I had the same problem often before .

I had the same problem often before. I never found a way. It is possible to only SHOW a part of your contacts, but inevitably they will all get synced. This is especially frustrating since Google automatically creates a new contact for every person on Google+ you follow and it doesn't delete it when you unfollow that person. So I got stuck with ~7k unused contacts. I have a ROMed HTC Desire and the Contacts app was taking too much memory, so I had to delete all these unused contacts myself. But as far as I know, this option is not available, you could suggest it as a feature to Google like I did. If you ever find out how to do it, update this question please :)