I'm a lifelong keyboard user - started when I got myself a ZX81, so that's 25+ years!
Tried using wheel, but I'm much faster with keyboard.
Keyboard Option Settings:
Stabilised
Steer Rate: 0.42
Return Rate: 0.18
Fast Speed Multiplier: 1.00
Slow Speed Multiplier: 0.00
Limit Multiplier: 0.75
Button Control Rate: 5.50
I have sometimes dropped my above Steer and Return rates to do Oval Racing, as it makes cornering much smoother, therefore quicker.
Find some of the cars understeer badly when using keyboard (especially FZR, FXR, XRR), so have to put lot of front wing on, and next to zero rear wing. Alter tyre pressures accordingly!
If you like racing with keyboard, stick with it. Quite a few very quick keyboarders out there (wish I was one of them!). Always nice to see them, especially on my server.