing to do with unevenly deposited material. ANY pad operating over it's designed temperature is going to deposit it's material to the rotor. This doesn't necessarily mean an uneven deposit. Coming to a stop on a red hot rotor will however, transfer a bump... Even high quality pads will transfer this material if you come to a stop on an over heated pad. Even so - that bump is not cementite... That Bump transfer is the Operator's fault, not the pads...


I doubt Kelvin will ever accept things like Rotors occasionally warp. We're all believers of the vibrations primarily coming from unevenly distributed pad material... we all believe that. We all don't believe that the Unevenly Distributed pad material magically transforms into cementite during daily driving conditions. We all don't believe that Brake rotors are somehow immune to warping through some miracle of god. We all don't believe that Carol Smith intended his "Experience" with rotors to actually dictate the metallurgy principals that all metals are bound to!

I wonder how long Kelvin this thread will go before its locked.

-Dan

[guaynabo89]

They can if they have uneven pad deposits, as the 'high spots' of pad material will lightly scrape your pad with every revolution, gradually building more and more heat. Your rotors will not be 'glowing orange', but small, localized areas will be heating up MUCH more than everything else. Don't believe me? Rent on of those IR thermometers, and shoot it at different parts of your rotor. They'll read different temperatures. Now imagine a high spot that hits your pads more than eveyrhting else else does. It will be the hottest.


yeah but the air flowing through the rotors would still keep the rotor from reaching that 700+ celcius dont you think!


I'm guessing the people who belive in warped rotors are the same people who believe that god controls everything, like the wizard of oz.

God doesnt control everything, he just gave you life and lets you choose your way! ;)

[Ichiban]

I just googled "cementite in brake rotors"

Not only did I find almost all of kelvins references, but I found people claiming that cementite comes out of the brake pads!!! as well as 2 people on forums disputing cementite "formation" due to it already being there, having formed as the pour solidified.

[HostileJava]

OK then.