1. Enable Dimensions for wildcard search by opening the project in Developer Studio, then open the Dimensions from the Project menu and you will see a button up top called "Configure Search". Open this and check the "Enable for wildcard search checkbox in the dialog box. You must re-run the baseline update.
2. Ensure that you are encapsulating the search term(s) inside the asterisk symbol when submitting the search to the Endeca engine. I can't remember but this may already be in the typahead.xq module.