After a server glitch caused an unexpected delay, Firefox 3′s Download Day is roaring off to an impressive start.

Mozilla now says it’s averaging 14,000 downloads per minute of the new revamped browser, which comes out to 13 gigs a second — whew! Engineers predict a download total in the tens of millions by the end of the first 24 hours.

The hope is to score enough total transfers to get into the Guinness Book of World Records for the most downloads of a single program in a single day — a task that looked unlikely for a while this morning. The record attempt ends at 2:16 p.m. Eastern Wednesday.