BimmerWorld DCT Thermostat Diverter Valve Kit - F8X M2/M3/M4
Thermostat bypass for unrestricted flow and cooler DCT temps
This machined aluminum block will open up the thermostat in the M2/M3/M4 DCT cooling system to be always open and flowing to the cooler. This replaces the brass internal valve and spring. The logic in the DCT programming will close the thermostat to manage temps. But in the interest of reliability, simplicity, and cooling we want this thermostat to always be open for track use. The last thing you want is for a thermostat to get stuck closed and overheat the DCT fluid and shut down your session. And with full flow the fluid is constantly circulating, getting more even cooling and avoiding heat soak.
Because cold fluid does not flow as well as warm, this piece is not recommended for cars that are driven in sub-freezing temperatures. In this case the factory logic makes sense - close the thermostat to get the fluid up to temp sooner. Also with this piece you will need to let the transmission get up to temp before heading on track (> 30°C / 86°F). A few minutes of idling should be sufficient.
F87 (19-21) > M2 Competition
F80 (15-19) > M3
F82 (15-21) > M4
F82 (15-21) > M4 GTS