I track my MCS every other month and I wanted to improve my brake fade resistance with new rotors. I bought a 4 corner DBA 4000 (slotted and drilled) set to replace my worn out stocks. Since installation, I've driven around 200 miles including a trip from Miami to Sebring International Raceway (168m).

I've run Hawk Blues and H10s for over a year on the stock Mini rotors and wanted to improve brake fade resistance. The problem with the DBA rotors in my application is that the drilled holes quickly filled with the pad material, preventing proper cooling which then caused overheating. Some holes were completely filled, looking as shiny as the rest of the rotor: the material had melted under heat stress and been smoothed over by the rest of the pad. After they cooled sufficiently, I pulled off the rim and used an allen wrench to clear the holes. I also found slight cracking on some of the drilled holes.

After my second session, when I pulled into the pits and stopped, they were so hot that the right pad stuck to the rotor. A few of the holes were filled again. Hoping there wasn't a master cylinder issue causing the sticking, I checked the calipers for fluid pressure (they were fine) then waited for them to cool before trying to see if they would come free and they did, without any problems. By the end of the day, I went through my HT10 front pads over 3 30m sessions, something I've never done with flat stock rotors before.

I know that with the amount of money I've dumped into my brakes over the past year with braided lines, multiple pad combinations and these rotors, I am getting close to a Wilwood kit, which is now out of reach for the time since I dumped all of that extra cash into this disappointing race weekend. Short of that, does anyone have some advice as to what route to take?

 

Maybe a good set of cryo treated rotors? That would help with the heat issue but as far as pad material buildup, I has no idea.

 

Might think about Carbotech pads and TSW Rotors. Both run very cool on track setup and no holes to fill with pad shavings. PM for more details for your type of events and driving style. http://www.autoxcooper.com/ctbrakes.html

 

Your problem with the drilled rotors is probably the reason why you hear so many people saying not to use drilled rotors on a track car. They look really nice going down the street and parked in the lot but on a track car where temps get astronomic stress cracks and filled holes are common. I think on the tire rack page it even has a caution clause on the drilled rotors that they are not intented to be used in a track situation. If you think that cooling is needed on rotor I think better money would be spent on brake cooling ducts and slotted rotors instead of drilled.

 

Your problem with the drilled rotors is probably the reason why you hear so many people saying not to use drilled rotors on a track car

I second this-By cross drilling you reduce the amount of heat the rotor can take. Brake duct work will help alot with your problem

 

Thanks all. I knew better, and almost bought the cryo'ed Powerslots, but was hoping for a better outcome. I picked form over function. They are real purty rotors after all. The rear rotors are fine since they contribute, what, only 20% of the braking power?

I went back to look at the DBA site for the explanation of their color ratings so I can see how hot the rotors were. The green paint melted away, the orange paint turned a beige, and the red paint was white (>1166˚F), most likely due to the cooling issues I mentioned above.

@03BRG, on ducting:

That is what one of the track teams told me to do: add ducts for the brakes. They do it to all of the Porsches they maintain. Another Mini owner also mentioned this duct kit, but I don't think I want to get that radical. Installation requires pulling the worthless fog lights and cutting through the wheel well. I'll probably replace the rotors with something more suitable to my needs.

Since posting I've been approached by vendors, but would appreciate any track junkies pad/rotor combination advice.

 

Way Motor Works makes beautiful brake ducts that replace the fog lights.

 

I had Zimmerman cross drilled rotors and they cracked after two track days. I switched with Power Slotted Rotors and the fronts started to show surface cracks after 4 months of street driving and 4 track days. I am moving back to standard rotors and adding in ducts to finish out the rest of the track season. With ducts I am sure the Power Slotted rotors will be fine but I am staying away from cross drilled from now on. I am moving to OEMs because they are so much cheaper and with the ducts I am hoping that they will stay cool enough not to crack. I think I am going with the Way duct kit at this point.

 

Everyone I've spoken to seems to agree that sticking with the stocks is the way to go. I'm seriously considering the duct kit though, but I'm taking a break over the hot summer down here in Florida and don't plan on tracking until September.

So much for this experience.

 

You simply need more material - larger and thicker rotors. The Wilwwod kit is the way to go for many reasons, but a larger rotor with an aluminum hat will help to absorb and remove heat quickly. In addition, better emchanical leverage will help reduce heat indirectly since you will not be required to really hammer a larger kit.

Brake ducts add to drag and can in some cases keep the brakes cooler than necessary. (Porsches are faster in a straight line) As an aside, the stock mini brakes with good pads at Lime Rock are fine, but become completely overwhelmed at the Glen. So you need to evaluate where you are driving before making a decision...you may find that you need a different pad/rotor setup for different tracks. I used different pads for sure.

Over heating brakes will also lead to bearing and outer CV joint failures, and, add to tire psi growth thru heat transfer.

Try to find a floating rotor that is stock size - aluminum hat. This should help and you can keep all of the stock brackets...

 

i've got the ducts and the 13" willwood kit. At VIR I still roast the fluid. I'm a late braker and i know it. I have to do what i can to make up for less hp. Even with the BBK i still go through 3 sets of rotors a year. I don't replace rotors for fun, i do it when the crack goes through the edge of the rotor, not when there are lots of micro-cracks.

pay to play

p.s. i did 40 track days in 07 and i'm looking at 30 for 08. that doesn't include work.

 

what is the width of the rotors? Thats a lot of rotors you go through! But you sure did a lot of track days. Are you monitoring brake temps using brake temp paint?

You might want to talk to TCE about your setup. THey are a Wilwood dealer. You may need to consider upgrading to another setup if you are cooking fluid and rotors.

Might also want to consider a bigger rear kit to help provide more braking leverage and ease the work on the front. I think Ireland Engineering and TCE have a kit for that.

 

Wow, really? Sticking with stock-sized rotors? IMHO, you'll quickly find the limit of the setup in Florida with high ambient temps (oh, and some fast tracks!). Brake ducts will help with longevity on the track, but will do little to reduce peak temps (as we just saw when we did our brake testing at Eagles Canyon - check out the 'Let's Talk Track Brakes' thread in the Tires, Wheels, Brakes forum here on NAM - https://www.northamericanmotoring.co...d.php?t=152015).

Depending on how much track work you do, a BBK is a solid investment if you do more than a few a year. Otherwise, you're going to be held to the limits of what you can achieve with the stock brakes...

 

3 sets of rotors in a year isn't terribly bad if you're doing 30+ DE's a year... That's a WHOLE lot of track work!

 

i have the TCE 13"x.81 kit. they do make one that's a bit thicker but for what i need i thought that was overboard. This last set of rotors i got i had cryo-treated (one of the advantages of living so close to the heart of NASCAR) and i saw very little difference in wear on the rotors. I'm going to RR in a two weeks and i'll bring new rotors with me to replace when the current ones give up. I can't do any upgrades for a while. i'm back in school full-time and my occasional instructing/coaching doesn't pay that well. I've thought about the rear upgrade but just not an option right now.

 

Sure is! Which is why I mentioned considering a different brake kit.



A thicker rotor (1.25") would be more heat resistant than a .81" rotor and would hold up better and longer (all else being equal). A different caliper might also have a build that better deals with heat (such as one that uses different pistons and such). Lots of good info in the thread on track brakes on this topic.

Ducting will definitely help longevity also.

 

the bigger rotors add lbs per corner. can't remember how many but i think it was around 5 each. I've got the ducts also. please check my gallery. i had them molded into the bumper. locks very stock.

 

True, depending on how big you go... Our BDM setup (11.75 x 1.25" rotor + hat) weighs about the same as the OEM rotors...

 

I will only use a plain rotor, and have thought about going to the brake ducts. A friend has just put them, and he finds that his pad life is getting better with them.

I have been using Hawk Blues for my track events, and I am curious what kind of luck or performance increase people are getting with their HT-10s. Why do you need to go to the HT-10s?

Sorry for the hijack.

 

try using a higher temp brake fluid. Project Mu has the highest dry temp brake fluid available or you can go Neo Synthetic Super Dot 610.

 

Is it just flat out insane to run stock OEM brakes at a track event or can I get by. Obviously this would be my first time hitting the track so I think I'll be limited to how hard I can actually drive the car...but are they good enough to even survive that? I might be going to NJ Motorsports park next Sunday but I dont know if my brakes will survive. They were fading on some long downhill runs up at the Dragon last weekend...mostly due to people riding their brakes in front of me I forgot to mention they also have about 30000 miles on them as well so they're already probably more than half worn.

Thanks and great thread with a lot of really good information!
Steve

 

They will probably start to fade after a couple laps or little more, depending on how hard you will be driving. I don't know the track but if it is full of twists that might work against you, long straights with hard braking at the end won't help you any either.

 

you will definely experience fade at thunderbolt and lightning. i glazed my carbotech bobcats at thunderbolt the first time i was there....i almost bailed on my 4th run (and probably should have) due to brake fade. my rotors were also perty darn worn! new rotos and carbotech xp8's totally fixed that problem! i have since gone with a dedicated set of track/street rotors and pads have fun! i personally prefer thunderbolt as it has more turns....but know other miniacs who prefer lightning as it is much easier to get the hang of.

 

yeah we're running Thunderbolt...looks like a really awesome track but I am really worried about my brakes. You think even with an instructor in the car and me being my first time, that I'll drive the car hard enough to toast them? Basically what I'm worried about is wearing out my brakes so bad to the point that I won't be able to SAFELY get home.

 

For the record, Carbotech Bobcat 1521 pads are NOT track pads.

Safety is the key issue before, during and after the track event. You take street/OEM pads the track they will fade or fail. If they fade, you miss out on the track experience, they fail you it may end your track day early and there are no refunds on track days.

Why not get the right pads for the right event, think of it as insurance for your Track Day, MINI and YOU. Insurance against the above issues or pads failing on the way home and/or wearing out early and finding out about it too late.

Pads and rotors are like tires and gas, part of the cost of doing track events and like tires, your pads and rotors are the 1st level of safety to protect yourself and your investment in your MINI, oh yea and any others that might be in your way when your street or OEM pads fail.

Safety 1st my Friends