Drilled rotors?
Are coil-overs worth it?
- Thread starter ERre23
- Start date
BenD said:
I agree brakes when road racing are a major concern with our cars. The most winning brake kit currently is the ones sold by Stoptech which is a 4-piston configuration. Drilled rotors on the track are a waste and dangerous. Rotors were originally drilled to allow gases created by the pads during braking to escape and not build-up under the pads. Current pads don't have this problem and using drilled rotors is not necessary and decreases the surface working area of the pad decreasing efficiency. Drilled rotors are highly proned to cracking and warping.
Wow! It's amazing how much force is created in racing situations.BenD said:
Are the 00R calipers a fixed caliper design? I'm interested as a street upgrade.BenD said:
iismet said:
Yes they are a fixed caliper with 4 pistons. I have them on my car. The pads they come with suck replace them if you order the kit.
toofast4u said:
Brian,
I have been looking for documented 60-0 stopping distances for the 00R but have not been able to find them. Do you know what they are? Did you see a $1000.00 improvement with the 00R calipers?
iismet said:
Never mind. Plenty of info at Cobra R forum.
Subsribing, holy shit this is a great learning thread!
Brakes on the track
toofast4u
I have to disagree with your position on drilled and slotted rotors. However, if you intend to run multiple races with the same rotors, then yes it may not be the wisest decision. As I mentioned in my post rotors are an expendable item and must be carefully inspected after and during the event.
Ferrari and Porsche both use them to on their race cars as well as Mercedes on their SL65 AMG, their SL600 Twin Turbo and on the 240 MPH McLaren SL. Ferrari has drilled and slotted rotors on the new F430 which will be some stiff competition for me next season. Why? because rotors grow at a dissimilar rate inside and outside of the rotor. It can be as much as 100 degrees or more difference between the two sides. A fully vented rotor allows the expansion to happen without causing as much warpage, that's why you find them on the expensive race cars that I mentioned. Do they often show heat fatigue cracks, absolutely. That's why you can't just put them on and forget about it, but they are much more effective and are necessary in my book. ALSO ALL RACE CARS ARE OUTFITTED WITH FIXED CALIPER DESIGN, stiffened across the caliper to prevent flexing. The Baer 6 piston are brakes of that caliber. Mass PRODUCTION CARS ARE NEARLY ALWAYS OUTFITTED WITH THE FLOATING DESIGN..IT'S CHEAPER! Including our Cobras' and they are simply worthless for Road Racing!
I wouldn't recommend that you use them for fear of cracking.
As for brake pads only dedicated racing pads that bare the discription "Pre-burnished" or "Race ready" are worthy for the track, NOT THE STREET! The bonding agent can withstand up to 1400 degrees F so outgassing doesn't become a problem. When that happens you immediately lose friction, I know, it happened to me last season trying to keep up with the Ferrari's in the corners.
Hope this sheds a little light on the subject for you.
toofast4u
I have to disagree with your position on drilled and slotted rotors. However, if you intend to run multiple races with the same rotors, then yes it may not be the wisest decision. As I mentioned in my post rotors are an expendable item and must be carefully inspected after and during the event.
Ferrari and Porsche both use them to on their race cars as well as Mercedes on their SL65 AMG, their SL600 Twin Turbo and on the 240 MPH McLaren SL. Ferrari has drilled and slotted rotors on the new F430 which will be some stiff competition for me next season. Why? because rotors grow at a dissimilar rate inside and outside of the rotor. It can be as much as 100 degrees or more difference between the two sides. A fully vented rotor allows the expansion to happen without causing as much warpage, that's why you find them on the expensive race cars that I mentioned. Do they often show heat fatigue cracks, absolutely. That's why you can't just put them on and forget about it, but they are much more effective and are necessary in my book. ALSO ALL RACE CARS ARE OUTFITTED WITH FIXED CALIPER DESIGN, stiffened across the caliper to prevent flexing. The Baer 6 piston are brakes of that caliber. Mass PRODUCTION CARS ARE NEARLY ALWAYS OUTFITTED WITH THE FLOATING DESIGN..IT'S CHEAPER! Including our Cobras' and they are simply worthless for Road Racing!
I wouldn't recommend that you use them for fear of cracking.
As for brake pads only dedicated racing pads that bare the discription "Pre-burnished" or "Race ready" are worthy for the track, NOT THE STREET! The bonding agent can withstand up to 1400 degrees F so outgassing doesn't become a problem. When that happens you immediately lose friction, I know, it happened to me last season trying to keep up with the Ferrari's in the corners.
Hope this sheds a little light on the subject for you.
not sure which races you're going to, but you wont find too many drilled rotors at an actual pro race. if the rules allow it, a carbon rotor is order of the day.
also note that bend races in some sort of unlimited class (sounds more like open track to me). what brakes are legal for your class is determined by the rules for whomever you run with. aside from the pad, the brakes usually arent up to the racer.
also note that bend races in some sort of unlimited class (sounds more like open track to me). what brakes are legal for your class is determined by the rules for whomever you run with. aside from the pad, the brakes usually arent up to the racer.
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Ben,
Have you ever checked out corner-carvers? There have been several posts about drilled rotors. IMHO you might want to check it out.
Have you ever checked out corner-carvers? There have been several posts about drilled rotors. IMHO you might want to check it out.
Once again about drilled rotors
Do they eventually develope stress cracks radiating out from the drilled holes? The answer to that question is MOST DEFINITELY they do given enough time and severity of use.
The only drilled rotors that are more resistant to developing stress cracks radiating out from the the drilled holes are the CERAMIC CARBON type rotors. They are enormously expensive, too much for my taste.
Once again! Drilled and slotted rotors dissipate the heat more efficiently and present less warpage. They have to be inspected frequently and changed when stress cracks start to appear. Tires fall in to the same category. They too have to be changed when worn down or show fatigue. These are BOTH EXPENDABLE parts of your car when racing. I am budgeted for that eventuality in both cases.
This should lay to rest the controversy, opinions, expertise and innuendos concerning drilled rotors.
As a note of interest to those of you that seem to have difficulty understanding this. Baer Brake Company, as a rule DO NOT RECOMMEND using drilled rotors in a Road Racing application. Why do you suppose that is? Because the average week end warrior has a habit for what ever reason, be it economic or otherwise, of leaving them on as a permanent fixture and secondly really not paying much attention to condition thereafter, no matter what the use.
You have to literally inspect them closely, often with a manifying glass that reveal the beginning of stress or heat fatigue. Or don't use them...period!!!
But no matter how you want to criticize it, twist, rationalize, opinionate, harp, hype, or impress...DRILLED ROTORS ARE MORE EFFICIENT.
Do they eventually develope stress cracks radiating out from the drilled holes? The answer to that question is MOST DEFINITELY they do given enough time and severity of use.
The only drilled rotors that are more resistant to developing stress cracks radiating out from the the drilled holes are the CERAMIC CARBON type rotors. They are enormously expensive, too much for my taste.
Once again! Drilled and slotted rotors dissipate the heat more efficiently and present less warpage. They have to be inspected frequently and changed when stress cracks start to appear. Tires fall in to the same category. They too have to be changed when worn down or show fatigue. These are BOTH EXPENDABLE parts of your car when racing. I am budgeted for that eventuality in both cases.
This should lay to rest the controversy, opinions, expertise and innuendos concerning drilled rotors.
As a note of interest to those of you that seem to have difficulty understanding this. Baer Brake Company, as a rule DO NOT RECOMMEND using drilled rotors in a Road Racing application. Why do you suppose that is? Because the average week end warrior has a habit for what ever reason, be it economic or otherwise, of leaving them on as a permanent fixture and secondly really not paying much attention to condition thereafter, no matter what the use.
You have to literally inspect them closely, often with a manifying glass that reveal the beginning of stress or heat fatigue. Or don't use them...period!!!
But no matter how you want to criticize it, twist, rationalize, opinionate, harp, hype, or impress...DRILLED ROTORS ARE MORE EFFICIENT.
:thumbsup: :read:Sailing2Smth said:
MidLifeC said:
Kind of a weak argument, mostly concerned with bling. Ben, on the other hand, argues very well from a racing/maintenance, perspective.
toofast4u said:
I read in another of your posts you were going to investigate swapping your front PBRs to the rear of the car. Was this possible?
BenD said:
I would be interested in tech to back up your statements rather than opinion. Your comments seem to throw mud in the eye of statements like this:
DRILLED VS SLOTTED ROTORS
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".
Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.
This is from Stoptechs site here: http://www.stoptech.com/whitepapers/brake_systems_and_upgrade_selections_122701.htm
And this:
Crossdrilling
Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40’s and 50’s, not a whole lot. Rotors were first ‘drilled’ because early brake pad materials gave off gasses when heated to racing temperatures – a process known as ‘gassing out’. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ‘somewhere to go’. It was an effective solution, but today’s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don’t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads – sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)
The one glaring exception here is in the rare situation where the rotors are so oversized (look at any performance motorcycle or lighter formula car) that the rotors are drilled like Swiss cheese. While the issues of stress risers and brake pad wear are still present, drilling is used to reduce the mass of the parts in spite of these concerns. Remember – nothing comes for free. If these teams switched to non-drilled rotors, they would see lower operating temperatures and longer brake pad life – at the expense of higher weight. It’s all about trade-offs.
from here: http://www.teamscr.com/rotors.htm
Brian
anytime you remove mass from the rotor you reduce its effectiveness. period. end of story. even ignoring the issue with stress risers. a rotor with holes in it is patently less effective than one without.
they're simply not found at the track. drilled is all about the bling.
they're simply not found at the track. drilled is all about the bling.
ShelbyGuy said:
:thumbsup: Drilled rotors are bling......
:beer: Nice brake pic :-D
Excellent - thanks.Cobra-R said:
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