Difference between Brembo blanks and standard parts store rotors?

failboat wrote: arent $11-15 Napa Blanks pretty popular with the Spec Miata crowd?

I don't think Spec Miatas use brakes, they just use other Spec Miatas.

Keith Tanner wrote:

failboat wrote: arent $11-15 Napa Blanks pretty popular with the Spec Miata crowd?

I don't think Spec Miatas use brakes, they just use other Spec Miatas.

heh, you said Spec Pinata....

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

think how much heat it would take to turn the rotors cherry red … and enough to keep them red after you released the pressure from the pads … then you'd have to cool them immediately to get any/much warping

good read from Stop Tech about the myth of warped rotors:

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

on the track corvettes, ive tried the cheap napa Chinese rotors, and the brembo, and the GM dealer replacements. all on Z06 C5 vettes, all with wildwood H pads. all with the same three drivers.

all the rotors crack withing 9 days at CMP. no brand had any appreciable lifetime difference. one driver mid run group hpde, two TT guys.

on the street, with aggressive metallic pads, the more expensive rotors (brembo in this case) seem to wear more evenly over the life of the pads.

again, anecdotal, but a fairly well controlled anecdote.

Timeormoney wrote:

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

+1

only true if you have sufficient rotor heat capacity for the type of driving you're doing and/or the weight of your car (which not all cars do). Our e30 frozen rotors at VIR definitely warped (probably due to heat+puddles on track).

Years ago when I worked at Autozone, the Duralast rotors for some cars would frequently show up in Brembo boxes. I believe it was mostly German cars, but seemed mostly random with different boxes for the same part numbers. The Brembo rotors for my Miata were dirt cheap.

irish44j wrote:

Timeormoney wrote:

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

+1

only true if you have sufficient rotor heat capacity for the type of driving you're doing and/or the weight of your car (which not all cars do). Our e30 frozen rotors at VIR definitely warped (probably due to heat+puddles on track).

I bow to the depth of knowledge of the members here … I'll be sure to send this info to Stop Tech so they can revise their "white paper" on the warped rotor myth (see article link above)

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

Huh? So even though it's been examined and IS warped, it isn't really warped because you said it wasn't?

I can tell a difference when I put a drill bit to them. Brembo nice long steel strips the Chinese small chips and dust. That being said I have yet to see a cracked rotor in all the ones I have drilled. I never turn them just replace [$10-12 and two trips into town = cost of new rotor delivered].

My Cherokee and c900 both benefited greatly.

I bought a rotary table for my drill press so I can drill them faster.

ebonyandivory wrote:

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

Huh? So even though it's been examined and IS warped, it isn't really warped because you said it wasn't?

read the linked article … these folk are experts … I tend to believe folk that make their living doing something as opposed to folk that pick up on buzz words/phrases

it IS possible that a set of rotors would have excessive run out straight from the factory … but this would be a QA problem not the fault of the user

wbjones wrote:

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

think how much heat it would take to turn the rotors cherry red … and enough to keep them red after you released the pressure from the pads … then you'd have to cool them immediately to get any/much warping good read from Stop Tech about the myth of warped rotors: http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Since you either conveniently missed this or purposely chose to ignore it.....

Bobzilla wrote: Undersized rotors will warp quickly. The old Elantra rotors were 9.9" rotors (with drum rears)and extremely thin (bulletin released warning to not turn them as there was 1mm in extra thickness between "new" and minimum) in a 2900 lb empty car. a couple of Interstate panic stops with a passenger of normal size would have the rotors so blue you'd swear they were painted. They were warped. I put multiple rotors on that car even after switching to HPS pads. It wasn't until I stepped up to the 11" Sonata rotors with Tib calipers that it stopped warping them and making pretty colors.

I'm willing to believe it's not really warped even though a brake specialist said it was (I'm not being sarcastic here). But If this uneven deposition of material caused a "warped feeling" then would it not diminish after hundreds of miles as the extra material wore down?

And to Bobzillas point above, this is a 5,000 lb truck with rear drums that at the time needed new drums AND shoes, making a similar "outmatched" scenario where the fronts were trying to do way more than you'd normally expect of them.

ebonyandivory wrote:

turboswede wrote: In reply to ebonyandivory: No you don't. You have uneven material build up on the rotors due to poor brake pad bedding techniques or cheap pads.

Huh? So even though it's been examined and IS warped, it isn't really warped because you said it wasn't?

Well, you know. internet experts and all. EVERY situation is the same as the one they have knowledge on. EVERY. SINGLE. ONE. The world completely black and white and there's no grey's or colors involved. yadda yadda....

In reply to Bobzilla:

I just find it funny that I've been hearing the term "warped rotors" as long as I've been interested in cars/trucks/bikes (30+ year) and I'm being told that almost none of it is true even though I've had rotors turned several times and was told that there was warpage each time.

I've turned more than a few myself, both professionally and personally. If it was uneven pad material deposits, when turned it sure looks an awfule lot like metal shavings coming off and not organic pad material.

But I'm sure I'm 100% wrong because a "professional" selling their own brand of products says so.

In reply to Bobzilla:

And since I read the article, and high temperatures causing deposition of pad material onto the rotor seemed to be the culprit they keep referring to, what explains the "warpage" resulting from ONE STOMPING of the brakes for literally under one second (like when a dog runs into the road) and doesn't build up any appreciable heat?

This happened to me. Imagine the quickest, hardest stomp of the brake pedal one could muster. It's under one second and results in the vehicle barely slowing from say 40mph to 37mph.

And again, due to no time and the fact that I can't have my truck down to replace the rotor, Ive put about 2,000 miles on that rotor, wouldn't those miles have "turned" the rotors some and reduced the pulsation if it was really just built up material?

I will not pretend to be any kind of brake expert but I will add this. After following the bedding in the Stoptech article linked above like 5 years ago I have not had a single "warped" rotor on any of my cars with the caveat that it has been only street driving.

ebonyandivory wrote: Ive put about 2,000 miles on that rotor, wouldn't those miles have "turned" the rotors some and reduced the pulsation if it was really just built up material?

Not necessarily.

I have a consistent problem with "warped rotors" on my wife's TSX. This was with the OEM pads/rotors as well as Akebono Euro pads and Brembo rotors. I know the rotors aren't actually warped; it never gets driven hard enough to make the brakes hot, ever. It is some kind of material buildup, even though I properly bedded the brakes when I replaced them. In fact, they didn't really need replacing when I did them; I was just tired of the wobbly steering wheel and pedals under moderate braking. Now, 20,000 miles later, they feel warped again despite the change of manufacturer for both rotors and pads. Something about her driving profile, or the TSX's caliper setup, makes them deposit crud on the rotors. And once the initial crud is there, it scoops off a little pad material every day and adheres it to the growing blob.

I should probably pull them off and get them dressed somewhere.

I don't doubt that what may appear to be a warped rotor may well be unevenly deposited pad material but to be told that my warped rotor definitely wasn't warped by someone on an Internet forum just didn't sit well with me.

Especially when so many assumptions had to made to come to that conclusion. I was just wrong and uninformed because someone said so. It doesn't work that way.

Oh, agreed, completely.

Rusted_Busted_Spit wrote: I will not pretend to be any kind of brake expert but I will add this. After following the bedding in the Stoptech article linked above like 5 years ago I have not had a single "warped" rotor on any of my cars with the caveat that it has been only street driving.

I've used proper bedding procedures for 20 years. Only experienced warped rotors on a very few cars, one being the previously mentioned Elantra, the other being the truck (after towing the first car/trailer with no trailer brakes, rotors were blue.) The truck was fixed with a better pad and re-adjusting the rear drums and haven't had a problem since. The Elantra didn't care WHAT you did. When you're that seriously undersized for the vehicle, nothing in the world is going to make them last.

I'm not saying that a lot of rotor vibration doesn't come from pad deposits. I'm pointing out the fallacy of believing that is the ONLY option. There are cars that have brakes too small for the vehicle that do physically overheat and warp their rotors. There are times when more weight and improperly maintained/adjusted brakes can overheat and warp the front rotors.

Both of my E21's would warp the rotors. Of course they were small, solid, non vented rotors. I verified the run out of the new rotors before put them on the '80. One trip to the dragon and that same old pulsation came back. Took them back and verified warping, like Bob said some brakes are just under spec'd and solid rotors are easy to warp.

In reply to Bobzilla:

You are correct and if I came across as implying that was the only reason I did not mean to.

Rusted_Busted_Spit wrote: In reply to Bobzilla: You are correct and if I came across as implying that was the only reason I did not mean to.

I knew that. You aren't the one relying on a stoptech article to prove everyone else wrong. There's good information there. But there's also more to it.

It wouldn't be GRM without a healthy thread derail!

I think I'll give the rockauto rotors a try.