cross drilled rotor install

[pintocrazy]

i was wondering if n e one could help me on this... i was told that to install cross drilled rotors i would have to get a whole new brake caliper setup and brake pads... n e feedback would b great.

[nialusa]

Thats BS, you can use your standard caliper and pads on a cross drilled disc as long as its the same dimensions as the standard one on you car.

[Brian R.]

Might want to spring for a new set of pads so that they break in on the new rotor.

[91 Celica St]

cross drilled rotars are usless...there a wast of money, they wont increase your stopping distance at all...get new break pads

[nialusa]

Originally Posted by 91 Celica St

cross drilled rotars are usless...there a wast of money, they wont increase your stopping distance at all...get new break pads

They wont "decrease" your stopping distance but they do aid with cooling quite well, which will help with brake fade when your discs get hot. better if you have big discs and a heavy car, not worth the expense on smaller discs/cars, go for slotted discs if anything.

[91 Celica St]

Dude, you're tech is about 40 years too old. Drilled holes in rotors and drums were useful when pad and shoe materials were less then ideal. When heated, they would expell gases which would not allow them to make contact with the rotor. So, holes allowed those gasses to escape. But, and this is a big but, new pads don't require this. They don't expel nearly as much gas and don't need cross drilling. So, the only purpose of this is too look cool and to cause stress cracks from uneven cooling. If you want, goto or check out Sears Point when they are having a road racing event. If you can show me one car there that uses cross drilled rotors I would be surprised. It's antique tech that just happens to look cool. Yes, I admit it. But, it does nothing for braking. If you want to learn anything about brakes, read this link. This is from a Nissan Altima site where a vendor gets taught a few things from some real mechanical engineers and people that actually race in series like Amerian Iron and American LeMans. Look for posts by MaddMatt and Jetengindoctor Cobra and slowSE-r and Jon-A. MaddMatt races for half the year and Jeteningdoctor is, well a jet engine doctor. He's a mecanical engineer.

http://corner-carvers.com/altimathread.php.html

[nialusa]

Taken from that site you linked to -

Crossdrilled rotors-by design, crossdrilled rotors were designed for track use. Why? Because, when you drill holes in your rotors, they are designed to dissipate heat. - Is that not what I said????

So why do the likes of Porsche, Aston Martin, Ferarri, TVR, High end Mercs, Nobel, all use drilled discs? I never said they decrease stopping distance.
They are there to cool the disc, not the pad, it helps to stop you from cooking your brake fluid through heat disapation.

[nialusa]

Also form the site you posted -
These stresses are what causes the cracking that you have seen in drilled rotors that have been subjected to extreme racing conditions. Similar cracking occurs on the surface of a non drilled rotor, but that cracking remains at the surface

[SigmaProjects]

Originally Posted by Brian R.

Might want to spring for a new set of pads so that they break in on the new rotor.

last time I remember you want to use some used brake pads to break in the rotors.

And I have to agree with nialusa. I put some x-drilled and slotted rotors on my celica (there's a good machine shop near by that does it for free whit purchasing new rotors) and it's for break fade. Ever drive a heavy vehicle shift down so you don't have to brake as much and then watch the idiots brake so much down hill and find out that their brakes are worn out? You should already know this CelicaSt. Have you seen how hot rotors can get? Like glowing hot?

http://www.rally.gr/data/photo-large/10736.jpg

A real race car with slotted rotors. There is your proof.

[Brian R.]

Originally Posted by SigmaProjects

last time I remember you want to use some used brake pads to break in the rotors.

You can do what you like, but that's not what I would do. New (turned) rotors, new pads. It's your money.

Drilled rotors probably don't cool any better than undrilled ones, but they do cut down on unsprung weight.

[91 Celica St]

Yes they do. But, they also reduce the amount of heat that the rotor is able to absorb which is what leads to brake fade. Think about this. The rotors main job is to absorb the heat created by the pads. Big Brake kits do this by adding mass to the rotor, ie going to larger diameter, thicker rotors. This allows repeated hard stops without cooking the brakes. When you remove mass from the rotors, ie crossdrilling, you reduce the heat absorbing properties of the rotor. So, it has less ability to absorb heat from the system which makes the rotors overheat faster. And then, as you stated the heat get dissipated by the "cooling holes." Which causes uneven cooling around the holes vs the rest of the rotor surface. This leads to cracks with repeated use. Some drilled rotors are better than others. Porsche actualy casts the holes in their rotors. This makes them a little more durable but, they will still crack before a solid rotor.

All rotors will crack with hard use. But, why do something that will make them more likely to crack? Crossdrilled rotors will crack before slotted rotors. And slotted rotors will crack before "regular" rotors. I personally only use regular rotors on my cars. Have you ever seen what happens when those tiny stress cracks get bigger? Can you say multi-piece rotor?

[91 Celica St]

and as i see in that pic SLOTTED rotars not drlled and slotted, the argument is that drilled and slotted rotars are usless and actaully decrease performance, find me a car that has them that is ACTAULLY a race car

[91 Celica St]

if drilled/ slotted rotars are so good at heat disipation and stopping distance then why dont cars suck as nascar or even smei trucks use them?

and im not just talking about drilled or slotted, the discussion is over drilled slotted rotors

nacar brakes

http://images.google.com/imgres?imgu...D%26ie%3DUTF-8

[nialusa]

Originally Posted by 91 Celica St

and im not just talking about drilled or slotted, the discussion is over drilled slotted rotors

Sorry I`m lost now???? are we talking "drilled and slotted" discs? or just "drilled" or just "slotted"???

[nialusa]

And fir every piccie you post of a car without drilled discs I can post one with, so its a pointless exercise really. both are used, both have there benefits and drawbacks.

http://www.maserati-alfieri.co.uk/al...cgrath-13a.jpg

http://www.spidertrax.com/brakes_cdr1.jpg

and a picture of a Lambo for good measure although you cant see the brakes.
http://www.sampogrupp.ee/Lamborghini_Premium_950_1.jpg