10-HHR-SS

Well i dont want to turn this into a full discussion of who is right and who is wrong but on one point i have to say is i completely disagree that a solid rotor dissipates more heat. Slots or holes let in cooler air and is proven to dissipate heat better and yes some rotors can crack in those places if the rotor cant handle the thermal cycling but if you use a quality rotor this shouldnt happen. I have been a Willwood dealer and installer for quite some time and have read many studies on this so IMO i disagree. But like i said i didnt mean to make a discussion on this, i just want some slotted rotors.

hyperv6

The fact is there is a lot of false info on drilled and slotted rotors out there. They do not dissipate hear faster and they do not cut fade. This is one of the big lies that has been around for a long time and lives on in the internet.

The only reason they are around it to make them look cool not be cooler. The holes do nothing but remove metal and less metal means less heat sink. So in reality the drilled rotors will run hotter and absorbe less heat vs a solid rotor.

In the old days people drilled them to out gas the old pads Todays pads do not need this anylonger. They also drilled the rotors on race cars to lighten them up for less unsprung weight.

Today they drill them for looks and to make money by charging more for them.

The Slots do have a marginal effect in cleaning the pad off. This is a slight help but not much on the street.

If you like the look of the drilled rotors by all means buy them for the looks. But if you think you are getting a better part save your money. The best rotor you can buy is a solid stock replacment for your stock system. The only ways to improve your brakes is to go with better material pads or larger aftermarket brake systems.

They key to a good brake system is to get the heat out of the pads. Better material releases the heat and the roto works as a heat sink to draw it away and dissipate the heat. The hole do not cool but they do remove metal from the rotor and make that much less metal to absorbe the heat.

I work in the performance aftermarket and deal with companies like Hawk, EBC, Powerstop, Baer, Brembo, Stainless Steel Brake, Bendix Willwood and others. I deal in stock replacement to full blown race. When you have people come in like the owner of EBC and he tells you that Solid rotors are the best and the drilled only make a lot of money you take notice.

I have used drilled for looks on two of my past cars. To be honest I find them more noisy than anything. I just took them off my GTP and went back to the Bendix replacments. I am glad they are gone and they were a heck of a lot cheaper.

Trust me GM is using the right rotor.

You can disagree all you like but it does not change the truth and what most Major MFG's will say. There are a few who will make some kind of claim of improved cooling but if they had to prove it they could not. The fact is they want you to spend 3 times as much on your rotors that cost so little to drill.

It is kind of like the saying "There is a Sucker Born Every Minute". Many think PT Barnum said it but the truth is it really was his competitor David Hannum. I guess you can't beleive everything you hear since the facts get in the way.

hyperv6

Here is what Willwood states.

What's the difference between slotted and drilled/slotted rotors? Which rotor will be best for my application?
A:
PSlots or grooves in rotor faces are partly a carryover from the days of asbestos pads. Asbestos and other organic pads were prone to “glazing” and the slots tended to help “scrape or de-glaze” them. Also, cross-drilling 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 began to break down at extreme temperatures. This condition is often referred to as “outgassing.” When it does occur, the driver still has a good firm brake pedal, but a significant reduction in friction. Normally this only happens at temperatures witnessed in racing. However, with today’s race pad technology, “outgassing” is no longer a concern with pads designed for racing.

So in the final analysis, drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood provides rotors slotted, drilled or plain. For most performance applications, slotted is the preferred choice. With certain pad material, slotting can help wipe away debris from between the pad and rotor as well as increasing the coefficient of friction between the rotor and the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage; however, for street and occasional light duty track use, they will work fine. For more severe applications, we recommend slotted rotors.

Note the last part about they will not recomend drilled for severe applictions. Only slotted. Most real race brakes we sell will be slotted from most MFG. Even Brembo will not recomend their drilled for track use.

The bottom line is if you are doing track time with a very aggressive pad slots will help. On the street it really has little effect unless you are running very aggressive pads that will eat the rotors anyway.

I am not trying to start an argument. I just hate seeing people spending more money for brakes that really do not much better.

FYI If you work with Willwood they have the parts to do a big brake package. Someone here last year did one and it came out nice and better than the Brembo option. I forget how big they were but they did run a larger rotor and a better caliper. The Red Calipers looked good and the rotors were slotted too. Might search around here as there was a tread on it.

Mrs. DLVRNIT

Thank you hyper6 for the Wilwood info as that is the same information we had read some time ago (can you say pre-alzhiemers) ! Nice to stand corrected on the slots that they are there to help in the cleaning of the pads! We're just waiting for our Wilwood Calipers with 2 pc Plain Rotors to arrive any day now as we really need a way to slow down this Beast of a Trifecta Tuned 2.4 ..... Thanks to 10-HHR-SS for keeping the thread civil .....

Best-O-Luck and Enjoy Which Ever Big Brakes You Choose to Install ,

bartSS

hyper youre absolutely right. Thats why i bought the brembo setup for mine.

ATLsilverSS

Im not saying that either is better but I personally find it amusing that 99% of all aftermarket big brake kits ever made have some kind of drilled/slotted rotor

hyperv6

It is because people precieve them as being better because they have holes.
Also it is because they look nice inside 18-20 inch wheels. Nothing to be confused about other than just plain old marking.

It is not much different than most cars with scoops and spoilers on the street. They are there because they make it look cool and not really so much to increase performance at highways speeds. There are some acceptions to this but they are limited.

Almost any company that makes a rotor with holes anymore will not really recomend them for track use or heavy track use. So if you can't race on them do you really need them on the street?

As for slots they so help with the race grade pads. The agressive pads are very abrasive and can leave deposits on the rotor or a lot of dust. [IF you have ever changes a tire on a pit stop you know what I mean]. The slots will help remove this and brush it off. They are even of more use on off road trucks as they will sweep mud off when off road. So slots so have a little use but not so much on the street as you normally would not use a race pad on the street.

Note too Brembo is not like they once were where they were nothing but high end brake system. They went public and also entered the OE market with good systems but not the high end systems they used to only make.

While the OE systems are good they are still not the same as their better systems like on the Enzo and ZR1. Think of Brembo as like the Porsche company they have their real high end sports car and they also a very nice but much cheaper Boxer. At one time Brembo were only on the most expensive cars, Bikes and race cars with only high end systems.

System like ont he Camaro are very good but is a less expensive system than they used to offer. I guess you can say they have found a way to bring better brakes to the masses with out a system that cost more than the car.

mistermike

Modern brake pads do not outgas the way organic pads did, so there is no need to provide an escape path for gasses you're not generating. You can make a slight case for slots, because they will clear water a bit faster than without. Holes in this day and age are a joke. The produce stress risers, cracks, and do nothing except reduce the available braking surface area. The only reason high end brake companies produce them is because people stupidly insist on buying them, and they don't want to see their competitors get the sale.

IgottaWoody

heres another take...for every hole drilled out....thats just that much LESS area of pad contact..and that much less braking ability..in race form the rotors are much bigger and can make up for lost surface contact area.... do you really want to take a stock rotor size and effectivly make it smaller? Drilled and slotted rotors are in kits for the same reason that Video and navigation systems are factory installed, to sell the package! Do you really need them? No....(besides the same toys can be had much cheaper aftermarket).It looks racy so its appealing to the wanna look racy crowd.

Michael20832

I purshased slottted and drillled on alll four corners. Best upgrade I've done next to cat back exhaust. i have to use my SS as my company car and my stopping is much better and they look great with the stock wheels.When i have the extra 800.00 buck to upgrade to front brembos