3k rpm vibration

[spongebob]

Hi everybody

Just did what everybody told me not to do, bought the cheapest Boxter I could find. (whithout PPC).
So far everything is working great and I'm still smilin as a child.
But... at 2800 to 3000 rpm there is a bad vibration in my engine, especially when I depress the pedal.
Can it be something whith the variocamsystem.I do not know at which rpm the camshafts change height.
The engine runs great at 6500 rpm so it should not be worn out. Or can a worn clutch make this problem.
If you recognize this please let me know.
And more questions: The best mechanic in SoCal, where can I find him (her)

Magnus