The Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers perfectly. By upgrading your brakes with lightweight high performance replacements as opposed to a big brake kit, your factory bias is maintained as well as your ABS efficiency. The Girodisc front rotors are approx 13.2 lbs. vs. 15 lbs. for the stock units. This reduction in rotational and unsprung weight allows for quicker acceleration and suspension response.