Want to add new data to my recently submitted paper
As long as your paper is under revision, you can improve things.  Those improvements are not limited to those suggested by the reviewers, however:


The improvements should not change the nature of the paper too much, or you will annoy editor and reviewers.  Make sure they haven't wasted their time by reading the first edition.
Make clear that you have made this addition.  Some reviewers may only look at alterations based on their own recommendations, rather than re-reading the whole paper from start to end.


Once your paper is accepted, you can no longer add new data, text, or figures.