Question about brake wear - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-02-2011, 11:51 AM   #1
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default Question about brake wear

I just recently purchased the Carbotech XP10/XP8 combo for my 1990 NA with the 02 Sport brakes, and installed them on the current rotors I had on the car, which were fairly new and in great shape.

As I did with my previous track-car, I have been street driving on these pads for the past week to scrub the previous pad material off the face of the rotors, and will be bedding them in at my upcoming DE at Sebring this weekend.

One thing I have noticed is the front rotors seem to have cleaned off all the previous material from the face of the rotor, it is a clean, silver metal tinge (previous color was blue-ish), but on the rear, only the outer 40% of the rotor has the clean, silver color, and the inner area is still blue-ish. Based on how the pad is "cleaning" the rotor, it seems like the pad contacts the rotor with more pressure on the outer-edge of the rotor? Is this normal for a single piston, "clamp-style" caliper?

My previous track-car had 4 piston calipers all around, and the wear was completely even, so I have nothing to compare this to.

Thanks all,

-Scott
smbstyle is offline   Reply With Quote
Old 11-02-2011, 11:55 AM   #2
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Not sure about rear sport brakes exactly, but we don't use the full rotor surface in the rear for braking. At least the pad doesn't contact on the full surface.

There is also the common confused sport rotors with the regular NB rotors, so make sure you are using the correct rotors in the rear.

Posting up pictures might help. are you experiencing uneven wear on your pads (silly question considering you just put them on, but what about the old pads?)
Seefo is offline   Reply With Quote
Old 11-02-2011, 12:02 PM   #3
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default

Quote:
Originally Posted by Track View Post
Not sure about rear sport brakes exactly, but we don't use the full rotor surface in the rear for braking.

There is also the common confused sport rotors with the regular NB rotors, so make sure you are using the correct rotors in the rear.

Posting up pictures might help. are you experiencing uneven wear on your pads (silly question considering you just put them on, but what about the old pads?)
Ah okay that makes sense then; I didnt know they dont use the full rotor surface.

I'll post up pics tonight, but when measuring the rotor thickness, as well as where the pad was contacting the rotor, it appears the rotors are for the correct application.

The pads that came off had perfectly even wear, each pad was level, and each side was wearing evenly. Not having any problems with any one corner locking up under heavy braking, it's not pulling to one side, etc.

I'm also figuring that the rears will take longer to clean the old pad compound off b/c it is a less aggressive pad and the brake bias is more towards the front anyways.
smbstyle is offline   Reply With Quote
Old 11-02-2011, 12:06 PM   #4
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

The rotor surface is not flat, but it will be after you track it a little bit.
hustler is offline   Reply With Quote
Old 11-02-2011, 01:15 PM   #5
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

check out the rotors in this picture:

Rears:


Fronts:


Is that what you are experiencing pretty much (with the rust)?
Attached Thumbnails
Question about brake wear-img_1898.jpg   Question about brake wear-img_1899.jpg  
Seefo is offline   Reply With Quote
Old 11-02-2011, 01:21 PM   #6
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default

Quote:
Originally Posted by Track View Post
check out the rotors in this picture:

Rears:


Is that what you are experiencing pretty much (with the rust)?
Yep, thats it; i had no idea the rears only used a portion of the rotor. wild.

Also, the rear rotor on the left side in that pic, you can see the two different color bands (outside blue-ish, inside silver-ish), thats exactly what mine looks like right now, expect the inside is blue-ish and the outer area is silver.
smbstyle is offline   Reply With Quote
Old 11-02-2011, 02:13 PM   #7
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

yea, I see what you are talking about. Not sure exactly about the different colors. I know mine have some slight color gradienting due to heat. thats what I would blame it on, but that's probably not accurate. I can see the pad material having an effect on that, but if you like I can take pictures of my rear rotors (xp8s on 1.8 brakes) and you can compare them to yours. mine have had quite a bit of track time on them and are daily'd between events.

all else fails, take a flapper disk to the rotors and use a micrometer/dial indicator to get things worked out. Cheap man's resurface.
Seefo is offline   Reply With Quote
Old 11-02-2011, 02:34 PM   #8
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,353
Total Cats: 1,322
Default

Quote:
Originally Posted by smbstyle View Post
I just recently purchased the Carbotech XP10/XP8 combo for my 1990 NA with the 02 Sport brakes, and installed them on the current rotors I had on the car
Huge mistake. Take the rotors off and have an auto shop resurface them, or replace all 4 rotors all together. You CANNOT install Carbotechs on used rotors - you will blue the rotors from excess heat and wear through the pads much, much faster than you otherwise would.

Carbotechs are ---- about break-in procedure - you have to follow it down to the letter.
Savington is online now   Reply With Quote
Old 11-02-2011, 02:45 PM   #9
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

^I won't argue against that Savington, as thats what I would do (and have done). but I have heard of many people using carbotechs on rotors with old material. took a while, but it worked it self out after a month or two. What have you seen happen when you don't do that, just curiosity on my part.

but yea, Carbotechs are quite ----, but well worth the trouble.
Seefo is offline   Reply With Quote
Old 11-02-2011, 03:25 PM   #10
Elite Member
 
Join Date: Jul 2007
Location: Little Rock, AR
Posts: 3,109
Total Cats: 127
Default

You can use carbotechs on old carbotech used rotors but not with any other pad compound. If your in a pinch you can us a DA and sand them clean. After you bed them in the rotor will be all kinds of rainbow blue weird colors.
jacob300zx is offline   Reply With Quote
Old 11-02-2011, 03:38 PM   #11
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default

Quote:
Originally Posted by Savington View Post
Huge mistake. Take the rotors off and have an auto shop resurface them, or replace all 4 rotors all together. You CANNOT install Carbotechs on used rotors - you will blue the rotors from excess heat and wear through the pads much, much faster than you otherwise would.

Carbotechs are ---- about break-in procedure - you have to follow it down to the letter.
I got this article from a tech at Performance Friction, and this is why I decided to re-use my old rotors and "clean" the surface of them with the abrasive Carbotech pads....

It worked great with my PFC 01 pads on my previous car, so that's why I figured I could do it with the Carbotechs, I can't imagine it works fine for all of these other brands EXCEPT Carbotech.... I shot an email to Danny at Carbotech to see what he thinks.




http://www.essexparts.com/learning-center/swapping_pads


My Daily Driven Brake Lathe

If you read my piece on choosing brake pads, you know that most race or track pads are very abrasive when driven cold. In other words, rather than transferring to the rotor face when cold, they primarily generate friction by scraping the rotor face. We're going to use that trait to our advantage, and scrape the old pad material off of our disc faces. We'll do so by performing a series of stops, without ever allowing the race pad to get hot enough to transfer to the rotor. Some compounds are obviously more abrasive than others, but generally speaking, most race compounds with a high coefficient of friction will work for this procedure. I've always used Hawk's Blue compound, which is a safe bet at a fairly affordable price, and comes in a wide range of applications. When going to the track, I usually keep a set on hand in my toolbox in case I need to clean up my rotors.

The easiest way to clean up your rotors with race pads is to simply drive them around as your daily driver for a few days. Let's go back to our earlier street-to-track example. You did your bed-in with your Hawk HPS street pads. You have a track day coming up in a week. You plan on using Ferodo DS1.11 for that event. The easiest way to prep your rotors prior to bedding in your DS1.11's is to simply swap in the DS1.11's the weekend before the event and drive them around on the street. In normal daily driving, you'll never get the race pads hot enough to begin transferring onto the rotors. During that time they'll be operating in an abrasive manner, scraping the HPS material off of your discs. By the time your event weekend rolls around, you should be back down to bare, shiny metal on your discs. Sure they won't be quite as clean as if you were using brand new rotors, but you should be able to get just about all of the old pad material off of the rotors, providing the perfect canvas for laying down a layer of race compound through a proper bed-in.
smbstyle is offline   Reply With Quote
Old 11-02-2011, 03:54 PM   #12
I haz no trubo
iTrader: (2)
 
Oscar's Avatar
 
Join Date: Jan 2007
Location: Bolton, UK
Posts: 3,021
Total Cats: 114
Default

Looks like an extremely ghetto way of cleaning rotors. In my experience, carbotechs don't eat rotors when cold so I wonder how 'clean' you get your rotors by using them as daily driven sandpaper. I don't know if you can ruin fresh XP10/XP8s like that, but I wouldn't take the chance.
Oscar is offline   Reply With Quote
Old 11-02-2011, 03:58 PM   #13
Elite Member
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,009
Total Cats: 583
Default

Seems more logical to have a dedicated set of track pads and rotors along with a dedicated set of street pads and rotors. For the most part, rotors are less expensive than pads.

Doing the above procedure compromises you in two way -- obviously at the track ("won't be quite as clean . . ." -- I love the precise lingo) + while you're running around on the street doing lathing operations, you can't stop as well as you might need to.

Doesn't seem worth it to me.
hornetball is online now   Reply With Quote
Old 11-02-2011, 04:02 PM   #14
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default

Quote:
Originally Posted by Oscar View Post
Looks like an extremely ghetto way of cleaning rotors. In my experience, carbotechs don't eat rotors when cold so I wonder how 'clean' you get your rotors by using them as daily driven sandpaper. I don't know if you can ruin fresh XP10/XP8s like that, but I wouldn't take the chance.
ghetto AND efficient. worked great for me with my PFC pads in the past.

again, like i said, i'll see what Danny has to say. if he says that process wont work with their pads, i'll gladly have mine resurfaced or throw on new rotors. just dont want to spend money on it if i dont have to.
smbstyle is offline   Reply With Quote
Old 11-02-2011, 04:06 PM   #15
Junior Member
Thread Starter
 
Join Date: Aug 2011
Location: Lakeland, FL
Posts: 76
Total Cats: 0
Default

Quote:
Originally Posted by hornetball View Post
Seems more logical to have a dedicated set of track pads and rotors along with a dedicated set of street pads and rotors. For the most part, rotors are less expensive than pads.

Doing the above procedure compromises you in two way -- obviously at the track ("won't be quite as clean . . ." -- I love the precise lingo) + while you're running around on the street doing lathing operations, you can't stop as well as you might need to.

Doesn't seem worth it to me.

these pads actually have better cold bite than my mazdaspeed miata pads do.
smbstyle is offline   Reply With Quote
Old 11-02-2011, 04:08 PM   #16
Senior Member
iTrader: (4)
 
Join Date: Jan 2008
Location: Falls Church, VA
Posts: 1,367
Total Cats: 16
Default

Quote:
Originally Posted by Track View Post
but yea, Carbotechs are quite ----, but well worth the trouble.
After running through a couple sets of the XP10/8 combo I am growing weary of dealing with them. No problems with heat or fade on track (stock power), but the transfer layer with these pads will give you **** if you look at it cross-eyed. I installed mine on fresh rotors (Carbotech's instructions are explicit in this regard, some of you should try reading them) so there would be no issues from incompatible pad material, bedded them properly, etc. Even with a transfer layer that is initially even, over the course of a track weekend I've had it either build up or wear down (or combination of both) in an uneven manner to the point of being visually obvious on the rotor face, and causing annoying pedal pulsations. I generally like the pads except for the transfer layer BS, but that's kind of like saying the federal budget is generally in good shape except for all the debt.
ScottFW is offline   Reply With Quote
Old 11-02-2011, 04:14 PM   #17
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Quote:
Originally Posted by ScottFW View Post
After running through a couple sets of the XP10/8 combo I am growing weary of dealing with them. No problems with heat or fade on track (stock power), but the transfer layer with these pads will give you **** if you look at it cross-eyed. I installed mine on fresh rotors (Carbotech's instructions are explicit in this regard, some of you should try reading them) so there would be no issues from incompatible pad material, bedded them properly, etc. Even with a transfer layer that is initially even, over the course of a track weekend I've had it either build up or wear down (or combination of both) in an uneven manner to the point of being visually obvious on the rotor face, and causing annoying pedal pulsations. I generally like the pads except for the transfer layer BS, but that's kind of like saying the federal budget is generally in good shape except for all the debt.
I haven't really experienced this to that degree. occasionally when I daily them, I can hear the noise changing as different parts of the rotor and pads are touching. This tells me the transfer layer isn't even, but I have zero pulsing on track and off track.

Perhaps you have an issue otherwise? I don't really know, this is my first set that I am wearing out completely.
Seefo is offline   Reply With Quote
Old 11-02-2011, 04:39 PM   #18
Senior Member
iTrader: (4)
 
Join Date: Jan 2008
Location: Falls Church, VA
Posts: 1,367
Total Cats: 16
Default

I don't know exactly what causes it, but it's happened on multiple (but not all) track weekends. I can't really explain it, but I'm moving on and will be running dedicated (separate) pad sets for street and track once the Wilwoods go on.

Also keep in mind that wearing out "completely" with Carbotechs does not mean "down to the backing plate." When you get down to a certain amount the rivets will start to contact the rotors and eat grooves into them. When you get to this point it will appear at a casual glance that you still have good pad material left. Try to milk too much life out of them and you'll be replacing rotors too. If you keep out of the rivets you can get 2 or 3 sets of pads to a set of rotors. The friction material is friendly in that regard.
ScottFW is offline   Reply With Quote
Old 11-02-2011, 05:35 PM   #19
Elite Member
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

good to know, I will be replacing mine pretty soon, about how soon do the rivets show up? I think I have about 3/16th left on the fronts.
Seefo is offline   Reply With Quote
Old 11-02-2011, 05:36 PM   #20
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,353
Total Cats: 1,322
Default

Quote:
Originally Posted by smbstyle View Post
I can't imagine it works fine for all of these other brands EXCEPT Carbotech.... I shot an email to Danny at Carbotech to see what he thinks.
It's actually really easy to imagine - Carbotechs are not a metallic-based compound like every other race pad, so you can't break them in like every other race pad.
Savington is online now   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Raleigh: Fiberglass headlight scope, 1.6L ECU, AFM, Hardtop latches, more bigmackloud Miata parts for sale/trade 13 09-22-2017 01:34 PM
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
15x10 - 15x11 6UL @ 949 Racing emilio700 Wheels and Tires 151 06-02-2017 03:36 PM
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:21 PM.