GPz11
Reader
8/25/18 7:17 a.m.
So I need to get a new set of rotors for my XR4Ti since it turns out the Ebay rotors just aren't cutting it on the track, who knew??
I've got Mustang Cobra front brakes with EBC Yellowstuff pads and during my last SCCA track night I started having some bad brake shimmy / shudder going on. I'd back off a little bit and it would go away.
While surfing on TireRack, I noticed they offered some of the rotors with cyro treatment. Has anyone noticed a real world improvement with the treatment?
Work the extra bucks?
They seemed to be a big push in advertising of these then nothing. I never heard anyone with real life experience with them comment one way or another about it. It would be interesting to here more about this as it has been around for a while now.
bcp2011
New Reader
8/25/18 8:30 a.m.
In reply to GPz11 :
The shimmy... new pads and new rotors? I’ve found that some race pads really don’t play well with others (carbotech being one of them) so you need to turn the rotors to remove pad deposit before putting another pad on. Otherwise you get pretty severe shuddering. Learned this at road America...
GPz11
Reader
8/25/18 8:50 a.m.
New pads and old rotors. The pads had a couple hundred street miles on them and one track night before this one.
I was going a lot harder this past night since the car was running cooler with the new Trackspec hood louver.
Hard to say. We used Cryo treated rotors on our S2K for the last brake change. It's an autox/track day car and we run very aggressive Hawk HPS pads. After almost 2 years use, the front rotors show some wear but still look fairly smooth. The backs look more grooved, but I suspect that's because the back brakes run cooler, letting the HPS pads chew. I haven't had any problems with rotor warpage or cracking and "I think" the braking is a bit more consistent than with the old OEM rotors (also on HPS's)
Years ago, I was a research fellow in a biopreservation group at Harvard Med School. So, I have some experience super-cooling stuff with liquid nitrogen.
I tried "cryo treating" my Spyderco Delica folder with some nitrogen that was about to get discarded. It made the blade very hard and brittle, to the point where it stopped being very useful as a knife: chips easily and is very difficult to sharpen.
You can think of cryo treatment as analogous to quenching a heated piece of steel. Good for improving hardness. For a brake rotor, that may translate to less wear. Then again, you rely on friction between the pad and rotor to slow you down. I'm not sure whether a harder, glassier surface is actually a good thing in that case.
bcp2011
New Reader
8/25/18 2:19 p.m.
GPz11 said:
New pads and old rotors. The pads had a couple hundred street miles on them and one track night before this one.
I was going a lot harder this past night since the car was running cooler with the new Trackspec hood louver.
If you didn’t turn the rotors before putting on the new pads it’s worth it to see if that works.
I got a pair of cryo-treated and slotted rotors from Tire Rack when I did my "big brake" swap (from Fairmont 10" rotors to '93 Mustang 11"). They were $110 each. After a couple of track days, I noticed an lot of vibration under braking. Investigation revealed a crack in the outer face of one rotor, nowhere near a slot. I bought some $35 NAPA rotors, and haven't had a problem since. That was 3 or so years ago. I use Performance Friction pads for street and track, and I don't brake as effectively as I should.
What did F1 do when they were still using metal disc brakes ?
or Indycars , Nascar etc
Cactus
Reader
8/25/18 4:10 p.m.
I know cryotreatment is necessary to complete full heat treatment of some slightly exotic (stainless) alloys. I'm not sure what exactly it does to cast iron rotors, given you're (probably) going to heat them up above 1000 degrees during use.
I use cheap Power Stop slotted rotors I get from RockAuto and have no problems.
I use 280zx brakes, the OEM rotors had been on the car forever. It's a long story but I started having issues with brake chatter and went so far as having my machinist buddy turn both rotors to within a thousandth. When I put them back on the car they went about 8 laps before the chatter returned. I then used some parts store brand those went maybe 5 laps before they started actin up. The rotors had almost no perceptible run-out yet once the brakes warmed up they rattle your teeth out. I even had made sure to loving bed new pads in.
When I put the Power Stop rotors on the car and all the problems disappeared; note I'm not advocating a particular brand I'm just saying get a decent quality set on the car and don't worry about the Cryogenicly treated ones.
Tom1200 said:
I use cheap Power Stop slotted rotors I get from RockAuto and have no problems.
I use 280zx brakes, the OEM rotors had been on the car forever. It's a long story but I started having issues with brake chatter and went so far as having my machinist buddy turn both rotors to within a thousandth. When I put them back on the car they went about 8 laps before the chatter returned. I then used some parts store brand those went maybe 5 laps before they started actin up. The rotors had almost no perceptible run-out yet once the brakes warmed up they rattle your teeth out. I even had made sure to loving bed new pads in.
When I put the Power Stop rotors on the car and all the problems disappeared; note I'm not advocating a particular brand I'm just saying get a decent quality set on the car and don't worry about the Cryogenicly treated ones.
My experience with brake vibration has been more about hard or soft spots than runout. Once I determined that I could ruin a set of rotors overnight if certain conditions were met, not parking a vehicle with hot brakes became an obsession to the level of a religion with me. Once I even intentionally ruined rotors for my friend's little sister because the dealership told her that they "weren't bad enough to worry about (little girl)", just by doing a few hard stops, and immediately parking it for 12 hours.
snailmont5oh said:
Tom1200 said:
I use cheap Power Stop slotted rotors I get from RockAuto and have no problems.
I use 280zx brakes, the OEM rotors had been on the car forever. It's a long story but I started having issues with brake chatter and went so far as having my machinist buddy turn both rotors to within a thousandth. When I put them back on the car they went about 8 laps before the chatter returned. I then used some parts store brand those went maybe 5 laps before they started actin up. The rotors had almost no perceptible run-out yet once the brakes warmed up they rattle your teeth out. I even had made sure to loving bed new pads in.
When I put the Power Stop rotors on the car and all the problems disappeared; note I'm not advocating a particular brand I'm just saying get a decent quality set on the car and don't worry about the Cryogenicly treated ones.
My experience with brake vibration has been more about hard or soft spots than runout. Once I determined that I could ruin a set of rotors overnight if certain conditions were met, not parking a vehicle with hot brakes became an obsession to the level of a religion with me. Once I even intentionally ruined rotors for my friend's little sister because the dealership told her that they "weren't bad enough to worry about (little girl)", just by doing a few hard stops, and immediately parking it for 12 hours.
Wow, thanks. This is spy level E36 M3.
devina
Reader
8/26/18 7:44 p.m.
I haven't run the cyro treated rotors since I am not sure they will help anything. I have had good luck with centric premium rotors on my ITA Integra running hawk dtc60 pads.
I have never heard good things about ebc pads on track and would start with some more track ready pads and decent rotors.
I would also never turn rotors on a car headed for the track..removes too much thermal mass from the system. If swapping to different brand pads, try a little scotch bright pad action to remove the old pad material from the rotors.
GPz11
Reader
8/27/18 11:11 a.m.
Thanks everyone, I'm going to get some of the Centric High Carbon plain rotors and trying to figure out which set of Hawk pads to go with.
@snailmont5oh..........yes that is what is was trying to say in my in my usual round about way. My issue was about pick up as well. I did have one set that had what I would call hard spots, they were super cheap and I got what I paid for.
For the record I use semi bargain brand Beck Arnley pads but give I'm using brakes from a 2800lb car on my 1600lb car.
New pads and new rotors and then follow a proper "bedding-in" procedure. You can't change pads and use old rotors whic had different make/compound pads used on them. When hot, they don't play nice together.
There is a HUGE difference between brakes that were bedded-in correctly and ones just installed and used. HUGE!!!!
I doubt the pads are at fault, I've run EBC Yellowstuffs for years on my AE92 and I haven't had any shuddering/warpage-like issues, other than the fairly rapid rotor consumption (getting maybe 2-3 sets of pads to 1 set of rotors), they haven't given me any trouble. I've been using those with Centric plain rotors.
EBC got a bad reputation early on from having an issue where the pad material would shear off of the backing plate, but they'd solved that within a couple of years and it's not deserved anymore. If you're switching to Hawks, don't use HP+, people make the mistake of thinking that they could be a good dual-use pad but they're not - they're a highly specialized autocross pad that's bad at everything else.
I just buy cheap new rotors every time I put pads on and use good pads (carbotech, mostly). Never had an issue so I don't understand why people spend lots of money on expensive rotors. It might make a difference on heavy high power cars, but I haven't seen any issues with cheap chinese rotors.
Well, FWIW, since I asked the question, I've switched to Wilwood 6 pots, 12.9" rotors and Hawk pads.
Will we see you this year at TNiA in Blackhawk?
I caught up /w you at the end of a session last year and we chatted for a while.
For sure, I'm hoping to get out more this year.