Grease and lightly flour a 10-inch fluted tube pan. Set aside.
In a large bowl, beat together sugar and butter until light and fluffy. Add eggs, one at a time, beating well after each addition.
Beat in flour, 1 cup at a time. Beat in lemon-lime carbonated beverage and lemon extract. Pour into prepared pan.
Bake in 350 degree F oven for 60 to 65 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack for 10 minutes. Loosen side of cake; remove from pan. Cool. Makes 12 servings.