I am about to upgrade all 4 of my brake rotors and was wondering what do you think is better, Slotted or cross drilled? I have been told that both crack under too much pressure. I was also told that slotted is lost lilkly to crack after a few drives. So I was wondering if anyone can lend me some advise on which way to lean.

Thanks

 

Unless you have wheels that really show off your rotors, drilled or slotted rotors are not needed...........IMOP.

 

Slotted vs Drilled: IMHO go slotted, stronger, slot cuts glazing, degassing about same between them. Drilled adds sress risers, cuts out more surface area reducing friction,

 

Do you track or autocross your car frequently? If not then there is absolutely NO reason to get slotted or cross drilled rotors!

 

FB's are well braked from the factory. Some good pads and you're set.

 

I dunno, some vented rears help GREATLY.

 

Oh yeah, I have an SE.

 

drilled/ slotted rotors are not only for looks ya know

 

Drilled rotors will weaken with heat and cause heat cracks. With slotted you don't comprimise the integrity of the rotor, and it is still very effective removing the gasses. Unless you're going to be under severe braking conditions, don't waste your money, just stay with the stockers.

 

Exactly. As I mentioned above, if he tracks or crosses the car, then vented/slotted would be beneficial. As for around town or the 'occasional' race, NOT NEEDED.

 

I do.

 

I

Concur

.

 

what would u recomend for drifting?

 

I autocross freq. so I am guesing slot would be better.

 

Standard rotors, high quality units not $10 bottom-line junk.

Modern pad materials don't outgas, not after they are bedded in anyway. Probably most people never brake hard enough to bed in the brakes until that maybe first highway panic speed-drop, and then the brakes fade. This is a driver problem and a setup problem, not a brakes problem. After that incident the driver whines and whinges and buys crossdrilled rotors in an attempt to cure a non-problem.

Crossdrilling removes vital rotor mass and is therefore bad. Rotors cannot cool in real-time, they absorb the heat and then cool off while the brakes are not applied (which is 90-99% of the time). You need MASS to do this. Crossdrilling removes a significant amount of this mass so the brakes will actually run hotter at the time it counts: when the brakes are being applied.

Slotting doesn't do anything useful either. It cuts down on surface area available, mainly. It might cut down on "glazing" but glazing is only a problem, again, for people who rarely if ever actually use their brakes. If you get on there and *use* your brakes, I mean you're stomping that brake pedal so hard your seat bends and your left leg has muscles twice as big as your right, and you have a hard time seeing because you ears fold up and touch each other in front of your nose, then your pads wear out too fast to glaze anyway.

Look at the cars that are heaviest on their brakes: 200mph 3800lb stock cars, and rally cars which are often seen with brake rotors glowing orange and even yellow on night stages. They use non slotted, non crossdrilled rotors.

I get about 10k out of my brakepads. I've never changed rotors, never had one warp either. They turn funny shades of blue and purple, though

My Sentra is even worse, since it is FWD and braking throughout a corner is essential to keep it from plowing right off the road, especially in the wet. You can tell if I've been in the area for several hours just by the smell of brakepad. Not even vented rotors on it, solid discs about the size of GSL rears, never once experienced fade or pulsation. Not after bedded the pads in, anyway, the little old lady who owned it before me probably never even *touched* the brake pedal...

 

A psychiatric evaluation.

Peejay is spot on, get good brake pads, use a high quality DOT4 fluid and you'll be set for anything up to and including track days.

 

Do you use your brakes a lot while drifting?

~T.J.

 

People have told me, at rallycrosses, that it's supposed to be a speed contest and not a drifting exhibition.

Eh, I'm just havin' fun on dirt, big grins are all I want

Brakes are very important for drifting, for the weight transfer to unload those rear wheels.

Unless your'e doing D1 moron-style burnout-around-a-corner, in which case you don't need brakes or style either, just a heavy right foot and a steering quickener.

 

id recomend you get a new sport.



also i have cross drilled in my rally car and have had them bitches smokin, no cracks yet and they have 2 seasons on them


EDIT: get some porterfield race pads = STICKY AS **** the best i have ever drove

120 bucks for a set though and they dont last forever

 

My experience has favored solid vented rotors. There are performance benefits to slotted rotors, whereas drilled are for appearance only. You might want to read this:
https://www.rx7club.com/showthread.php?t=325881

Some quotes in there from the top racing brake manufacturers:

Darrick Dong; Director of Motorsports at Performance Friction: "Anyone that tells you that drilling makes the disc run cooler is smoking crack."

Power Slot: "At one time the conventional wisdom in racing circles was to cross-drill brake rotors to aid cooling and eliminate the gas emitted by brake pads. However, today’s elite teams in open wheel, Indy and Trans Am racing are moving away from crack prone, cross-drilled brake rotors in favor of rotors modified with a fatigue resistant slotting process."

Stop Tech: "StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors." (Note that even though Stop Tech sells both drilled and slotted rotors they do not recommend drilled rotors for severe applications.)

Wilwood: "Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity."

From Waren Gilliand: (Warren Gilliland is a well-known brake engineer in the racing industry and has more than 32 years experience in custom designing brake systems ...he became the main source for improving the brake systems on a variety of different race vehicles from midgets to Nascar Winston Cup cars.) "If you cross drill one of these vented rotors, you are creating a stress riser that will encourage the rotor to crack right through the hole. Many of the rotors available in the aftermarket are nothing more than inexpensive offshore manufactured stock replacement rotors, cross drilled to appeal to the performance market. They are not performance rotors and will have a corresponding high failure rate"

From Baer: "What are the benefits to Crossdrilling, Slotting, and Zinc-Washing my rotors?
In years past, crossdrilling and/or Slotting the rotor for racing purposes was beneficial by providing a way to expel the gasses created when the bonding agents employed to manufacture the pads...However, with today’s race pad technology, ‘outgassing’ is no longer much of a concern...Slotted surfaces are what Baer recommends for track only use. Slotted only rotors are offered as an option for any of Baer’s offerings."

Grassroots Motorsports: "Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the '40s and 50s, 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." ...It was an effective solution, but today's friction materials do not exhibit the some gassing out phenomenon as the early pads. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.) These holes create stress risers that allow 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...Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots across the face of the rotor can actually help to clean the face of the brake pads over time, helping to reduce the glazing often found during high-speed use which can lower the coefficient of friction. While there may still be a small concern over creating stress risers in the face of the rotor, if the slots are shallow and cut properly, the trade-off appears to be worth the risk. (Have you looked at a NASCAR rotor lately?)

AP Racing: "Grooves improve 'cleaning' of the pad surfaces and result in a more consistent brake performance. Grooved discs have a longer life than cross-drilled discs."

also from AP: "Cross drilled...can compromise disc life. Radiused drilled...mainly used for aesthetic reasons on road applications."

 

For the street and the occassional auto-x'er, you will NEVER use the brakes hard enough to create the risers that will spider into cracks on a cross-drilled rotor. I ran cross-drills on new factory Mazda for at least two years and one parking lot BMW auto-x event at TMS and the rotors did NOT develop any cracks...they crack under severe usage and heat. You simply cannot be working the brakes that long and that hard on the street, so cross-drilled is perfectly fine and safe per my first person experiences with them on a my ill-fated blue 1980 RX-7....

 

I understand a lot of the dynamic behind drifting, I was just poking fun at the fact its usually done while going really fast and you dont use your brakes extensivly hard during the process, lol. I mean, I guess you kinda do, but I was mainly poking fun at the fact that drifting involves a lot more "keep moving fast" ideals than say "slow down to keep traction through the corner" racing, lol.

~T.J.

 

The way I was taught, the brake is more important in braking your wheels loose in dirt (the only time you should EVER be drifting, and expect to win!) than the throttle. The wheels jump off the ground with the weight transfer (extreme example, but you know) and allows you to have a much more controlled slide than if you just powered into the slide.

 

Simply... I had newish bedded stock replacement breakes. After 2 laps on my own personal track day the breakes were litteraly smoking. slotted is the way to go...

 

Slotted won't reduce brake temps though. If your brakes were smoking you need to look at cooling ducts, more open wheels, or larger diameter rotors.