I just changed from old worn Continental SportContact 2 255/40 ZR17 to new Continental SportContact 3 255/40 ZR17.
I thought I should be happy now, but the rear end actually feels more loose now
I just participated in a slalom cup and have also had the car running at 90% of maximum topspeed without any panic on the old tyres.
But now I have an uneasy feeling just running 130 Km/h....
Are there a break in time for new tyres?
Has anybody else tried the third version of the sportcontact tyre?

 

New tires will have a lot of oil in them from the molds. They also have some excess rubber that needs to wear off. Newer tires have taller tread blocks as well. So yes there can be a bit of a break-in period. May also be some difference between the 2 and 3.

 

According to tests I have read, the 3 has less grip in the dry compared to the 2.

 

=> Devils_son: Do you have a link to any of the tests you've read?
It's not the grip that have worried me so far, but the woobly feeling at higher speeds.
So now I have to worries.
I'm going to the track next week, so I better start putting some miles in them...

 

Not a link, just have them on paper.

One other thing is that the problem you experience is due to the fact that you shouldn't mix-and-match different compounds on a 964. So maybe your car will behave better if you put SC3's on the front as well.

Apart from that: are your SC3's N-coded. Conti is known for having both a non-N coded as well as an N-coded tire whithin the same size and type...