One of the most significant problems affecting the performance of coilovers is friction. As dampers are in action, the moving parts cause friction, and this friction causes the oil to heat up. This heat alters the viscosity of the oil, and this affects the performance of the dampers. BR series coilovers are designed to overcome this to help ensure optimal performance even during heavy use.
BC Racing use only the best quality oils, and this in itself helps to ensure the best possible performance. However, the high-performance of BR series coilovers also lies in their design. These units consist of a 46mm damper in a large 53mm damper body. This large damper body size gives the unit additional oil capacity, and this means that friction has less of an impact on the temperature of the oil. This helps to keep the oil cooler than it otherwise would be, meaning it can retain optimal performance.