S54 is factory plumbed and equipped for an oil cooler. The oil cooler flow is controlled by a spring loaded thermostat system. The system does not allow full flow when the oil is up to temperature. Instead it is intended to stop flow until termperature is reached. Overheating of engine oil can be experienced on the track under these conditions. The diverter allows maximum flow.
After care must be taken to ensure oil temperatures are high enough for the 8K+ (when tuned) RPM capabilities of the motor.
This kit is sourced from Bimmerworld.
For a normal M3 the effort is more complicated as the main belt, alternator and PS pump would need to be removed from the oil block. As well as the oil drained and cooler lines removed.
S54 rebuild
S54 swap
S54 Oil Filter Housing
S54 profile gasket
S54 main tensioner
S54 track modification
S54 oil cooler
Fuji XT-20 XF18-55