DBA Rotor Comparison

[Hellmun]

Hawk HP+ are metallic and would be harsher on your rotors compared to a ceramic of similar bite so it's not necessarily a weak batch of rotors. I only ever went through 3 sets of DBA's with about...100 trackdays on the carbotechs/DS2500/DS3000? I think I was averaging about 3 sets of pads per rotor set and those were being changed due to cracking rather than thickness.

That said the carb's were twice as expensive which seems to be the theme for high bite, lower rotor destruction pads. Hawks have great bite and are cheap which is why I use them.

Just to clarify experience, a more expensive rotor should be made of better metal and should last longer, my stock rotor lasted 8 days before cracking, each DBA4000 lasted about 30. It will give nothing towards brake feel... Using the cheap econo rotors on my 11.75" wilwood kit was giving me 3 trackdays max. 1 day on the 11.00" kit which got replaced after that 1 day. I always manage to crack my rotors before they hit minimum thickness but I seem to be unusually hard on brakes.

[madjak]

This is all getting a bit off topic...

Hellmun... I think I'm pretty hard on brakes when I'm on the track but I think pad/rotor wear mostly depends on the pad choice and temp they get to more so than driver. The driver can push things to the limit by braking later and harder but only up to the point of tyre traction.

On my car, the DBA T2 paired with DS3000 pads were both shot after around 4 track events... I did some other sprints and autocrosses but I don't think these do that much damage. I would guess the T3s would last at least twice as long given the better metal but they are nearly twice as much as well. This was on the tiny NA6 sized rotors which were glowing at night.

The Wilwood 11.75" econo rotors are lasting well, however I'm now running DS1.11 silicon pads which are an endurance pad with a flat co-eff of friction and basically no fade. I don't think the rotors are reaching the same temps and so they aren't cracking or wearing as much. I would guess if I was running the DS3000 they would be already gone. I would highly recommend these pads to anyone doing mixed events as they work the same at any temp and have solved my braking problems on cold brakes. Bit of a hassle to get them to fit our calipers though.

At the moment, my rears (11.44" Wilwoods) are wearing quicker than the fronts with the exact same pad. This means they are actually working, and I'm guessing they are getting a lot hotter. Has anyone made brake ducts for the rear?

For anyone on the track, I really think ducting is a must, and choose pads based on wear level as well as stopping, otherwise replacing rotors is going to get expensive and tiresome.

[marcusus]

The cost to replace with just standard rotors was $70 for the front pair and $60 for the rear pair. Given the DBAs cost me $550 all round, it doesn't seem worthwhile going down that path again. Especially since I'm definitely not pushing the braking to the limit on the track (try as I might!).

I guess my main concern is just making sure that there isn't something funny going on with the car setup. If that type of rate of wear has been what others have experienced, then it is what it is.

[MattR]

A lot of standard type rotors these days are pretty soft, and are generally designed that way for modern cars to stop better with crappy low noise and low dust pads to meet OEM expectations and are now considered to be a consumable item, so when they cost $130 a set of four, that's cheap enough for me not to worry about how much the brake pads chew them up.

If you can get a better rotor when on special, then jump at that. The performance difference for a road car that sees some track time is bugger all.

The performance difference for a light weight car that sees track time only, is really bugger all in the scheme of things. Past race cars have used cheap rotors not a problem, just treated them as consumable, as they were cheaper than the pads I was using. Used to get maybe two sets of pads to a set of rotors, for plain vented, for slotted, one set of pads and change the rotors also.

Find what works for you, fits within the service requirements and budget you're prepared to pay and it's happy times out on the road and track.

Personally, I have slotted rotors front and rear on my NA6, because when I got them they were cheaper than normal rotors, and I run Hawk pads front and rear no problems on the road and with a few track days each year. I just flush fluid through every couple of track days, and before each day throw the car on some stands so I can do a nut and bolt check and make sure all is OK underneath and nothing will fall off.

Next set of rotors, if I still have the car, will be whatever is the cheapest at the time.

I think a few people get caught up and overthink what they want to achieve and how they want to achieve it. Me, I try to use the KISS principle, it has worked for me in most things for a long time.

[marcusus]

I'd quite happily keep getting the slotted ones if they had better longevity. Agree that I'll probably not get any noticeable difference between the slotted and cheapo rotors on the track, but the slotted ones sure do look better!

I daresay that if I end up going back to Hawk HP+, I could probably put my slotted rotors back on as they shouldn't require machining if it's the same pad. I just still can't believe that 30,000km on pads I didn't think were that aggressive can cactus them!

[MattR]

No need to machine the rotors for different pads, just give them a good going over with some 200 or so wet and dry to clean the old material off and then rebed them.

I can't remember the last time I have machined brake rotors if ever.

[marcusus]

Hmmm... Sounds like a much better option than turfing them. I'll check the thickness when I get them back, and perhaps do that for the next set of brake pads if the thickness is still good.

[project.r.racing]

I don't think there is any need for slotted rotors.. who needs good braking in the wet anyhow? I'm certainly not braking limited in the wet, it's definitely a traction limitation.

What do the slots of to do with the wet? The slots have nothing to do with water.

[madjak]

My understanding is:
1) the slots clean off the accumulated brake dust as well as give room for the pad to off-gas during a braking application.
2) They also help clear water off the rotor in very wet conditions probably only applies to street usage
3) They wear down pads quicker than non-slotted rotors.
4) They would be a smidgen lighter and slightly more prone to cracking.

Braking power vs non-slotted... I'm not sure there would be any noticable difference.

Edit: I'm not saying the water clearing would impact on braking performance in fact I'm arguing that it's not a factor. If there is that much water on the rotor that you need slots to clear it, then you've got no grip at the tyre anyway.

[Luke]

I gave up on Expensive DBA 4000's for my SE, with mainly track abuse. Standard NB8B brake setup.
$330 a pair up front from Race Brakes just wasn't doing anything for me with my pad choice and car use.
Cracked DBA 4000 6x6 Wiper Slot with 2 sets of Hawk Blues, and about a total of 12-13 track days. These pads were being eaten up by the slots and rotors likewise.
Cracked DBA 4000 T3 with 1 set of Carbotech XP10's with about 7 Trackdays, pads still good and little wear on rotors!!!. Pads and rotors were completely in-compatible with each other, plus Carbotech advises not to use slotted rotors with their pads, lesson learned.


The setup I have now is what I am most happy with.
Plain Protex Rotors. ($110 a pair shipped, thanks ebay)
Carbotech XP12 Pads.
Trackspeed 2 inch ducting to keep it all cool. I believe this is the most important part.
Up to at least 11 track days on them now and pads look like they will go another 2 rounds. Rotors have heat crazing. Will just throw rotors out with the pads at the price they cost.


Incidentally the worst rotors I have used were RDA Slotted and Dimpled on the rear with Hawk Blue's.
They just ripped each other apart whilst the rotors had slots, that was for about 4-5 track days. The wear slowed dramatically once the slots were gone, which also meant below minimum thickness but they only lasted 8 or so track days/one year on the rear!
I got the factory rotors machined and put them back on. I now run them with Carbotech XP10's. Much better combo.

[marcusus]

After the track day last weekend, I found that my braking was probably not quite as strong with the new setup versus the old. But given I changed both pads and rotors, it's hard to determine which one was causing it. I was still happy with the performance as the problem is still with the driver rather than the car

It might be worth just keeping the slotted rotors for one more round of usage before I just stick with whatever cheap rotors I can get and replace them when they die.

[StillIC]

...plus Carbotech advises not to use slotted rotors with their pads, lesson learned.

I don't think this is correct at all.

My evidence is that a) I run slotted DBAs and Carbotech and think they are the best combination of brakes I have ever used, and have had the same rotors and pads for a few years of motorsport now, b) Carbotech's brochure has a picture of slotted rotors on the cover, c) I have read their entire website and found no mention of slotted rotors not being compatible; they do however advise not to use cross drilled rotors due to susceptibility of cracking.

http://carbotechperformance.com/carbotechbrochure.pdf

However, Emilio at 949Racing, one of Carbotech's dealers, does not personally like slotted rotors and advises not to run them due to the fact that they are more susceptible to cracking, not because they are incompatible with the pads. I personally have found no difference with the few sets of rotors I have owned (slotted and plain), and found they all heat craze, but most wear out before they crack through. Although the Carbotechs are so kind to the rotors that they just might crack before wearing out, as wear is so slow.

[Tony]

I've previously had DBA 4000 T3 (Club Spec) rotors and Carbotech XP10 pads; in my setup and for my application, the combination was complete rubbish. As Luke suggested, rotor slot design and pad material were completely incompatible; I couldn't get rid of them both quick enough.

YMMV.

[Dan]

I've previously had DBA 4000 T3 (Club Spec) rotors and Carbotech XP10 pads; in my setup and for my application, the combination was complete rubbish. As Luke suggested, rotor slot design and pad material were completely incompatible; I couldn't get rid of them both quick enough.

YMMV.

You didn't really explain what the problem was so I assume it was wear rate.

I have had a bit of experience with Carbotech’s having run through a set of XP10’s, running XP8’s on the rear and just starting on my third set of XP12’s.

I have always run blank rotors on my MX5 so type of rotor has had nothing to do with it but one learning I had is that the need to do a proper bed-in like they suggest is no joke! My first set of XP12’s I did a half ass job of bedding the pads and ran through them in 5 track days which was less than I got out of my XP10’s with my second set of XP12’s getting 10 track days.

I don't see any reason to buy slotted rotors so I’m just using DBA blanks and am happy with them, they are cheap and seem to be holding up pretty well. I planned to replace them with the pads they are so cheap but we had a look at them when I replaced pads at 10 track days and based on the wear they should make it to the next pad replacement.

[Luke]

Tony had the exact same issue I had. We both had the same identical setup. SE, T3's, XP10's up front. I wasn't even using r-specs, only Kumho KU36.
The main issue was build up of pad material around the slots, causing high frequency vibrations under braking, then overheating due to the vibrations. I believe that's what caused mine to crack, as they were barely worn. The vibrations under brakes were so bad, you couldn't see out of the rear view mirror.


Back in in 2012 when I got in contact with Carbotech they told me this.
"It could be related to improper bedding, going over the temp limit of the pads or the rotor design."

After discussing with them:
Bedding in was done correctly. I had that even bluish haze over the whole rotor.
As for going over temp limit, maybe, but Hawk Blue's just worked and never faded with the older 6x6 design or standard factory plain rotors. Plus they have a lower temp limit, so I still today would say that the pad and rotor combo were not working well together.
Hawk Blue temp Range: 38°C - 650°C
Carbotech XP10 temp Range: 100°C - 800°C

Back in 2012 I did not know of anybody else who was running Carbotech pads for club track days or Supersprints so had few people to compare with at the time.
Hellmun used XP10's and XP12's without an issue on the 6x6 design with NN8B brakes and pushed the brakes pretty hard over their life without any vibration issues.
The only other guy with a similar setup at the time was Russ with his NC, T3's and XP10's. No issues at all for him.

What happened through a track day was odd with the T3's and XP10's on NB8B rotors. Turn up with bedded in pads/rotors. It would be OK for 2 sessions, but you could see the transfer layer getting high spots around the slots and low spots where you see shiny rotor metal between slots on the surface. It would then just get worse and start the vibrating. Hence why Tony and I both gave up on that setup as it was literally vibrating our cars apart.


Just saying that Rotor and Pad combo can be critical, from my experience so far.
I could fork out the extra money and buy the plain DBA 4000's but with the amount they cost I would rather just buy new Protex rotors with every set of pads.
Less ugly rust that way to.
From what I have seen Emilio at 949 is pretty much on the money for using Carbotech pads with plain rotors, and it was him not Carbotech that suggests this as you pointed out.