Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 9x13 inch pan. Mix together the flour, baking powder, baking soda, salt and cinnamon. Set aside.
In a large bowl, mix sugar, oil, juice, and eggs. Beat in flour mixture. Stir in shredded carrots, chopped nuts and flaked coconut. Pour into prepared pan.
Bake in the preheated oven for 35 to 40 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.