Message Searching Relevance Options (vBulletin Internal Search) - Rebuild Required?
 

I am using vBulletin search and trying to set things up so that threads with both my search terms in the thread title appears before threads that only have 1 or neither of the two. I have set the following values:

Search Relevance Multi-Word Match Bonus Score: 15
Search Relevance Date Score: 5
Search Relevance Thread Title Score: 10

and the rest are at default values, yet, it continues to rank the results in chronological order, ignoring whether or not any of the keywords are in the thread title. Do I need to rebuild the search index after making these changes in order for them to take effect? I have search result sharing disabled right now so I know I'm not getting old results.
thanks in advance.