!!!WARNING!!! Before editing any files you should always make a backup copy!

Read this greate guide which explains how to tune the Force Feedback effects.

There is a slight error in that guide:

[...]
To keep the process under control, start from a simple FFB setup.
I start from this setup, no vibrations, no damper, no friction, no tyre grip, 1.0 gain, 1.0 exponent.

FFB Effects Level="1"
FFB Gain="1.00000"
FFB steer force exponent="1.00000"
FFB steer force grip weight="0.00000"
FFB steer force grip factor="1.00000"
FFB steer friction coefficient="0.00000"
FFB steer friction saturation="1.00000"
FFB steer damper coefficient="0.00000"
FFB steer damper saturation="1.00000"
[...]

To actually go through that step by step guide, FFB Effects Level should be set to at least "2", otherwise the friction and damper effects will be disabled, no matter what you set the coefficient to, and you wont feel the changes.

Hint: In Race 07 and its expansion packs you can change the controller settings without restarting the program. You just need to edit the control set file in your UserData/ControlSet folder. After saving the file you just need to click the reload button in the Control Settings screen in the program.