Brake rotor? which ones?

[jaywish]

I usually use the Centric Premium Rotors or equivalent which I think of as Motorcraft, regular line Rabestos etc.

Occasionally I think about going to a sloted/drilled rotor or the high carbon rotors.

Have never tried anything beyond stock grade disks.

I see Rock Auto usually has "Power Stop" drilled and slotted for cheap. The fact that they are cheap makes me wonder if it is a get what you pay for thing and they would be a waste of money.

Anybody use the premium type rotors?

Jay

[Mainemantom]

I just bought and installed power stops from Rock Auto for the Subaru. I am hoping they will last.

[Lincolnmania]

drilled rotors crack, i have replaced many sets.

[johnunit]

yeah, my research has me somewhat regretting cross drilled rotors on my Mazda.

If you want performance, slotted will help. But given my crown vic is stock brakes and has held up to autocross and stops from 80+mph without any fade ever, even with way more tire grip than stock, I'm not sure it matters.


FWIW I'm running whatever Raybestos' top line is on the vic and am very happy.

[Kodachrome Wolf]

I've been running NAPA's Premium grade rotors and pads up front. Was using Motorcraft originally. Both have performed well and the Motorcraft stuff lasted a good bit before I replaced it.

[GM_Guy]

Drilled rotors remove mass from the disc. Less mass = less heat capacity. Less heat capacity = you get the idea.

Alex.

[IPreferDIY]

My big concern with drilled and slotted stuff is that the brake pads presumably wear out quicker. And isn't the drilled and slotted stuff more for racing applications anyway?

[sly]

because racecar yo!

slots help remove dust buildup and water from the pads. holes... "help cool the pads" but it's marketing BS. They also help remove dust and crap from the pad surface, but slots are better at it. They do wear the pads more than flat rotors since there's edges to deal with for the pads. I'd just get regular quality rotors and EBC yellow stuff brakes if available. Those supposedly grab great, though they're a bit pricey for my liking.

[gadget73]

If the rotors are designed specifically for drilling and whatnot, its not so bad. The problem is that most drilled rotors are simply standard (or substandard in some cases) rotors with holes poked in them. Unless this is done very specifically, the holes usually end up into the support / cooling fins in the middle and you end up with weaker rotors, especially if the stresses from drilling are not relieved. The heat buildup from machining operations will tend to screw with stuff. Same thing with the slotting. Cut too much out in the wrong place and the rotor is more prone to deformation. You're honestly better off with a good quality rotor rather than some wanky nonsense. I've seen a couple of the rotors Scott pulled off, and they were often seriously warped and in some cases they had cracks forming around the holes.

I've had the same set of rotors on the Towncar for years now. I think they might be Wagners, but I can't really swear to that. Its been 8 years or something, with the same brake pads actually. I've been pretty happy with those Performance Friction pads. Some 60k later and they're not worn out yet, though they are probably under 50% pad life at this point and starting to get a little more messy. Still stops on a dime and gives change though.

Last set of Bendix rotors I tried on the truck were produced in China and the studs were not in the right places. I think everything else I've gotten in the last 7 or 8 years have been Duralast Gold and I've had no trouble out of it.

[jaywish]

I just had a nice discussion with a very knowledgeable technician who designs many of the Centric products on this issue. He asked me a some questions, Where do you live, What do they use on the roads in winter and Does the car sit or get driven every day?

Basically he indicated that rust is the main failure problem with drilled and slotted rotors, and rotors in general. Particularly in areas that use the brine concoctions as opposed to just rocksalt. The rust does not get cleared from the holes and slots as the main surface of the rotor does. So his advise to me was do not use drilled and slotted on a winter driver in my area.

This advice make sense and did not make them any expensive rotor sales. Take that in conjunction with Gadget's analysis and the weak points rust out causing failures.

Holes and slots are probably great in areas that don't have salt issues or for a 'nice day' driver. Given that they are a quality product to start with.

As far as solid rotors and rust he indicated that many of the problems commonly attributed to warping are actually due to corrosion. They study rotors under a microscope and have found that if spots on the rotors get a little deeper rust then some other spots you get the sensation of a warped rotor. This is not necessarily obvious with a casual look at the rotor as the rust is swept away by the pads in normal driving, but micro pits are left behind. So if an area of the rotor has more micro pits then another the pad friction will vary as the rotor spins giving a pulsing feeling often attributed to warping.

[gadget73]

I've read a similar theory that says warped rotors are actually a case of brake material "welded" to the steel, creating a high spot. I don't really think that makes sense because the pad running against the rotor should grind that down pretty rapidly, but low spots from corrosion I could believe. Perhaps the two theories together explain it, over-heated pad material deposits on the rotor and causes those small pits, not a high spot.

Salt causing corrosion that causes cracking I'd also believe. Having the salt get into the holes is also entirely plausible. Salt does fairly horrible things to metal.

[jaywish]

I had that conversation a few years ago with the same fellow. The heat can change the structure of the steel. He said it occurs right under the pad after an emergency stop. The rest of the rotor cools quicker than the spot under the pad. It is there that material can be deposited. The deposit and or the change in the structure of the steel causes spots of different friction giving that pulsing feeling.

The steel is harder than the pad material which is why it does not wear off the high spots so easily.

I

[turbo2256b]

Go with raybestos PI ROTORS AND PADS. My first set pads went over 100K still on the rotors in great shape never been turned 5 years after replacing the first set

[P72Ford]

I always order Centric Premium rotors from RockAuto. They are great quality, and the hats and cooling veins are coated so they do not become an eye sore.

I did a lot of research on drilled/ slotted rotors back when I had my Mustang. The main take away that was that they are primarily a cosmetic thing. Read up on some road-racing/ super car forums (with folks who actually race the cars). Nothing but complaints.

I used some more aggressive Hawk pads on my Mustang, and they were not appropriate for street use. They dusted 10 times worse than OEM pads, and they squeeled until they reached temperature, which never occurred with normal street driving.

I believe that most of the brake parts from Auto Zone and Advanced are nothing but garbage. RA offers Centric, Wagner, Raybestos etc, and I don't think you can go wrong with any of their premium lines. Even with shipping, they're usually cheaper than the local box stores in house brands, and they outlast them.