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I prefer drilled over slotted.
Drill came first and prove to be pretty efficient.
The slotted came few year after. The theory that is introduce is that the air should flow better to cool down the pad and the rotor as the wheel spun, and you have more contact surface than the drilled version, which should provide more braking performance.
The only thing I don’t like about the slotted version we use at our shop is that corrosion will build up in the groove and at a point of time the rust will come at a point that it will hit the pad and cause noise when coming to a full stop at low speed. It might only be the manufacturer design (zinc coat) which was not doing its job but after many come back … we decided to forget about slotted version from multiple comeback.
On the other end the drilled version seems to do a great job when it come to applying lots of heat. As long as you know you purchase a good quality rotor. Having a cheap one will cause warpage or minor distortion and you can’t really machine them.
The pad might be the little guy that make you feel you had more braking power tho. 😉
For the average driver a plain disc works best. For the amateur track star who goes to auto-x or oval track events on the weekend a plain disc works best. Using drilled or slotted, since the brakes are used harder here, they tend to crack. Now, if you are getting close to being a professional and your brakes cost more than the average used car, you will be using slotted or drilled discs made of special materials.
So, for the average driver, buy whatever looks good to you since this is an appearance upgrade only.
the primary function of drilled and slotted rotors is too not only cool down the rotors but it is also used too prevent gas fade, as the rotors get hot as well as the pads or as the car is moving very fast a gas can be produced buy the pads as they get very hot and a small film of air can form between the pads and the rotor contact surface, this can make the brakes feel very ill too respond.
cross drilled holes and slots are put into the rotor too allow these gasses too escape and allow the pads too come into contact with the rotor wich allows for more confident breaking even after the rotors and pads get very hot, in many cases during breaking on high performance vehicles the rotors will get so hot they glow!
for this reason under normal conditions cross drilled and slotted rotors are almost pointless for anything besides looks… there are also “criogenically treated rotors.” i hope i spelled that correctly, these cast iron rotors are heated and then dipped in liquid nitrogen which hardens them for hard red hot breaking.
when it comes too getting cross drilled rotors it is best too get rotors that have those “cross drilled holes” naturally in there cast, rotors that are drilled after being cast are known for cracking, slots are different however i think anyway.
if you really want hard core high performance the best thing too get is carbon ceramic rotors which are next in hardness too diamond but much lighter than cast iron rotors reducing un spung weight and are heavier duty obviously, they almost never crack or warp, but they can cost a furtune over the cast iron rotors.
^^^^Good writeup
A few years ago I watched the entire 24 hours of La Mons on TV (excluding the cat naps). Watching the cars drive through the night with their glowing brakes was amazing. It looked like they had yellow to orange lights mounted behind the wheels. Imagine having to work on these brakes when they come into the pits.
For a street driven car you can make major changes in braking effectiveness with pad choice. Go to an auto parts store and you will be offered good, better and best. What they are aelling is a pad that works when cold, is easy on rotors, produces little dust and is quiet. However, the bite may not be the best.
Some pads are made that work best cold and some best hot. A pad that needs some heat to work can produce panic moments at the first stop light. Pads that need heat to work are used on the track. However, these pads usually ultimately have the most bite.
Pads are also made with various coefficients of friction. This is the bite I mentioned above. I like lots of bite but not too much. The forces needed to work the brake, clutch and steering should harmonize. Too little or too much pedal effort throws me off.
A good pad will also have lots of modulation. You don’t always want or need to brake hard.
Some of the better pads are known for dusting and if you like your alloy wheels to look nice these may not be what you want. Ceramic pads are all the rage now because they produce so little dust. I don’t like them. Not enough bite.
I have pads on my car that work best at subfreezing temperatures. You never know, that emergency stop you have to make may be at the end of your driveway.
good point and i will also add that Carbon ceramic break pads commonly used in high performance applications are not nessisarily good for street use, at least for comfortable breaking, break pads for more high performance applications are designed too work best when they are hot, carbon ceramic pads will usually not stop a car as well cold as normal semi metallic or ceramic pads, and may be harsh on cast iron rotors, they can also make a sqeaky noise when cold, but get them hot where regular pads incinerate and watch them bite the cars rotors real good!
but that’s for a day at the track, for average driving i like ceramic pads, they break good at regular driving temps but last a little longer and don’t get dust all over your aluminum wheels like semi metallics.
another good upgrade big bang for buck which eric has suggested already in one of his videos about modified cars is stainless steel braided brake lines, make for a much firmer pedal and much better breaking response, plus they look sweet!
Do cross drilled rotors wear pads faster than blank rotors? I replaced my stock blank rotors with drilled ones in august 2014 and find that my pads is ready to be replaced. However, I do a lot of driving…putting on 25000 miles a year.
I wonder if this is one of those topics where myth has become reality. Years ago, when drilled rotors began to become available for common vehicles, the technical write ups in automotive publications like Road & Track explained that it was for better braking performance in wet conditions. These theories about better cooling and such weren’t part of the discussion.
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