You can enable more logging by going to the Web.config file and uncommenting out the section on trace listeners:
<listeners>
<!--
<add name="eventLogListener"
type="System.Diagnostics.EventLogTraceListener"
initializeData="SpiraTest"/>
<add name="fileListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="C:\Program Files\SpiraTest\SpiraTest_Trace.log"/>
-->
</listeners>
You need to uncomment the previous section and specify a real file location that you want the trace log file written to. Then you can change the logging levels themselves by changing:
<add name="generalSwitch" value="1" />
<add name="queriesSwitch" value="1" />
to
<add name="generalSwitch" value="3" />
<add name="queriesSwitch" value="3" />