Move your oven rack to the lowest position, and then preheat your oven to 325 degrees f.
In a large mixing bowl, whisk your cake flour, salt, baking powder, and sugar.
Slowy, add your lemon juice, grated lemon, water, vegetable oil, and egg yolks; mixed until combine using an electric mixer
Clean mixer whisks for the next step (below).
In a separate bowl, beat your egg whites, and cream of tartar until soft white peaks form.
Slowly fold in your egg whites into your batter
Pour mixture into an ungreased fluted tube pan and bake for 50-55 mins or until the top of the cake gently springs back when pressed.
Once cake comes out of the oven, gently press around the edges with a plastic knife to loosen it.
Allow the cake to cool for about 45 minutes before frosting.