Oh I see. Don't use Varispeed! It's designed to be more a "preview" mode for a whole project rather than anything better IMHO.
There's many ways to change the tempo of an audio file in Logic. You could turn the audio regions into Apple Loops or...
- Change the tempo of the project to the desired tempo (e.g. audio and project was at 130, change project tempo to 138)
- Backup the original file (in the Audio Bin, select the file and choose Audio File > Backup File(s)
- Select the region you want to process and In the Arrange area's local menu choose Audio > Time Stretch Algorithm - choose an algorithm (start with Universal)
- Option-drag the lower right corner to time stretch the region to fit to the new tempo.
You can undo these changes and try the different algorithms - but remember this time stretching process is destructive so do backup your files first.
Hope this helps