Depends on how hard the new springs are and if you have bigger heavier wheels. I found that the RS-R's and 19's were too much for the stock dampers and it seemed to wallow when pushed. That's why I went for the Tokico D-Spec's.
Got 19" Nismo LMGT4 alloys and am considering these Ti2000 spring also, where did you get your kit from?
Bought mine from eBay. A company selling out Vegas way. I found him from eBay.com, i.e. the US site.