Cheap brake rotors
11-30-2006, 08:47 PM
#16
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Ah sweet! I need that tool. Any recommendations on brand / where to buy? What is that thing called? A brake rotor measuring tool? has to be a catchier name to it ...
Last edited by MirageMetallic; 11-30-2006 at 09:24 PM.
11-30-2006, 08:49 PM
#17
Nordschleife Master
Originally Posted by MirageMetallic
What is that thing called? A brake rotor measuring tool? has to be a catchier name to it ...
Last edited by LVDell; 12-01-2006 at 07:59 AM.
11-30-2006, 09:38 PM
#18
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I agree with Dell +3.
You can usually tell if the rotor needs replaced (for thickness) based on the depth of the "lip" at the outer edge. When it's past the limit it's pretty obvious. I wouldn't bother turning them as cheap as new ones are.
You can usually tell if the rotor needs replaced (for thickness) based on the depth of the "lip" at the outer edge. When it's past the limit it's pretty obvious. I wouldn't bother turning them as cheap as new ones are.
12-01-2006, 08:30 PM
#20
Race Car
Thread Starter
Originally Posted by MirageMetallic
Ah sweet! I need that tool. Any recommendations on brand / where to buy? What is that thing called? A brake rotor measuring tool? has to be a catchier name to it ...
12-01-2006, 11:28 PM
#22
Drifting
Originally Posted by MechanicalEng
your caliper reads 22.255mm in that picture, what is the original thickness of the rotor? I guess you need that to measure the 2mm of wear..
Thanks a lot
Thanks a lot
Since my 1997 Boxster is used, and I have the original front rotors, and 60k miles, I am not able to accurately measure the original thickness of my rotors.
But, I can measure the lip....
07-03-2007, 12:53 AM
#23
Instructor
I think I need to change my front rotors+pads since I can touch a lip on the rotor edges. Is the method below ok?
1. Buy a micrometer or vernier caliper.
2. measure the width at the lips/edge of rotor (from inner surface till outer surface)
3. measure the width just inside the lip/edge of rotor (from inner surface till outer surface)
4. see if the difference between #3 and #4 is 2mm or greater.
Now the rotors are ventilated. So am I supposed to measure from outer (or inner) edge till the middle gap or directly between the outer and inner gap?
My current understanding is that I'm given 1mm of wear on the inner surface and 1mm wear on the outer surface giving me 2mm total between the inner and outer surfaces of the rotor.
The next phase is how do I measure the pad thickness (not rotor thickness)? And what are the recommended limits? This is for an C2 996, OEM pads mostly.
Finally, where can I find pad options for the C2? This car is mostly street, so I'm taking the OEM route unless you guys have a better suggestion.
Cheers !
1. Buy a micrometer or vernier caliper.
2. measure the width at the lips/edge of rotor (from inner surface till outer surface)
3. measure the width just inside the lip/edge of rotor (from inner surface till outer surface)
4. see if the difference between #3 and #4 is 2mm or greater.
Now the rotors are ventilated. So am I supposed to measure from outer (or inner) edge till the middle gap or directly between the outer and inner gap?
My current understanding is that I'm given 1mm of wear on the inner surface and 1mm wear on the outer surface giving me 2mm total between the inner and outer surfaces of the rotor.
The next phase is how do I measure the pad thickness (not rotor thickness)? And what are the recommended limits? This is for an C2 996, OEM pads mostly.
Finally, where can I find pad options for the C2? This car is mostly street, so I'm taking the OEM route unless you guys have a better suggestion.
Cheers !
Last edited by Sids911; 07-03-2007 at 03:43 AM.
07-03-2007, 01:15 AM
#24
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I can't believe that the rotors do not have a "minimum thickness" spec engraved in them somewhere, this would be the first case I've ever heard of w/o this. I think that it must be a law, it's on every rotor and drum I've ever looked at.
The reason for changing rotors goes beyond strictly thickness, the real problem is that they get heat-cycled too many times and it changes the quality of the steel. (More brittle/hot spots/etc...). This is also related to thickness, they get too hot and warp.
All of these things obviously are amplified if you track the car or do any high-speed mountain driving where you really get the brakes hot and need maximum stopping and fade-resistance. My local track is the fastest in the west, (WSIR), but ironically is not a tough one on brakes. They stay reasonably cool there due to the layout of the course.
In regular freeway driving, frankly the 996 has so much more braking performance than most cars that therefore if you are running @ 80-90% braking performance you would probably be OK. Not for me, though. I need 100%. The brakes are always the most impressive thing on a 911, BTW.
The reason for changing rotors goes beyond strictly thickness, the real problem is that they get heat-cycled too many times and it changes the quality of the steel. (More brittle/hot spots/etc...). This is also related to thickness, they get too hot and warp.
All of these things obviously are amplified if you track the car or do any high-speed mountain driving where you really get the brakes hot and need maximum stopping and fade-resistance. My local track is the fastest in the west, (WSIR), but ironically is not a tough one on brakes. They stay reasonably cool there due to the layout of the course.
In regular freeway driving, frankly the 996 has so much more braking performance than most cars that therefore if you are running @ 80-90% braking performance you would probably be OK. Not for me, though. I need 100%. The brakes are always the most impressive thing on a 911, BTW.
07-03-2007, 01:04 PM
#26
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Originally Posted by wdonovan
If you have to buy a tool to measure the thickness, get a digital caliper rather than a micrometer. You'll get a lot more use out of it.
07-03-2007, 06:44 PM
#28
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Originally Posted by denishartigan
I can't believe that the rotors do not have a "minimum thickness" spec engraved in them somewhere, this would be the first case I've ever heard of w/o this. I think that it must be a law, it's on every rotor and drum I've ever looked at.
07-04-2007, 12:07 PM
#29
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Thickness is one factor; warping is another (I had brand new rotors and they came warped!); also, if they're drilled, closely examine the cracks between the holes. If the cracks stretch to other holes, change the rotors with OEM only. I've owned "knock-offs" and they never worked for me over time.
Don't turn them as they cannot be as dependable and predictable as new ones. It's just not worth the risk to you and your car if you get a major failure due to "short cuts."
Don't turn them as they cannot be as dependable and predictable as new ones. It's just not worth the risk to you and your car if you get a major failure due to "short cuts."
