Hello,
I see a lot of messages and workshop about how to set the ffb in game and with logitech profiler, but i find really good settings in a different way.

I only changed file named "devicesetup_v2"
path "C:\Program Files (x86)\Steam\steamapps\common\DiRT Rally\forcefeedback"

there is a part with wheel settings:
<!-- Wheels -->
<!-- SimSteering Wheel - Note: Recommend starting with a scaleForce of 0.5 until comfortable with the scale of the force -->
......
<!-- Logitech G25 -->
<FFBDevice name="{C299046D-0000-0000-0000-504944564944}" scaleFriction="2.55" scaleForce="1.25"/>
......

I changed scaleFriction from 1 to 2.55 (seems to be wheel weight/resistance) and scale force from 1 to 1.25 (seems to be effects).
And, noting in game and in logitech profiler (all default).

This work very wheel for me, tell me if this work also for you. Settings are probably different with other wheels than G25.