What brand of rotors should I get?

#1

I am trying to get some information before I start purchasing rotors.
I know there are cheap generic brands to stay away from but I do not know which ones.
I also know of ATE.
What brand rotors should I be purchasing for my car?

#2

I have heard three popular opinions. Some guys like the more expensive ~$70 blanks, some guys (me) like the $15 blanks, and Fish likes the lifetime warranty Duralast rotors from Autozone so you can get them replaced. I replace my rotors everytime I replace the pads, and I have had no issues.

#3

Full season and still on the crappy $15 rotors. No warpage, but horrible pad taper. Don’t plan on replacing them until they are past the thickness replacement spec, or they warp/crack.

#4

I get the cheap china rotors. Run them until they crack, which is about a full season for the fronts. Never replaced the rears in the 2 years I’ve owned the car.

#5

After the last race i have a lot of surface cracks that don’t run all the way to the edge. I want to know how much is acceptable. I’m using ATE premium slot rotors with no cooling.

#6

I think they have to catch a finger nail to worry about it.

#7

I know it is not really comparable, but we used brand new cheap rotors on a chump car 24 hr race and had a bad cracked rotor after about 6 hrs. They definitely didn’t hold up.

I’ve heard interesting arguments recently that cooling the brakes might be a bad thing in our cars for rotor life. I’ll post that up as a topic and see what kind of feedback I get.

Jason

#8

I use the stock brake cooling. Too cheap for cooling ducts. No fading issues, except when the pads taper really bad.

#9

Hi All,
Thank you for your input.
I decided to go with the generic white box because of the feedback here.
I now need to post a limited slip question.

#10

I started the season with the white box rotors. Ran two sessions at Lime Rock, ran a practice, qualifying and a race at NJMP and they finally cracked at CMP after 2 DE sessions and a practice session. I had a gift certificate for Turner Motorsports so I splurged on some Powerslot rotors for $150. They are holding up pretty well after a weekend at VIR and 6 sessions at NJMP. Now, if I didn’t have the free money, I would’ve just bought another set of the white box rotors and kept a 2nd set as a spare. If these last a long time, I may have to stick with them. At a $150 a pair, they are still $30 cheaper than just one of the rotors I used to run on my 944. :blink:

#11

please show the thread where someone says cooling is bad for rotor life. that is completely counter-intuitive to everything anyone in the engineering world has told me…

As well, i have seen rotor life with and without cooling. they last noticeably longer with cooling

#12

I’ll have to dig around for it. It was on another forum. Not saying I agree but it made just enough sense to make me question.

The idea was that the factory set up didn’t get too hot the way it was designed. But with a better cooling set up the rotors are heating up and cooling down to a larger degree and more often which they are saying would cause the cracking sooner.

It hurts my brain to think about it this much but that was the just of it. I’ll search around for the thread but in the meantime I’ll let some smart people here duke it out;)

Jason

#13

Just don’t make it too complicated. Your pads have a heat range. If the stock ducts can’t cool the rotors to have your pads stay within the heat range, you need bigger ones. However at long straight tracks you need to be slightly concerned about overcooling, which would make for a hairy entrace to some corners at the end of long straights.

I’ve seen people here run from Hawk blues to DTC 70’s. Big heat range difference. Blues are only good to 900F, DTC 70’s are good to 1,600.

Unless you have heat tape or paint to determine how hot they are getting, you are guessing. The good news is that fade usually shows up a lot better to a driver compared to lack of heat in the brakes and 0 braking force (that’s f’in scary btw).

#14

I put OP rotors on and they were cracked after one race.

#15

Some of the Aussies guys have switched over to the DBA 4000 Series that was made up for us about 18 months ago. Bigger dollars (AUD180/rotor approx USD165 less tax) but much longer life, only pair I know that has worn out did well over the equivalent of a season before requiring replacement.

That was on PFC06 pads, will be looking to see of PFC08 is kinder on the rotors again.

I’d find a solution that works for you. It doesn’t make financial sense to turn cheap rotors, just use them and lose them. Spend a little bit more for longer life, but try to make sure the slots (if you run them) don’t go all the way to the edge.

#16

Here is part of the scoop on rotors. If I can do this in a few short paragraphs… !!

First you analyze what they are and how they work - (and what you a racer can choose between)

The rules loosely say you must use an OEM rotor. Or one that is a LOT LIKE OEM. ouch. So we analyze the OEM rotors - and all the OE copies - the good and the bad.

First we must understand a few basic principles. Since we cannot grossly change the rotor shape (no curved vane 15" 2 piece rotors etc) then the primary performance criteria are overall weight (and to a lesser extent where the weight is) and the material.

Let’s start with material. That’s easy. OEM gray iron is much better than chinese bullshit gray iron. That should be obvious. BMW paid a lot more money/attention to rotor material than Manny, Moe and Jack the Pep Boys do. And gray iron constitution affects friction, heat transfer, heat capacity, and other super complicated engineering terms. That means it affects the SYSTEM - not just the rotor. So the money saved may be spent elsewhere in pads/fluid so the savings may not be as good as you think they are. The real question is HOW MUCH WORSE are these cheap shit rotors and WHAT DOES IT COST ME?

Now move to DESIGN. China may be good/bad in this. Do you think they intentionally cut rotor mass to save money on a $2 part (marked up 5 times to AutoZone) that has to get shipped to the evil USA. Nah…they would NOT do that… :). Of course they do. They use cheaper tooling methods that are not like OEM and ‘shave a lil’ here and there. Cliff notes! You can SAVE a pound - and have hotter pads/fluid - and a shorter life - and perhaps less consistent performance. Again the question is how much. If the rotor does not cause pad or fluid fade ( or any other braking malady) and cracks as I cross the finish line… it was PERFECT.

And lastly cooling. The iron in the rotor is GREAT at holding and moving heat - but AWFUL at getting real hot/real cold or even too hot or unevenly hot. Supply air to the entrance to the cooling vanes and you will moderate brake temps and see improvement in a stressed brake system.