When it comes to brake rotors, racers are constantly searching for the ultimate balance between the lowest weight and the ability to effectively manage heat. Decreased rotating weight in the drive line provides quicker deceleration under braking and quicker acceleration out of the corners. Lower weight also benefits handling with improved spring and shock control over the unsprung suspension mass. Wilwood's ULD-32 drilled iron rotors provides effective lightweight options for sprints, late models, modifieds, and other competition applications that race in low to medium temperature ranges.
- Cast from premium grade, long grain carbon iron
- Close tolerances on face and vane thickness
- 32 straight vane casting provides superior heat management and long service life
- Two row, 64 hole pattern - alternates between and directly over each vane
- Each hole deeply chamfered to eliminate stress points
- Rotating and unsprung rotor mass reduced by 12%
- Left or right hand mounting locations
Caution on Drilled Rotors
There is a common mis-perception that rotors are drilled to improve cooling. The reduced mass of a drilled rotor will dissipate its retained heat quicker, but it also builds up heat a much faster rate. The decision to use drilled rotors should be solely based on the merits of the lower rotating and unsprung weight, and NOT for improved cooling. It is NOT wise to use drilled rotors in sustained high heat on hard braking tracks unless the team budget affords a high frequency of rotor and brake pad replacement.
- Race drilled rotors are unsafe for street use
- Suitable applications: Light to moderate Dirt Racing
Proper Break-In Procedure for Steel or Cast Iron Rotors
New steel/iron rotors should be bedded in before being used in racing conditions. Proper bedding will prepare the rotor surface, prolong the rotor's life, and make it more resistant to thermal checking or cracking under severe braking conditions. The following procedures should be performed when bedding in both steel and cast iron rotors. It is best to bed in a new rotor using a used set of pads, preferably ones which will not create heat rapidly. Generating heat too rapidly will thermal shock the rotors. Likewise, when bedding in a new set of brake pads it is best to perform the process on a used rotor. This new/used bedding process permits controlled bedding of each individual component.
Make sure rotor surfaces are free from oils, grease, and brake fluid. Run vehicle up to a moderate speed and make several medium deceleration stops to heat up the rotor slowly. This will help reduce the chance of thermal shock caused by uneven heating of the rotor. Pull into the pits and allow the rotor to cool to ambient air temperature. Care should be taken not to ride the brakes into the pits as this may hot spot the rotor causing premature wear to the surface or structural damage.
- Vented iron
- Inboard mounted (Sprints)
- Thickness: 0.81"
- O.D.: 12.19"
- Bolt Circle: 8 x 7"
- Threads: Thru
- Weight: 8.6 lbs
- Face: drilled
- Rotor Mount Hole Size: .326"
- Lug ID / Registration: 6.38"
- Far Side Inside Diameter: 8.56"
0.81" x 12.19"
8 x 7.00" B.C.