Hey, sorry that you didn't got any replies yet.
AFAIK the problem is the resistance in the motors itself so without swapping them out for better ones you can't change anything at all.
Such a swap out is highly complicated and I wouldn't recommend doing this to anyone! Buying a better wheel is just... The better way to go!
Anyway what might help you with your problem:
increase the general FFB! You will lose details and feeling about the grip level but that's not THAT important for drifting so crank it up and it should spin faster.
You also could activate the centering spring in the logitech profiler but that would only make the wheel spin faster into center position. But for drifting you need the wheel to spin as fast as possible into the position of the front tyres, not just to "center"...
For the FFB settings:
Profiler: overall strength to 100%. Spring and Damper set to whatever you like. Spring is inactive in AC and damper is only for around 0-5 kp/h.
Deactivate the centering spring!!
Then go into your AC settings. Put overall strength to 100% and the
minimum force to 0%!
Also put slips, road, kerbs, abs to 0-5% only so they don't "take away force for spinning".
Now you should feel that the center position is quite "dead". Press "+" on your NumPad until the wheel starts to shake slightly while going fast and straight. That's the maximum force you can produce with AC settings and profiler.
I hope that helps