Wagner Tuning Radiator Kit BMW M3 M4 F80 F82 F83 S55 | AustraliaThe 3. 0L S55B30 twin turbo engine for BMW M3 M4 models is equipped with an indirect charge air cooling circuit. So the cooling of the charged air is not realized by the ambient air as cooling medium (as usual), but made with its own cooling water circuit. A reduction of the temperature of the cooling water is directly equated with an improved cooling performance of the charged air. This is exactly where the advantages of the WAGNERTUNING upgrade