If you are running RealDash on same computer with the game, see this post first:
Localhost connections on Windows 10
Otherwise make sure that device running RealDash is in same local network with the Game.
On RealDash
- Go to the ‘Garage’ and open the vehicle door.
- Tap the instrument cluster and select ‘Add’ on left menu to add new connection.
- Scroll to the bottom and select ‘Racing Simulator’.
- Select ‘Forza Horizon 4’ from the connection type list.
- Note the port and IP-Address in connection settings.
- Tap upper left corner ‘Done’ button.
- Exit the Garage
On Forza Horizon 4
- Open game Settings and select ‘Hud and Gameplay’.
- Set ‘Data Out’ to ON
- Data Out IP Address, set to address shown by RealDash connection settings.
- Data Out IP Port, set to same port as set to RealDash connection settings.