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I was just reading up about this the other day and I never knew there was such a big debate regarding the benefits/disadvantages of cross-drilled and slotted brakes. If they're not any better, then why do companies like Ferrari, Porsche and others use them? What do you guys have to say is the best?
It would generally depend on your rotors size, caliper, and usage...
But if you want to replace OEM rotors, drilled, slotted, or drilled and slotted rotors generally offer worse than stock performance in normal conditions, cost more, and tend to be poor quality and crack.
slotted would be best as the drilling takes off a lot more surface area, reducing braking efficiency, and you probably wont be doing anything where you need the drilled holes to cool your breaks.
slots and drill holes help cool the brakes better, for track use.
slots and drilling aren't for lightening the disk or cooling(except on race or high performance cars) they are for squeezing the water off the disk so your brakes act quicker in the rain.
It's good for track use where you're going to be doing a lot of heavy braking. I believe (and sorry if I've got this wrong) but slotting is also to help bleed off gases produced by some brake compounds in order to ensure optimum brake performance. If you're going to be doing mainly daily driving then blanks or at the most slotted brakes are what you want to go for. Cheaper that way too.
Drilled and slotted tend to have best performance, but they aren't very suited to daily driving because you're not going hard on the brakes like you would on a track car.
Usually slotted are preferred by high end auto manufacturers.
Just plain rotors work for high performance cars if the brakes and pads are carbon ceramic (VERY expensive ($8000 for a front set on a BMW M3), but insane stopping power)
Slotted if you are sticking wih OEM size brakes...cross drilled brakes that some companys offer are also a thicker material like Baer and Brembo, but you also need their larger calipers too. But IMO the slotted rotors are more durable.
Performance Friction also offers a dimpled rotor that has is not a harsh on a Street brake pad as would a Slotted rotor.
http://www.jegs.com/p/Performance+Fr...10002/-1/11753
Slots are used for more with Gas build-up...yes funny as it sounds..but when your brakes are glowing red hot the pad material actully lets off some gas...this is what brake fade is.
http://www.ebcbrakes.com/QandA.html
You can also get brake fade from the Brake fluid actually boiling. Usally due to repeated over use of the brakes.
The Vanes inside the rotor is what really does most the cooling.
If you're not doing performance driving then stick to heavy duty stock. If you can lock up the brakes it doesnt matter what the ad on tv tells you about stopping distance.
If you cant lock up the brakes then you probably need to fix something or get your money back.
Drilled holes, slots, etc, are useless. Stick with plain face rotors for the strongest, longest lasting setup. Anything else compromises strength, durability, and just eats up brake pads faster.
Soulburner nailed it. The shop where I work has installed many sets and we have never found any practical benefit. we have run into all issues mentioned by Soulburner. The ONLY reason to install these on a street car is looks(w\ an open wheel they do look good)
That is unless your doing any kind of performance racing.Quote:
Originally Posted by Soulburner
drilled and slotted started as a racing thing to cool brakes, its been implemented in super cars/sports cars as a "race fashion." It has no place outside competition. As someone said earlier it depends on a couple things, but usage is the biggest and boldest here. Super cars tend to always have them, cause, well, what else would you really buy the cars for, surely not to take your kids to school everyday. I go with cross drilled, if i am currently messing around with autocross as I do on occasion. Have not in quite a while. I sold my subby.
To add, there is very small gains with slotted. The most expensive and popular are drilled and slotted on one rotor :down: Too much surface area loss.
Flat, use some ducting for track days
Go with slotted only for tracking. Drilled really have no use for most people unless you're doing some serious racing.
Otherwise, stick with blanks to get the best performance. Use a high performance pad such as Hawks or Axxis and swap in a high performance fluid such as Motul RBF400 or ATE Super Blue.
For daily driving, drilled will rust and crack much easier. Slotted will only wear your pads down faster.
drilled shouldn't be used at all, imo. The holes just create stress points in which can cause cracks. This is because the manufacturers just drill the holes in. I've heard that Porsche forges the holes and they're not drilled so the holes aren't areas that are under extra stress. Ferrari uses them on their carbon ceramic brakes which is a different composition than the steel discs that we normally use.
QFT! The water will create a steam barrier between the pad and rotor. The holes or slots let the steam escape.Quote:
Originally Posted by fart_plume
Yup, but for everyone else...is this really worth the risk for "looks"?Quote:
Originally Posted by party animal
http://www.powerslot.com/images/deal...cked_rotor.jpghttp://www.devtools.org/rus/mtimages/rotor-cracks-2.jpghttp://www.wam.umd.edu/~greghess/rotor2.jpg
Rotors crack even without the holes. Why would you want them even weaker.
Rotors crack like that when idiots by 100 dollar rotors and think they are ferrari quality. Rotors that are post drilled are doomed to crack.
I have slotted on my car but that's just because I got a killer deal on them from an ebay auction. But those + the ceramic pads I got with them stop on a dime, and when wet they still stop super fast, enough to kick my ABS on lol.
I like to use slotted instead drilled rotors. Its a discussion that goes along the lines of Ford vs Chevy. I have used all slotted rotors on my SCCA and drag vehicles. I do not like th e drilled rotors due to prone of cracking.
The slots and holes are there for the gas to exit. When you brake heavily, there is a gas that forms and wants to push the pads apart from the rotors. That will cause brake fade. The slots and holes are there so the gas excapes.
If you do not plan on doing any kind of racing, stick with plane jane rotors.
These days, pads don't release gases. That was back in the day. Slotted rotors give a better initial bite, but at the cost of pad wear. Drilled (not forged with the holes) shouldn't be used at all on a track. On the street, they might be okay. But why pay more for looks and less thermal capacity?
exactly, the one real reason you might even need slotted or drilled is in racing applications, in which it is NOT a smart idea to go budget stuff, i figured this out the hard way, as stated earlier drilled does have the advantage of pushing water for better brake reaction in the rain, but on a normal road car, this still is overkill really.Quote:
Originally Posted by Nanometer
I thought newer pads didn't produce any gas?
They don't, that was back in the day when they were first introduced.Quote:
Originally Posted by Soulburner
slots are just there for cooling now.