I recently launched a tool called HN+
It's a tool where you can create your own HackerNews clone. Obviously, while working on this, I had to emulate the HN ranking algorithm. But what I found is that the algorithm actually doesn't seem to work well for a "young" forums.
I had to tweak it so that on the frontpage, the posts that are more relatively recent rises to the top over older posts of higher votes. I know these are considered in the original algorithm, but I had to tweak it.
Which made me think that the algorithm should be considering the age of the community and also how active it is.