crack / good time
There is the common U.S. usage of "a cracking good time", but don't know if this is related to the Irish expression.

Incidentally, I believe that the use of the term "cracker" to denote a redneck, or uncouth person in general, is considerably more than mildly pejorative. In some circles, at least, it is as bad as the infamous "n....." word commonly used by crackers.