CSF Racing Race-Spec Dual-Pass Charge-Air-CoolerF8X M3 M4 M2 Comp Top Mount Charge Air Cooler Crinkle Black Finish The S55 suffers heavily from heat soak. Many tuners witnessed this early on after doing multiple dyno pulls and seeing significant drops in power after each consecutive pass. Many F8X owners experienced the same loss of power on the track as the engine just could not cool off during laps. The solution is two fold: The Charge Air Cooler (CSF #8082 8082R) & Front Mount Heat Exchanger