Vbulletin Search module is not so great (When people are mostly accustomed to very effective search engine by Google).

So, from a user perspective, below's a simple tip on how to effectively search in Vbulletin Forums
  • When searching for Multi-Word keywords, Include the whole phrase within quotes. Using keywords within quotes yields results you want.
    For example, "PI Industries" search yields better results than just searching for PI Industries

From a Vbulletin admin perspective, you can do a few things to optimize search results.
  • Go to Admin -> Options and fine tune settings in "Message Search Relevance options". After making modifications, rebuild search index under Maintenance in admin console.