New Rotors

[lexdog]

Its about that time to replace my Rotors One is pretty warped and needs replacing. Ive wanted to upgrade my brakes and rotors anyways with 20" inch wheels

I feel like ive lost some braking power. Ive been researching new rotors and have came across quite a few articles about slotted, drilled and slotted\drilled rotors and have came to the conclusion that unless you the roters has been cased with drill holes drilled rotors are prone to cracking and do not provided any significant improvement in braking performance. Was wondering what your opinions were on slotted, drilled or slotted & drilled roters ?

Heres is one article I came across

While I'll agree to a certain point, here's some quotes from many known brake engineers and brake manufacturers in regards to slotting vs. drilled vs. normal.

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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."

[Grumpa72]

If you plan on racing your RX, you might want to think about upgrading to slotted or drilled rotors. Oth, you may also be replacing rotors sooner than you expect.

The only vehicles that I see with slotted/drilled rotors are extreme high performance road cars and teenagers and their rice cars. My son wanted to do this to his Honda and I said he could when he had finished paying me for the car.

Stock all the way for me.

[lenore]

Buy some Brembo rotors, and Akebono pads and you will be set.

[HeftyJoe]

Sorry, was searching on tires and came across this old thread I thought I'd bump.

For street use a slotted rotor would be the best upgrade. Drilled rotors do produce crazed lines and cracking from the drilled areas. Slotted or drilled rotors will help with braking performance but at the expense of driveability. Driveability is a a metric that compares comfort versus performance. A track car can haul butt but is rough on the backside versus a Cadillac with air ride suspension that floats down the highway but doesn't stay there for long when you push it. Anyways, a slotted or drilled rotor will cause a vibrating pedal feel and brake squeal will become impossible to eliminate. On an all out track car the track conditions are relatively clean and pads wear out so fast that they are replaced before they squeal. However, listen to a WRC rally car which is exposed to real world dirt and water conditions and those brakes squeal like crazy - like ear piercing loud. One last thing, keep in mind that a set of high quality brake pads are already slotted to deal with the out-gassing of hot brake material.

To continue with my rant I will say that with most any performance upgrade you have to look at the bigger picture. Does the stock caliper exert enough braking force to warrant the slotted rotor? I have a Nissan 350z Track edition which comes with the Brembo 4 piston calipers but has a smooth face rotor. That setup would benefit enormously from a slotted rotor to take advantage of that 4 piston caliper. Our Lexus RX3xx just has a 1 piston caliper. Nissan probably didn't put a slotted rotor on there from the factory because of increased cost, increased brake noise, and increased pad wear. In other words if you thinking of going with the slotted rotor I would probably look into a caliper upgrade as well. I will admit though that after having driven in a car that has 4 piston calipers I would advocate that every car should have them at the very least as a safety feature. I've had situations were someone slammed on there brakes in front of me for some reason or another and I can outperform them in braking distance so well that I can quickly back off and stay out of "too close for comfort" situations. Since owning the 350z I've been hooked on looking at a vehicles 0-60-0 times which gauges both acceleration and braking times.

[wwest]

Insofar as I know there are only TWO reasons for using drilled or slotted rotors, Brake pad "outgassing" under SEVERE use, and RAIN.

Very few passenger car drivers ever use their brakes in any manner that would be severe enough to result in outgassing of MODERN day brake pads. Trying to maintain a speed slightly above "sensible" while driving down a curving LONG mountain pass road, for instance.

Here in the Puget sound area we often have, encounter, the RAIN situation.

My 78 911 does not have drilled or slotted rotors and I have had instances of sliding almost into an intersection as a result. My '01 911 does have drilled rotors and I haven't notice any such problem. On the other hand back when the '92 LS was our daily driver, as is the RX300 today, I haven't had any instances resulting from rain or water puddles and both of those have SOLID rotors.

But I am intrigued by the industries latest idea which seems to be to pre-dry the brakes via slight application of braking pressure if the windshield rain sensor triggers.

[KBRX330]

I am very satisfied with the Raybestos Advanced Technology rotors & ceramic pads on my RX330. Way better than the brembos IMO.

[SmilingBoognish]

I wouldn't consider anything other than plain old vented rotors for an RX. Slotted rotors are beneficial on a track, but they will eat your streetable brake pads a bit faster than necessary on the street.

Cross drilled rotors are just bling. Yes, new Porsche's have cross-drilled rotors. However, if you talk to anyone who regularly tracks their Porsche, they upgrade to slotted or sometimes solid rotors after the factory rotors crack.

Here in the Puget sound area we often have, encounter, the RAIN situation.

My 78 911 does not have drilled or slotted rotors and I have had instances of sliding almost into an intersection as a result. My '01 911 does have drilled rotors and I haven't notice any such problem.

I'd be willing to bet bet you a beer that the difference you are experiencing has more to do with your tires and brake pad material than it does with your rotors. ;)

[ukfan4sure!]

Go stock. No need for other.

Rotors drilled improperly will show cracks over time and could lead to catastrophic failure if not checked.

BTW, drilled rotors do NOTHING for outgassing. Thinks about it. Where is it going to go sandwiched between two brake pads?

Slotted DO outgass, though but will significantly affect pad wear.

Stated simply.....you just don't need it.

[wwest]

I wouldn't consider anything other than plain old vented rotors for an RX. Slotted rotors are beneficial on a track, but they will eat your streetable brake pads a bit faster than necessary on the street.

Cross drilled rotors are just bling. Yes, new Porsche's have cross-drilled rotors. However, if you talk to anyone who regularly tracks their Porsche, they upgrade to slotted or sometimes solid rotors after the factory rotors crack.

Here in the Puget sound area we often have, encounter, the RAIN situation.

My 78 911 does not have drilled or slotted rotors and I have had instances of sliding almost into an intersection as a result. My '01 911 does have drilled rotors and I haven't notice any such problem.

I'd be willing to bet bet you a beer that the difference you are experiencing has more to do with your tires and brake pad material than it does with your rotors. ;)

You owe me a beer...!

With the 78 in the rain if I remember to dry the brakes via a slight application before I really need serious braking my stopping distance is acceptable.

My experience at looking over the various cars participating in the 24 hours of Daytona for the past seven years is that almost all run solid rotors with center venting/cooling.

[wwest]

Go stock. No need for other.

Rotors drilled improperly will show cracks over time and could lead to catastrophic failure if not checked.

BTW, drilled rotors do NOTHING for outgassing. Thinks about it. Where is it going to go sandwiched between two brake pads?

Well, even were the drilled rotors not actually each made up of TWO rotor "plates" with the center open for venting and cooling, the drill holes would provide space for the outgassing.

Slotted DO outgass, though but will significantly affect pad wear.

Stated simply.....you just don't need it.

Ask me why I care NOT how fast my brake pads wear....!!

Relatively inexpensive preservation of MY LIFE.

[NJerseyDan]

My rotors recently started shaking read damn bad. So Ive been researching rotors online and just bought some aftermarkets off ebay today. http://cgi.ebay.com/ebaymotors/ws/eBayISAP...T&viewitem=

Wish Id read this forum before buying. You guys really think those holes are gonna lead to cracking? These have the holes and the slots as you can see. I just figured I warped the stock ones, so what would keep it from happening again? i dont drive crazy but I do drive aggressive. Okay. I do drive crazy. So I figured I needed something that could take a little more heat. wish me luck fellas