RAC brake discs consist of an extremely warp-resistant, hardened and tempered steel. A special surface grinding process prevents any vibration occurring and thus improves the alignment of the brake pads (tolerance less than 1/100 mm). The even build up and dissipation of heat allows constant pad pressure. The electroplated surface protects against corrosion and the specific mix of materials increases the durability by 30%. The laser technology used in manufacture makes possible a lightweight design with finely engineered contours. RAC Brake Disc with FloatingDiscSystem. With all the advantages of the RAC brake discs, the innovative construction of the FloatingDiscSystem provides an effective solution to familiar brake problems as a result of warped brake discs. Because of the “floating” outer ring the pads make optimal contact with the disc. In developing the new RAC brake discs further, TRW Lucas has refined the strengths of the proven RAC discs once again and combined perfect braking performance with a unique appearance. For the rear brake, we recommend the normal RAC brake disc. ABE approved.