I bought a used 2005 g35 a few weeks ago and after taking out the clutch delay spring the clutch became rough at the top of the press. The higher the rpms the rougher it gets and when the car is cold I can feel it less. I can also feel a light tapping when I set my foot on the clutch pedal in neutral, and the tapping gets faster if I give it some gas.

I've been searching for an answer but I can't find a clear one, I'm guessing it's the throwout bearing but I get no noise and the clutch doesn't feel rough when the clutch is disengaged.