Paper to Web Form Initiative - Slow Search

I developed an InfoPath form and site that supports a paper to web form initiative.  Right now there are 40 infopath forms on the site.  Each form has over 300 data points in it.  This causes search on this site to be very slow because it searches through all the data on each form.  This library will grow to well over 40 forms.  This is a long term solution, so eventually there will be hundreds of forms, and another library that will have an archive even larger than that.  How should I plan to scale my architecture so that the search doesn't take over 15 seconds.  Currently it takes about 20 seconds to run.  Ideally, I'd like to get this down as much as possible.  I'm still trying to understand how InfoPath information is stored, crawled, cached, etc.

Can somebody help me understand this, as well as how to scale to prepare?