help boxster 986 S steering judder knocking wobbling

[supermario]

hi guys

I've searched but can't find anything

hopefully someone can help or advise what might be wrong with my car

basically I'm getting alot of juddering/knocking through the steering wheel, and it seems to get worse the faster I go. I can visibly see my arms shaking with what the steering wheel is doing i.e. it seems to knock/jolt/judder left and right etc in a fast motion possibly in relation to what the wheels/suspension are having to cope with the roads/bumps etc but its making the car undriveable. Steering feedback I expect from a porsche but not to this level!!!

I'm running 18" turbo alloys with brand new conti n2's 225 front, 265 rear. I've tried balancing twice, and an alignment when the new tyres were fitted but no good, problem still remains.

Have i got a number of bad front suspension/steering components somewhere on the front end which would cause this shimmy?

my cars done 60,000 miles and is just over 8 years old.

Thanks in advance

supermario