I'm have a drum track project with backing track from the original Project.
I have the original project tracks (*.Wav file) setup in a new directory. ( Re-Named to save time renaming them later in Splat) 
They are ready to import into the drum track project.
 
I need to keep the tempo and track time location in place as well.
I would like to Drag and drop from the browse but I don't know how relevant that would be.
I was working on this 2 weeks ago and when I imported the drum.wav files into the original project the drums did not line up with the rest of the project. Everything was recording with backing original project backing track in same tempo.
Maybe something to do with imported track wav files have no audio data at beginning? I have seen this with midi.
 
What is the best way to get this one?
 
Thanks

Is it possibly you accidentally made those WAV file groove clips ?
I would use the "Bounce to clips" function on all your exported files (Wave and midi)
 
A few other tips:
- Any tracks that have multiple clips in them, bounce them to 1 solid clip (using the Bounce to clips function)
- Make sure all your wave files start at 1:01. if need be, drag out the beginning and "Bounce to clips".
- Place a dummy notes at 1:01 on each individual midi track. then Bounce to clips. this helps with lining up your tracks
  correctly. Because by default Sonar begins/starts a Midi clips where the Data starts. not at 1:01.
 
If all this is done correctly, your project should follow tempo changes as you have made them in previous projects barring you have the tempo changes in the correct places.
 
 

Cool, Thanks for the help! :)
I'll give it a go!
 
Peace!