This Wilwood front big-brake hat kit uses a 12.88-inch rotor and the forged Narrow Superlite 6R six-piston caliper, the platform 140-9107 Black Calipers 12.88-inch Rotors Slotted Rotors belongs to. Choosing this over the stock front brakes gets you six pistons clamping a larger rotor, which gives a more consistent pedal and better resistance to fade on repeated hard stops at autocross or track days. Wilwood's description says the caliper's unsurpassed braking capacity is the base of the kit, and the kit is designed for all 1994 to 2004 Mustangs, including the V6, GT, Bullitt, Mach 1 and SVT Cobra models. Owners searching for a 94-04 Mustang big brake kit, SN95 six-piston front upgrade, or Superlite 6R 5-lug front setup will find this is the black-caliper, slotted-rotor version.
Before ordering, confirm the parts that the kit does not handle on its own. The manufacturer's note says a 15/16" bore master cylinder is recommended for proper brake function when installing this brake kit with the factory brake pedal and vacuum booster. The manufacturer adds that using the OE 1.12" bore master cylinder is not recommended and will require very high pedal effort to stop the vehicle. Wilwood's own listing also says the kit will require aftermarket wheel spacers of 3/16" (not included in kit) for front kit installation with OE wheels.
According to the manufacturer's variant chart, 140-9107 has black calipers with slotted rotors. The -D version adds drilled and slotted rotors, the -R version has red calipers with slotted rotors, and the -DR version has red calipers with drilled and slotted rotors.
The manufacturer recommends a 15/16" bore master cylinder when the kit is used with the factory brake pedal and vacuum booster. It advises against keeping the OE 1.12" bore unit, which it says requires very high pedal effort. Wilwood offers a 15/16" bore tandem master cylinder, part 260-18184, for this application.
The manufacturer notes that front installation with OE wheels requires 3/16" aftermarket wheel spacers, which are not included in the kit. Confirm wheel clearance against the manufacturer's wheel clearance diagram before installing.
The manufacturer publishes an assembly sheet for the 1994-2004 Mustang 5-lug, stock-offset Superlite 6R kit. It calls for installing the stock bolts from the near side and placing a 0.033-inch shim on each bolt between the bracket and the upright before tightening loosely. The hat must sit flush against the axle hub flange, or excessive rotor runout can result. The sheet specifies attaching the rotor to the hat with red Loctite 271 on the bolt threads, torqued to 155 in-lb in a criss-cross pattern, with optional safety wire per the manufacturer's data sheet DS-386. Check that the kit matches your model year spindle and that the hub stud pattern matches the hat before you start.
