does any body know if there are any special instructions for drilling stock rotors(if it can be done)? i know you need different kind of pads with drilled rotors cuz i got them on the front of my truck and i want the rear to match.

Well, I honestly wouldnt drill them myself. Im sure there is a lot that goes into drill the rotor, like placement, type of bit used, type of rotor, etc.

And I wasnt aware that cross drilled rotors required special brake pads. I dont see why it would be required for something like that.

On one hand, I've seen it done successfully, and on the other hand, I've also heard that your asking for big big trouble by drilling into the stock cast iron rotors. It makes sense to me that drilling introduces stress risers into an already brittle material. There's gotta be a way to do it, heck they sell the drilled rotors, but I don't know the proper way to do it, I think one thing for sure is to chamfer all the holes that you drill, get rid of the sharp edge. One bit of adivice if you do find a safe way to drill your own rotors... with the pattern that you drill out, aim to keep the area of contact with the pad constant, that is, don't drill all your holes along a line radially from the center to the outside, as the rotor turns, you'll go from full contact to minimum contact. You want to keep contact area roughly the same as it rotates. If you want a pic of what I'm trying to explain, let me know, I'll show you the rotors I designed for the FSAE car at UT.
Jason

I've seen some of the local honda guys do that... don't think they've had problems...

I don't think they look even close to a real drilled rotor...

Cody

i wasnt planning on drilling them myself. i was just wondering if it could be done at a machine shop. as for special pads with drilled rotors, i guess they are harder or somthin. when i got my powerstop drilled rotors at summit the dude said i needed these pads cuz the stock ones would wear out quickly. so i bought them. theyve been on my truck for 2 years and are hardly worn. i would like to buy new rotors for the back of my truck. but the rear end is out of a old linc. and i had to get the bolt pattern redrilled to match my new axles that where 4.5 on 5. the stock rotors where like 80.00$ for the set and the drilling is 40$. maybe i can find a set of new drilled rotors and get the pattern done again. thanks for the input.

Originally posted by jasonsmf
On one hand, I've seen it done successfully, and on the other hand, I've also heard that your asking for big big trouble by drilling into the stock cast iron rotors. It makes sense to me that drilling introduces stress risers into an already brittle material. There's gotta be a way to do it, heck they sell the drilled rotors, but I don't know the proper way to do it, I think one thing for sure is to chamfer all the holes that you drill, get rid of the sharp edge. One bit of adivice if you do find a safe way to drill your own rotors... with the pattern that you drill out, aim to keep the area of contact with the pad constant, that is, don't drill all your holes along a line radially from the center to the outside, as the rotor turns, you'll go from full contact to minimum contact. You want to keep contact area roughly the same as it rotates. If you want a pic of what I'm trying to explain, let me know, I'll show you the rotors I designed for the FSAE car at UT.
Jason
jason
i got the motor in the rear end in and half the front suspension in. ill have some pics soon

The problem with drilling your rotors your self is having them out of balance. It will cause vibration!!! As for pads softer pads (organic,cheap semi-metallic) will be used up faster on drilled rotors. Better to go with harder pads I recommend AXXIS METAL MASTER or a ceramic pad. I use a C & c Machine to drill and slot rotors. If you want some we are doing a group buy on our preferred vender board G.T. performance right now!

I do know that if you do not want you rotors to crack, you must have them ball mill drilled so that the holes are stressed relieved.


I think its not worth the effort.

Buy a set of anodized powerslot rotors. For $10 more each they have crossdrilled anodized rotors.

Mackintire

IN the gospel according to Carroll Smith he says: "don't do it"

slots in the surface are what works.

What you are doing is adding a channel for high temperature gases which "out gas" during heavy braking.
The gases, which are composed of vaporized liner material and vaporized resin material which hold the liner together, either collect between the pads and rotor, thereby reducing contact, or can be channeled out along the grooves.

btw: Unless you are road racing or pulling a trailer in the mountains and getting red hot rotors anything you do is for show.


The drilled holes in cast iron rotors are asking for stress cracks.
At least go to pre-drilled stainless steel rotors. Its more ductile and more likely to have been stress relieved AND properly balanced after the drilling/champering of the holes.

did i mention my rearend is a nine inch ford out of a 70'S linc that had the larger bolt pattern 5 on 5 i think not 4.5 on 5. so the guy who rebuilt my rearend redrilled a new bolt pattern 4.5on 5 in the stock rotors that came with the rearend. i would like to get new powerstop rotors but i would have to have them redrilled as well and i dont know if they even make them or not. but if it aint safe to drill or have them drilled(or sloted) i wont do it.

Why not just get some rotors for a 9" with the right bolt pattern. They are out there, because they make just about every bolt pattern parts for a 9" rear.