Im currently using a Kh-202 ltd esp with a licinced floyd rose im using ernie ball top heavy bottom slinky strings tho i cant pull back on the floyd rose due to the strings being too tight for the springs i think i currently have 3springs and im in drop D tuning
If there's too much tension in the strings, either get lighter gauge strings, add more springs in the back, or tighten the screws in the back so the springs provide more tension. As to how many, I have no idea.

Experimentation is key here.
Quote by MopMaster
Experimentation is key here.

Listen to the man. The more tension you give to your whammy plate, the more stability you'll get from it if you can adjust it properly (unless you use dental floss-like strings). Try putting 4 springs and let the 5th slot be the middle one, that or put 5 springs in it, should keep you busy for a wahile adjusting all that though :P.

If you've got no idea on how to set-up such drastical changes to your guitar type floyd rose adjustment on google, floyd's official website should teach you all you'll need.
I love music, if music would be a girl then I'd date her, until then let's get back on Earth