Red Bull Racing have been asked before the Canadian GP to change the design of their front brake cooling system following an FIA inspection on the parts. The FIA considers part of the cooling system an aerodynamic advantages, and hence declares it not in line with the regulations.
The contested item is a series of apertures in the wheel hub, a feature the team has run for several races and that is unique on the Red Bull RB8. Although the regulations permit any aerodynamic shape within a defined area on the inner side of the wheel for the purposes of the brake cooling ducts, German magazine AMuS has learned the FIA now clarifies that any air that is caught through these ducts should be used for cooling the brake calipers and discs only.
The governing body claims that the holes through the hub are an aerodynamic advantage that does not contribute to the cooling of the brakes.
Red Bull on the other hand argued that the sole purpose of these holes is to cool the brakes. While the disputed holes may mainly cool the central part of the upright, thermal conduction through the bearings, upright and the caliper attachments will also cause the brake system itself to be cooled.
The FIA deems this cooling effect marginal compared to the potential aerodynamic benefit, and has therefore required Red Bull to adapt the system, acting before another team could officially protest the system.