Is there a way to add a code so that members can automatically go up a rank for posting enough?

This can easily be done by going to..
Admin Panel > Users & Groups > Ranks > Rank Administration

Choose 'Add new rank', Fill in your rank title, make sure 'Set as Special Rank' is set to 'no', fill in the 'Minimum Posts' field(ex: 1; User will attain this rank for reaching 1 post), then click save.

After that you can repeat these steps creating more ranks, and when a user reaches the amount of posts you've specified they will achieve that ranking.

Are you sure? I tried that once and it didn't work :\

It works perfectly fine for my forum. I do not need to constantly change members ranks for achieving post counts. On signup they receive the default(0 posts) rank of 'new member', once they achieve 10 posts they're upgraded automatically to 'member' without me ever having to edit their profiles.

I can confirm, it shall work

it will work.. i use also that way in my forum.. changing rank according to number of post..

Hm, well okay thanks! I dunno want went wrong then, but oh well.