Brake Setup

[Giorgio]

I'm due for new brakes, well, I will be once i trash them autocrossing in a few weeks. I was originally going to go with Zimmerman cross-drilled with Repco(or Axis or something) pads, but my brother(Bryson) said that a bunch of people run ebcs in the front and mintex in the rear with stock rotors. My dad said ebcs and stock rotors would definately shake. If any of you have any experience with this setup it would be awesome if you could give me feedback. And that would be cool if everyone could tell me their favorite setup or what they are running, thanks.

[MattM20]

i'm using ebc greens with stock rear rotors and slotted ATE front rotors which so far have been working really well for me. i also have a 25mm master cyl (<- very worthwhile upgrade) and SS lines.

[Giorgio]

Thanks for the feedback, I think that is what I am going to do, go with slotted front and stock rear. I think my dad will let me use ebc greens with slotted in the front.

[65Matt]

Cross-drilled rotors will develop cracks if you run them hard. You are really better off using solid rotors. Here's the tech:

From Wilwood
Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity.

Slots 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. Drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood has a large selection of drilled and slotted rotors for a wide range of applications.

From Stoptech
Discs that have been drilled through with a non-intersecting pattern of radial holes. The objects are to provide a number of paths to get rid of the boundary layer of out gassed volatiles and incandescent particles of friction material and to increase "bite" through the provision of many leading edges. The advent of carbon metallic friction materials with their increased temperatures and thermal shock characteristics ended the day of the drilled disc in professional racing. They are still seen (mainly as cosmetic items) on motorbikes and some road going sports cars. Typically in original equipment road car applications these holes are cast then finished machined to provide the best possible conditions by which to resist cracking in use. But they will crack eventually under the circumstances described in another section (see Cracking). Properly designed, drilled discs tend to operate cooler than non-drilled ventilated discs of the same design due the higher flow rates through the vents from the supplemental inlets and increased surface area in the hole. That's right, inlets. The flow is into the hole and out through the vent to the OD of the disc. If discs are to be drilled, the external edges of the holes must be chamfered (or, better yet, radiused) and should also be peened.

From Baer Brake Systems
What are the benefits to Crossdrilling, Slotting, and Zinc-Washing my rotors?
In years past, crossdrilling 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 “green pad fade” or “outgassing”. When it does occur, the driver still has a good firm brake pedal, but simply little or no friction. Since this normally happens only at temperatures witnessed in racing, this can be very exciting!

However, with today’s race pad technology, ‘outgassing’ is no longer much of a concern. When shopping for races pads, or even ultra-high performance road pads, look for the phrases, “dynamic surface treatment”, “race ready”, and/or, “pre-burnished”. When these or similar statements are made by the pad manufacturer, the pad in question will likely have little or no problem with ‘outgassing’. Ironically more pedestrian pads used on most streetcars will still exhibit ‘outgassing’, but only when used at temperatures normally only encountered on the racetrack.

Although crossdrilling and/or slotting will provide a welcome path to expend any gasses when and if they develop, it is primarily a visual enhancement behind today’s often wide-open wheel designs.

Crossdrilling offers the greatest gas relief pathway, but creates potential “stress risers” from which cracks can occur. Baer’s rotors are cast with crossdrilling in mind, from the material specified, to curved vanes, behind which the holes are placed to minimize potential crack migration. Slotted surfaces are what Baer recommends for track only use. Slotted only rotors are offered as an option for any of Baer’s offerings.

[Giorgio]

Thank you very much for that.
So you think solids are fine for autocrossing? If so, I would like to go with solid rotors and ebc greens, it's cheaper, but i have to see why my dad thinks they will shake. I guess I could just go stock all the way around, but I would like something that could stop my car a little better.

[nando]

ATE powerslots are barely more expensive than stock rotors and they will not crack. :)