Well at least a transfer rate of 20,000 bytes per second is not very much, nor
is 2 simultaneous connections. Try 0 for unlimited and 8. If the site is local
you could try increasing the number of connections even further if the http
daemon you are using allows it.

But ultimately the answer can only be had by looking at what it is downloaded
and how. Are you sure your javascripts are not broken or do not function in a
way that produces dynamic content (=site could be downloaded for eternity
because every dynamic link is "new").

Put "create log files" for "debug" and see them.