I want to make a chiffon cake without any orange or lemon flavoring.  I love the texture of Orange Glow Chiffon cake.  How would I modify the recipe to make it without the orange flavoring?  I noticed the lemon chiffon cake recipe uses baking soda while orange chiffon cake uses powder.  Which should I use?

You should use the baking powder version (orange).  If it were me, I’d use a vanilla bean or two for more flavor, and a flavored oil, like almond oil from la tourangelle.  You could use water in place of OJ, or try skim milk, but if trying skim milk consider making a test cake, as I haven’t tried it and don’t know how the dairy will affect the setting of the eggs.