highwaydrifter Posted October 5, 2004 Share Posted October 5, 2004 [quote name='apexjapan'][quote name='Xenonk']If anyone ever drove on a hot day at the track without the use of track brake pads, you will know that it's fairly easy to overheat the pads, or "glazing" them.. basically rendering the brake pad grip as much as a block of ice rather than a solid grind stone. If anyone of you ever drove on the "Dragon" you will know that even riding down the 14-mile, 1-mile decent mountain drive at 40 mph can build up some serious heat and possibly glaze you pads and boil your brake fluid. [/quote] I had some serious pads and slotted rotors on my B4 twin turbo when doing the Tsukuba Time attack. Fantastic braking from slotted DBA two-piece and semi-carbon pads. Absolutely fantastic. The pads also wore out in 1500km of driving with about 40 minutes of total track time mixed in, and they also (edit: Totally) ate up the DBA rotors, which I've found are normally so hard they glaze up if you don't use at least a semi-aggressive level of racing pad with them. Which is why I wouldn't suggest such a level for people that actually drive on the street - yes, you may have far more braking than tyre grip, but can you afford to be changing them out every month? :D Porsche supplies the cross-drilled look because, simply, it looks great. And their customers want their car to look great in every aspect, all the way down to the brake rotors. They get around this by creating the holes in the casting process, rather than drilling them afterwards. Thus manufacturers of rather decent price/performance rotors, such as DBA, openly recommend going with their slotted rotors if you are going to do some serious circuit racing. I'll be honest here, though, in saying that for many of the weekend warriors at the circuit, non-slotted rotors would likely be just fine. The problem that actually arises is one of driver skill. There are means and methods to getting the most of your brakes at the circuit, and such skills are rather important all the way up to F1, for even if you can afford to replace your rotors and brakes every 10 seconds, you will be faster if you can make your brakes last that much longer than your opponents, saving you that much more time in the pits. I used to think I needed more and more brakes, but as my driving skills rose, I realized I simply wasn't using the optimal braking points and overshooting/late braking, which not only caused me to be on the brakes that much more harder and longer, but slowed down my entry speed (and thus exit speeds). Maybe not the most politic of things to say as a friend of the tuners, but an honest one, before you drop a wad of cash to decrease your braking distances by 5 feet, spending some time learning proper braking techniques and braking points may not only save you money, but decrease your time around the track much than those 5 less feet would. Cheers, Paul Hansen [url]www.apexjapan.com[/url][/quote] very good post, and very very true. My own take is this, on teh track that is very true, but on the street where drunken grandmas swerve at you and homicidal truck drivers slam on their brakes or cut you off biger =better as far as brakes go. I loved my stop techs for the simple reason of they got me out of several crashes just like that, so that 5 feet or so may not mean much on the track but in the real world htat 5 feet saved me from being hurt and or totaling my car. ON the track it comes down to driver skill on the street its all about hardware (and skill but the hardware is what will make or break you in those situations that you cant see coming). Just my two cents of course.. Link to comment Share on other sites More sharing options...
Xenonk Posted October 5, 2004 Author Share Posted October 5, 2004 Wait til these babies come out.. I think it maybe a 370mm x 32mm 6 pot front and 332mm x 32mm thick 4 pot rears. [url]http://www.endlessusa.com/products/index.php?id=4[/url] Keefe Link to comment Share on other sites More sharing options...
Guest jpkad Posted October 5, 2004 Share Posted October 5, 2004 [quote name='Drift Monkey'] Hmmm....so my presumtions we're generally right. Well at least we got Paul here with some track time to reaffirm it. :D Which brings me to the question: If cross drilled rotors are so prone to breaking, why do manufacturers like Porsche equip them as OEM parts? DO they assume that the owners never track the car? Do they profit off of these cracked rotors?[/quote] They don't crack nearly as often as some people would lead you to believe. Porsche and other high end car manufacturers won't equip their cars with products that are prone to failure. I used to work at a Porsche dealership here in town. There were plenty of owners who took their cars to the track regularly (most of the guys with 911s) and they never once had a problem with the brakes. Do you really think you'd pay over $100,000 for a car and have the rotors cracking on a consistent basis? Companies like Brembo and Baer do extensive testing on their cross drilled designs to maintain structural integrity while getting increased ventilation and cutting weight. It's all about the quality of the manufacturer. If you buy a cross drilled rotor from joe bloe incorporated of course you're going to have problems. People always try to take the cheap way out then complain when it bites them in the ass. The key is doing the needed research and deciding what's best for your needs. Most people here probably won't need to upgrade their braking system. I'm sure someone will post after me saying they knew a kid once who had a friend who worked across the street from a guy that knows someone whos brother is a mechanic and he once used cross drilled rotors and they cracked the second he touched the brakes and the tires came off and hit an old lady walking across the street to church!!!!!!!! OMFG!!!!! Link to comment Share on other sites More sharing options...
Xenonk Posted October 5, 2004 Author Share Posted October 5, 2004 Besides, cracking and WARPING happens the most when the brakes are not properly cooled down after a track session, or worst yet, when some typical 100 mph highway driver (you know who you guys are) slam on the brakes, or drag the brakes out to the point where you can almost smell it, immediately park the car and pull the ebrake up. It's just sick... I can't stress enough to slow down easy enough (1st, dont drive soo fast, it IS a cool down session) and let the brakes cool as you drive the last mile or so.. suffiecient cooling will prolong the life of the rotor.. Keefe Keefe Link to comment Share on other sites More sharing options...
liquidiq Posted October 5, 2004 Share Posted October 5, 2004 Of course, you really can't warp a rotor, it's pad deposits. I can link to the Stoptech article, but I'm sure you've all seen it. ;) Also, like apexjapan said, the Porsche brake rotors are CAST with holes. A lot of the other rotors are a blank, that are drilled, and that's where the structural problems come in. Also, big brake kits don't really help out on the initial stop, that's highly dependant on your tires. It's the heat dissapation over multiple stops that makes the big brake kits better. Link to comment Share on other sites More sharing options...
Paisan Posted October 6, 2004 Share Posted October 6, 2004 Drilled Rotors Crack, period, unless you have some really high end material rotors on your car such as the Compact Graphite rotors from Racingbrake or Porsche Rotors. When we started testing for Racingbrake we cracked a set of drilled rotors made of grey iron in 3 track sessions at VIR. This was how we convinced RacingBrake to stop making the drilled rotors as a standard item, they still make the drilled ones for the bling crowd but their focus is on the Compact Graphite and the Slotted Streets. -mike [url]http://TeamIAC.com[/url] [url]http://AZPInstalls.com[/url] Link to comment Share on other sites More sharing options...
DAP Posted October 6, 2004 Share Posted October 6, 2004 Are the compact graphite rotors lighter than standard? Do they wear as well? How much more expensive are they? Link to comment Share on other sites More sharing options...
Paisan Posted October 7, 2004 Share Posted October 7, 2004 [quote name='DAP']Are the compact graphite rotors lighter than standard? Do they wear as well? How much more expensive are they?[/quote] Same wweight as OEM/Street rotors. They wear like train wheels, so far on my '94 Legacy we run HP+ Pads, and did 10 track days and 15K street miles, no noticeable lip formed on them yet. My guess is for most folks these rotors would be the last ones they put on their car as you'll probably sell the car before wearing them out unless you are hardcore racing every weekend at the track with a heavy car. -mike Link to comment Share on other sites More sharing options...
Paisan Posted October 7, 2004 Share Posted October 7, 2004 Pricing is at [url]http://AZPInstalls.com[/url] check under "racing rotors" -mike Link to comment Share on other sites More sharing options...
DAP Posted October 7, 2004 Share Posted October 7, 2004 [quote name='Paisan'][quote name='DAP']Are the compact graphite rotors lighter than standard? Do they wear as well? How much more expensive are they?[/quote] Same wweight as OEM/Street rotors. They wear like train wheels, -mike[/quote] Darn. I was hopeing for a way to reduce the unsprung weight. Slow wear does say good things with respect to brake dust though. Link to comment Share on other sites More sharing options...
apexjapan Posted October 7, 2004 Share Posted October 7, 2004 [quote name='DAP']Darn. I was hopeing for a way to reduce the unsprung weight. [/quote] DBA 2-piece rotors. ;) Cheers, Paul Hansen Link to comment Share on other sites More sharing options...
Paisan Posted October 7, 2004 Share Posted October 7, 2004 I haven't used the DBA 2-piece, however I have cracked the club-racer WRX DBA rotors at VIR. I haven't been overwhelmingly happy with the DBA stuff that we've seen come through our shop, especially the ones that were sold with the perrin/wilwood 4-pot calipers. -mike Link to comment Share on other sites More sharing options...
apexjapan Posted October 7, 2004 Share Posted October 7, 2004 I used the DBA two-piece slotted rotors during many 30 minute sessions at Twin Ring Motegi and Tsukuba Circuit on the heavyweight BE B4 twin-turbo - held up great, no warping or any other problems despite lighting up all the heat bars. Cheers, Paul Hansen [url]www.apexjapan.com[/url] Link to comment Share on other sites More sharing options...
apexjapan2 Posted October 7, 2004 Share Posted October 7, 2004 There were 4 cars used in Japan to test the 5000s. All run at full pace on Motegi's full circuit with Pro-Myu HC Titan Kai pads (rated up to 800 celsius). Natch, to run full on, you have to run full on pads to match the situation. The drivers beat the hell out of the discs, but did know what they were doing (ie cooled them down on the in laps, did not throw water on them when glowing hot, did not heat spot them by standing on them when stationary after the runs etc). I also know of a rally team that were tasked with destroying them much like the test team in Japan were. The pads smoked a lot, they passed lots of high spec machinery under brakes, and all the drivers are still walking and driving around. Also, they didn't have any issues on the car ran at Fuji Speed Way which did many laps with full braking from 240km/h+ on the main straight, 2 up, weight in the region of 1620kg with the big guys riding in it. A couple of testers then ran them to death on the road - toge runs (that would be mountain driving in extremis in English), Tokyo traffic light GPs, etc. I personally ran a set WAAAY below the "minimum" thickness to see how they'd do, too. Beat them to hell with very aggressive racing pads on the road (which is extrememly hard on the rotors) - don't do this at home :wink: Suffice to say, we couldn't kill them (and we really, really tried). Even got decent wear out of them too!! :o HTH Link to comment Share on other sites More sharing options...
Paisan Posted October 7, 2004 Share Posted October 7, 2004 Maybe they have better quality rotors sold in Japan, I can only speak for the 2 sets I killed here on my Impreza at various road courses here in the Northeast US. Both sets cracked on my DBAs and yes I know how to cool them etc. I actually hold a racing liscence. -mike Link to comment Share on other sites More sharing options...
Xenonk Posted October 7, 2004 Author Share Posted October 7, 2004 As long as the beating of the brakes go, proper managment keeps them running for a long time and less prone to failure. Keefe Keefe Link to comment Share on other sites More sharing options...
apexjapan2 Posted October 7, 2004 Share Posted October 7, 2004 Erm, we tested sets pulled from normal production runs... Early ones though - which is why we were asked to kill them (in the nicest possible way of course :wink: ). I am not questioning your abilities, or qualifications Paisan - don't feel threatened. I am just relating the experieences of a few seriously hard tests that were carreid out using certain (named) pads, in situations where the testing was fiarly similar (same, heavy cars, very fast track, lots of big braking zones, high ambient temps, Evo 5s blowing up, etc.). Hell, we don't talk about this one much, but we even went to the extreme of running braking tests on the handling course, getting them nice and hot, then running the wet course which meant getting sprayed with cold water from the sides. That is aboslutely horrible for the discs as you can imagine. Suffice to say, they made it through with flying colours. I was seriously impressed anyway, and this is all IMHO after all. CHeers :) Link to comment Share on other sites More sharing options...
Paisan Posted October 7, 2004 Share Posted October 7, 2004 Cool cool, yeah it could be the batch we were running were just bad, they were bought from a local vendor in NJ who is no longer a DBA rotor re-seller. I bet the 2-piece ones make a big difference. If you ever want to test out some of the RacingBrake products let me know and I'll hook you up with them, they have 2-piece wrx ones coming out shortly, and we are about to test 4-pot calipers that use Subaru-4pot pads. -mike Link to comment Share on other sites More sharing options...
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