I know that i know this, but im at a loss for it right now. id like to constrain a specific Fractured piece to another object in the sim but im not sure how to find the specific voronoi piece number to start going about this, unless there is another way to do this im missing? can some one kick me in the right direction?

There are many ways to do this.

1) In DOPs, you can view the objnames by turning on the ‘Object names’ in the viewport's display options. Just hit ‘d’ in the viewport.

2) In SOPs, you can view set a custom attribute display called ‘name’ from the prim attribute that comes from the voronoi fracture SOP. This will show you the name for each primitive. Kinda hard to read, but better than nothing!

3) Put down a delete SOP and cycle through all the ‘piece*’ groups. Cumbersome, but you can isolate the pieces easily this way.

In all non-DOPs methods, it's easiest to put down an ‘Exploded View’ SOP to separate the pieces out.

Perfect, thank you!

im still having trouble having a piece perfectly follow another piece as if its stuck to it, im using a pin constraint with the parent constraint modifier thing and its kinda working but the piece still slips away a bit, any idea how to keep it perfectly aligned to another piece?

If you want it perfectly attached to the other piece without any further sim, you can do it in SOPs. Make sure the ‘replacing’ piece has the same ‘name’ attribute as the ‘replaced’ piece. Same goes if you're using the ‘groups’ instead of names. Then, wire the ‘replacing’ piece into a DOP Import SOP. It should pick up the same position as the ‘replaced’ piece.