McLaren MP4 -23 - brake cooling drum development 02 November 2008
Introduced a few races back and used again in Brazil is this evolution of McLaren's brake cooling drums. Previously the drums were open, with the brake disc not included within the carbon fibre cover, leaving the edge of the disc and its outer face open to the inducted airflow. Now the drum assembly has been completely changed, following a trend common to Ferrari and BMW Sauber. The closed drum reduces aero disruption, but does tend to increase the working temperature of the brake assembly, including the disc, pads and calliper. This increases the tendency for the front wheels to lock under heavy braking - noticeable in Brazil, where Hamilton flat-spotted a tyre in Friday's second session. McLaren have changed the material in the coupling between disc and pads, but it's not clear whether concerns have completely disappeared.