I've never encountered any delay on any forum previously.

What's the point - to try to make the board less useful? To cut down on posts? Then why have a posting board?

Why should I have to wait 6 MINUTES in between my posts?
I feel I am making contributions - but this is wasting my time.

Another lovely aspect of this is that when it gives the fabulous "There has been less than 360 seconds since your last post" it doesn't preserve the attempted post - so all the work that has gone into the post is lost.

Any way this can be removed?

What about simply banning posters who are a problem/spamming/whatever, rather than wasting the time of your members with an onerous system?