co4wheel

Heat has to be absorb by the mass of the rotor. During heavy braking MASS is more important then your Dissipating idea. Both are important but mass is the most important.

Read this. http://automotivethinker.com/brakes-...d-and-warping/

Lots of people selling higher priced parts LOVE crossed drilled. After all, they look cool, cost more (must be better) and you get to buy them more often (they crack).

co4wheel

Frozen rotors work. Don't know why but they prevent warping and cracking at extreme heat.

bbrowncods

To each his own. But no way you can convince me that a solid rotor has better braking performance than a comparable drilled or slotted rotor. Each has its advantages and disadvantages. The problems associated with the GX brake system can be improved or eliminated with better rotors and pads.

co4wheel

A good set of something like a HAWK or other good pad will be your best bet. That and a set of good rotors that have a internal Directional Vane Setup. That is with out a doubt the best way to go if you want the overall best internal cooling (directional vane) and mass (not drilled). OEM are not horrible but you can do better. Especially if you don't care about dust as much as you care about performance.

fastnoypi

In all the competitive motorsports where braking is crucial, you won't find anyone using cross drilled rotors. It is old tech.

Indy cars and F1 don't even use slotted rotors and will exceed speeds and harder braking than you and I ever experienced with solid rotors. Utilizing the most contact heatsink area.

Nascar and WRC use slotted rotors. While old advertising and "FAQs" say they allow outgassing and a channel for brake dust, the industry knows it is no longer needed due to modern pads. Having been to alot of events and talking with team mechanics, they find slots useful as an visible indicator for minimal nominal thickness before they need to be replaced. Otherwise it is just less surface area and heat sink mass.

There are really no advantages to drilled rotors, its parking lot jewelry. You have less heat sink mass, stress risers, and the least amount of friction surface area.

co4wheel points out a great quality about what you want for a rotor. A rotor with vented internal directional vanes will perform better than a crossdrilled rotor. The width and length of the vanes provide more heat sink mass for cooling. Here is a good read on vane differences http://www.ebay.com/gds/Brake-Rotor-...8353072/g.html

for normal everyday use, your setup is probably adaquate

NMBruce

Even though all brake systems are basically the same, you can not compair a Indy or F1 to stock vehicle braking system, they will use solid rotors because they need to hold up for the length of the race and see conditions that we will never come close to and have designs that our cars dont have to get rid of the excess heat build up. Now if you go to Racing like say PCA racing or NASA racing, you will see slotted rotors and cross drilled. I don't like cross drilled because they can crack from the heat build up, saw this a lot at the track back in the mid-late 2000. I ran stock solid rotors and upgraded pads on my S2000 for many years. Slotted rotor on the other hand to me still have a place in racing and on performance track days and street cars, Brembo has even start working on different slotting for different applications. http://www.brembo.com/en/car/racing-professionals.

As for my GX470, it will get slotted rotors, not because of gas build up, they help disapate water film build up and help to keep the pads cleaner.

I think that good brake pads are the biggest bank for the buck when it comes to brakes and keep you calipers clean and in good working condition and don't forget the fluid.

chiph9

The previous owner had put slotted+drilled rotors on my GX. It had mild brake vibration when I first got it, but within a year it had progressed to where if both sides happened to line up, the vibration was severe, to where my confidence in it's ability to stop was really low.

Based on other repairs from the PO (they had put Chinese tires on, etc), I expect they had bought the cheapest set of rotors they could find.

I replaced them with OEM parts (and pads) several months ago, and I've been very happy thus far. Stopping ability is what it should be. Am I going to track it with these pads? No way. It's a street/dirt vehicle.

Chip H.

bbrowncods

Agreed. Indy/F1 compared to street? Give me a break (pun intended). Their rotors are floating carbon composite costing thousands of dollars. Apples to oranges and doesn't make our rotors (slotted/drilled or not) "old technology". Who is driving on a track? For stopping power slotted/drilled beats solid steel. Look at the major street sports cars

co4wheel

Not true. It's basic physics. Installing drilled on a car/truck not designed around it from the start REDUCES mass. That is bad no mater how you slice it. Read the link. Cooling is not really increased enough to compensate. You can not compare a car designed around drilled rotor to a truck not designed around drilled rotors. Your adding a rotor with less mass, huge increase in cracking potential. What you need is MORE mass and less chance of cracking. It's very basic really.


http://automotivethinker.com/brakes-...d-and-warping/

Trying hard to think of a single TRUCK that has drilled rotors. Every truck I know of has bigger non-drilled rotors on their HD versions that are designed for towing from the factory. They have 600+ ftlbs of toque. Are amazing machines compared to what they were 15 years ago. But still use Solid Rotors. Because they work better.

NMBruce

from what I know and have read, slotted and or drilled might be better in some applications, like rain. For long lasting, solid or slotted are much better, the amounts of surface lost for a slotted rotor is minimal. In a long distance race, solid/slotted are much better at staying together and lasting the race.

maybe high dollar drilled rotors or new technology rotors will last and serve what you want, but I have seen them crack on BMW and Porsches at the track and would never buy them.

Again, most people look at pads and rotors, but forget the brake fluid. As an instructor at HSDE events, I was changing my brake fluid every 6 months and using good pads and solid rotors, went to slotted rotors when the stock wore out.

MattJO

Who indeed is driving their GX on the track? What makes you think a GX needs slotted/drilled rotors?

Better braking can be achieved simply with A) good tires B) good pads. If you're having issues with stopping power you're best to start looking at those 2 options first.

Major street sports cars are also into "looking" the part. It has nothing to do with providing "stopping power". As the holes are meant for is allowing gas to escape, which only helps extend the stopping power on the track, not increase it. But that is all null as the pads we use today do not give off gas. Also, notice how the major sports cars also increase the diameter of the rotor to make up for the loss of mass by drilling. Because greater mass = greater performance.

If you like the looks, that is all good. I wouldn't go stating that they actually help you stop better though.

chiph9

Good point about changing the brake fluid. This is something that is often overlooked.

I do it every 3 years. If you live near the ocean or great lakes, you should be doing it every 2 years.

Chip H.

SkeetShoot

I have the powerstop slotted and drilled rotors. They work nicely. I will likely get a set for the rears as well. On a separate note, I actually think my e-brake is dragging right now. I'll have to look into it this weekend.

fastnoypi

beat me to it. The physics are the same in the track application and street application. The only difference is the material choice. F1/ Indy use carbon ceramic rotors matched with pads formulated to have bite at high temperatures. They actually perform awfully at "city driving" speeds.
Street cars need to use materials suited to have a balance between a good initial cold bite and temperatures generated averaging above speed limits.

co4wheel

I used to have some HAWK pads that would shoot Sparks out from the wheels at night about 12 feet when cold. Once up to temp they did not and they worked amazingly. That's not a problem on a track car but on a streetcar you have to get a balance between hot and cold temperature response.