A quote is attributed to Enzo Ferrari, "what do you want big brakes for, they just slow you down."

Whether "il Commendatore" ever really expressed that sentiment or not, it has a core of truth. In any form of motorsport or racing, weight is the enemy. It takes more power to accelerate a heavier car, heavier cars steer and take corners slower, and require more time or bigger (heavier) brakes to slow down.  Stripping off extra weight makes a car quicker and more agile.  Race classes have minimum weight rules to equalize the field, and trying to dip below that amount without getting caught is a popular "cheat" for obvious reasons. Various weight-saving parts are used in any serious performance car such as lightweight wheels, carbon fiber or aluminum body panels, removal of insulation material, etc. This "diet plan" makes for a lighter and therefore faster and better-handling vehicle.

With most of the typical "big" brake kits, the mammoth calipers and oversize rotors can add a significant amount of weight, working against the weight reduction effort. Even more than just static weight, the oversize rotor which can often be as much as 10lbs heavier than the original rotor has an even greater effect as it is a rotating mass, the weight gain multiplied by the moment of inertia physics concept.

"Big" brakes really can slow you down... even when you don't want them to.

Wilwood's use of FEA (Finite Element Analysis) and high-tech forging (as opposed to simple casting) has changed how brake calipers are designed and built in such a way that class-leading strength and light weight can be shared benefits. Additionally, the use of aluminum center sections in the rotors and lighter but stronger steel bracketry contributes to the weight reduction.

A simple comparison demonstrates how the PBK alternative falls right into the list of performance parts that reduce weight. Depending on the application, the PBK is an easy way to lose an amazing 26lbs. of unsprung weight from the front of the car:

This kind of weight loss means not only less mass to accelerate (so the car is faster in the straights), but also less mass to turn and stop...all of which adds up to make your car faster!

* Floating rotor option saves an additional 3lbs per corner.