ERAUMAZDA

Dyre have you had a failure from rotors like this...do you have any test or numbers you can show us....


In aviation we drill holes into everything...as long as the holes are not close to each other, a circle will distribute the stress evenly. Holes will reduce the amount of interia needed to rotate the wheels.

I am more worried about the conditionof my brake ducts then the holes drilled into the rotors.

bingoboy

i have talked to people who have experience with both ends of the argument. one has used slotted rotors on track runs and the other has drilled and slotted rotors on a street FD. the track car cracked slotted rotors (just slotted, not drilled) after a few harsh runs. the owner of the FD however does not track his car, but he does run it hard once in awhile, and believes the rotors to improve his braking and reduce fade when he does short runs that require semi-frequent harsh braking from up to 100 mph. people will argue all day about whether or not they work.

as for my beliefs, on a street car you would probably never use the brakes hard enough for them to matter much, but also wouldn't push them hard enough to crack them. for a track car, you may actually get some use out of the slots and cross drills, but it comes at the price of having to replace your rotors after a day of racing. the cracks i have seen first showed up as small hairline crack leading from one slot to the edge of the rotor and only one one surface of vented rotors. on a track car running rotors like these, the brakes are inspected regularly as well so i doubt there is much chance of them causing real harm if they begin to crack.

there are also the claims that they improve wet weather braking and lower braking temps to decrease the chance of rotor warpage and i have even heard of law enforcement and emergency vehicles using drilled brake rotors. also...many popular brands of rotors associated with slotting and drilling are NOT cast with the grooves/holes in them. they are professionaly CNC machined into blank cast iron rotors. brembo and powerslot rotors are both cast as solid pieces, and then drilled and/or slotted. if you buy rotors from someone who is selling blanks that have been drilled/slotted, it simply is a matter of them having it professionally done vs the manufacturer drilling it themselves. one is just cheaper for the buyer .

Dyre

Brake pads havent 'gassed-out' since the 50's- Materials have changed quiet a bit from then-

And Im not starting an argument about this- I dont need this forum for tech, and I don't want to hear the half tech from this board... I just wanted to know if they exsisted or not.

Apparently this board isn't really usefull for that anymore either.

n4ji

iTrader: (1)

They do. The cross drilled holes allow for gas to escpae easier, leaving the rotors cooler, not letting them warp or allowing brake dust deposits to form. And the slotted lines allow for more gas to escape and allow the brake pads to 'dig in' more to the rotor. I bought a set for all four of my wheels on my 94' cutlass supreme. They brake a hell of a lot better, but they are quite expensive.

JerryLH3

iTrader: (11)

Pretty good. They were brand new so no problems there. The Raybestos ones were about $60 a rotor. Only thing different is the rear rotors lacked three threaded holes - two for the screws and one to back the rotor off if it becomes stuck to the hub. They only had two holes. So you can just not use the screws and line up the rotor so one of the holes isn't matched with a tap in the hub.

Next time I'll probably go with Brembo on the front, just because they're about $10 cheaper through Tire Rack.

marcus219

Pads will last a bit longer too, due to less heat.

Warehouse

Yes in braking you are turning all the energy into heat energy... That is the whole idea behind a brake.

By adding holes and slots it isn't making the brake rotor that much more inefficient. You wouldn't be able to measure it.

You add these holes and slots to disipate the heat. Thereby increasing your ability to brake. By not having the excess heat of regular rotor your pads stay cooler. Thereby increasing your ability to turn the energy to heat energy. Also thereby decreasing brake fade when in a situation where there is a lot of braking involved (auto-x).

The loss in friction is minimal and isn't there for looks. Why look at a F1 car. See those holes? Also if you wanted holes it probably be worth it to go to a split rotor system.

Just thought I would clear the air...