Help with Displacement maps

Greetings,
I am relatively new to 3D modeling, and animation.
Recently I put together a base mesh using Maya 11, exported that to Z Brush to sculpt the hi res details.
This is a model I plan to animate, so I brought it back into Maya as a very low poly model consisting of 1,476 polys.
Now I am trying to get the displacement map that I generated in ZBrush to show up in Maya.

The problem is that , the geometry is not being displaced as much as I had hoped. There are very few details showing up when compared to the zbrush model. I will include some jpegs to show some examples.

Few things I have encountered..
1: If I try to create a subdivision approximation and the try and do a test render on the model, the render shows up black.
- This lead me to believe that there is an issue with geometry, and so instead I tried a displacement approximation, which seems to work ok..
- my setting for the Displacement approximation are as follows:
method-spatial
style-fine
Min Sub Divisions-0
Max Sub Div- 1
Length- .025
The displacement map settings are:
Alpha gain-.050
Offset- .0
Filter type is set to off and alpha is luminance is checked.
Can anyone please offer some advice to what else I might try in order to get more detail out of my displacement map, or what settings I can tweak?
Anything would be great.
Thanks
Dan

Well , try to bake your normals with XNormals , also you have to put it to Bump map slot , you gonna need also specular maps . So all I can say check this tutorial :

Check this tutorial : http://www.game-artist.net/forums/spotlight-articles/42-tutorial-hard-surface-texture-painting.html

And you can check this one also : http://www.game-artist.net/forums/vbarticles.php?do=article&articleid=16 but that''s not exactly what I suggest .