my first program for real Instrument Clusters (BMW e36 tested) is ready for you.
The program used to operate a speedometer in a very simple manner.
Arduino connect with tachometer according to the instructions and connect in the program.
It may still 2 pots and 2 switches are configured as an input device.
Rpm, Speed, kmh, Gear and Temp as Output
2 x Poti, 2 buttons as input (handbrake, horn ...)
video show last test with rcc and Project Cars. Assetto Corsa and R3E work also
add support for R3e