Hi Kevin,
Drum maps are a necessity when trying to do what you're doing with softsynths which do not follow standard GM drum mapping.
a Sonar Drum Map is simply a tool to map the input MIDI message (note number) to a different output MIDI message (note number) which will allow you to send a kick note on, for example only, note 27 and output it to note 32 for Superior Drummer.
Drum maps are extremely useful, but also tedious to edit and have not been updated since their inception.
toontrack has a users area where you can download drum maps already set up by users for EZD and Superior. log into your account there and go to the user area and you should find the drum maps you can download.
then you'll need to open the drum map window in sonar and load the drum map for EZD or Superior from the download you just did.
now, you'll need to verify that the input from the DT Explorer maps correctly to the output for Superior already in the map. you'll need to use your DT Explorer manual which should have the mapping for MIDI in it. verify each note going into the drum map corresponds to the correct sound you're expecting to hear, if not, you'll need to edit the drum map to show the correct input for the DT Explorer.
I have a tutorial on my website which deals with drum maps. I can't get to it from work, and I don't remember exactly which one it is. it's either:
http://www.beaglesound.com/EZD_Tutorial/EZD_Tutorial.htmor maybe it's
http://www.beaglesound.com/TTS-1/index.html