rotors

[sickmint79]

can these rotors be turned, or are they done? do you guys recommend turning them anyway? does this mean the pad i had was just a crappy street one?

miata rotors (actually for a vw corrado) with a wilwood bbk after 3 track sessions at autobahn south.

http://www.developer10.com/users/mike/scripts/rotors1.jpg

http://www.developer10.com/users/mike/scripts/rotors2.jpg

[MPIGP - Phillip Gordon]

Sorry I can't really tell for sure from the pictures....are the lines actual grooves in the rotors? If they are, I wouldn't recommend turning them especially for track use. If the lines are just score marks, it may be particles of the brake pad stuck to the rotors. This will cause a vibration similar to warped/grooved rotors but one session of bringing the brakes up to temp and doing some really smooth hard braking will clean that off.

If they are really grooved after only 3 sessions, a possible cause could be from braking too hard too soon with agressive pads similar to say a Hawk Blue. I know for a fact Hawk Blues can cut into rotors when not up to temp.

[MPIGP - Phillip Gordon]

Thought I should mention, you may want to try the cryogenic treament on your next set of rotors and brake pads. They will last longer.

[Martin Lenick]

I know for a fact Hawk Blues can cut into rotors when not up to temp.
When which is not up to temp? The pads, or the rotors?

Aside from calcium carbonate, there are few compounds, especially metals, that get harder with temperature. If neither of these are composed of some of those few, then the pads coming "up to temp" more so than the rotors would give them a relatively lower Brinell rating and thus less ability to "scratch" (using Brinell's original terminology) the rotor. However, if the rotor acquires and retains more heat than the pads, it will be more susceptible to scratching from the pads.

[Rick]

Who is this Brinell guy? Does he race with us? :sly:

[Martin Lenick]

“I know for a fact” that if you install a flux-capacitor and a 1.2 jigawatt-capable battery, then wait until the moment you take the checkered-flag and enter the gap between you and the leader and hit “BACK” you’ll win the race, provided you're still on the lead lap and can achieve 88mph before the line.

Johan August Brinell, developer of the Brinell Hardness Test, "I know for a fact" invented the flux-capacitor. In a trip to the past Dr. Emmett Lathrop "Doc" Brown stole his idea, carried it to the future, and... McFly!!!

[MPIGP - Phillip Gordon]

When which is not up to temp? The pads, or the rotors?

Martin

Not sure about how your brakes work but mine tend to heat up both the pads and the rotors at the same time when I step on the middle pedal in my car. When I said up to temp I meant both pads and rotors.

However, I get your point so let me rephrase my 'I know for a fact' statement. What I should have said was, from my personal experience with Hawk Blues on Coleman custom rotors, (sorry I don't know the Brinell rating) when the brakes (rotors and pads) were not up to temp, they cut into the rotors.

[sickmint79]

i think the lines are just pad deposits, i was more interested in the opinion of all that pad material stuck in the slots. i think they were just crappy pads that melted into there; don't know what we got on the car when we bought it.

we have since purchased some racing beat slotted rotors and some aggressive street pads and a set of track pads.

regarding rotors, is there any need for slots still? the guy from tirerack said pads do still gas. although i have heard otherwise elsewhere. if no need, why do i find 2-piece rotors always slotted, why don't they make them with blanks? was having a hard time finding any for this car (miata) at least.

[Rick]

i was more interested in the opinion of all that pad material stuck in the slots. i think they were just crappy pads that melted into there; don't know what we got on the car when we bought it.

I had StopTech brakes and rotors with slots on my M3 and I never really had that kind of build up. On the other hand, my Lotus has drilled rotors and they're clogged with brake dust. I think it has to do with the pads. I ran Pagid Orange on my M3. On the Lotus, I currently have Porterfield R4S (Street). Prior to that I had the OEM pads. I asked someone at the track about this and they said it's normal.

regarding rotors, is there any need for slots still? the guy from tirerack said pads do still gas.

I've think that slots are better than drilled because they add extra bite, help to dissipate gas just like drilled rotors. The advantage is that they are less likely to crack.

[sickmint79]

i've never considered x-drilled, i'm still between whether slotted or solid is "best" - and under the impression that if there's no gas, solid are the best. and i have heard modern pads don't gas - but i still see all these "racing" type rotors slotted.

[MPIGP - Phillip Gordon]

i've never considered x-drilled, i'm still between whether slotted or solid is "best" - and under the impression that if there's no gas, solid are the best. and i have heard modern pads don't gas - but i still see all these "racing" type rotors slotted.

I ran solid rotors on my BMW with the BBK. A few people that I've spoken with say they like the slotted because it 'cleans' the pads and channel out dust. Personally I think the more rotor surface area such as in the solids, the better the stopping power.

[Hornswoggler]

Rick, I didn't know you had an M3... do tell more!!

[Rick]

Rick, I didn't know you had an M3... do tell more!!

Had a 2005 M3 ZCP and sold it and bought an Exige S.

[Hornswoggler]

Can't blame ya there! I'm sure the exige is much more involving...