RBR H-shifter 3.0
RBR H-Shifter is a plugin developed by Racer_S (link), that enables the Logitech G27 and G25 wheels H pattern shifter.
Installation is quite simple.
1. Download the plugin.
2. Extract file shifter.dll to folder plugins in RBR installation folder.
3. Run the game, go to options>plugins>RBR Shifter and configure your shifter. After saving you are good to go.
4. You can also disable the game clutch assist in Options>Gears.