SC here too. Track several times a year. In fact 64 events with the SC since 2003. Still OEM radiator, water pump, thermostat etc.
Though I have to confess that I intercepted the thermostat map cooling circuit so that I can open the stat earlier when needed, especially track in summer months.
Technik Engineering ASA Stage 1.
Supercharged E46 M54B25.
2011 NASA TTC So Cal Champion!
Technik Engineering oil cap o-ring maintenance kit available.