FINELY crush 35 of the wafers. Place 4 Tbsp. of the butter in medium microwaveable bowl. Microwave on HIGH 1 min. or until melted. Add wafer crumbs and 2 Tbsp. of the sugar; mix well. Press crumb mixture firmly onto bottom and up side of 9-inch pie plate.
MIX 1 cup of the remaining sugar and the cornstarch in medium saucepan. Add egg yolks; mix well. Gradually add water, stirring until well blended. Bring to boil on medium heat, stirring constantly. Boil 1 min., stirring constantly. Remove from heat; stir in lime juice and remaining 1 Tbsp. butter; stir until butter is melted. Place wax paper on surface of hot filling; refrigerate until chilled.
PREHEAT oven to 350°F. Pour filling into crust; insert remaining 12 wafers around edge of pie. Beat egg whites in small bowl with electric mixer on high speed until frothy. Add cream of tartar; beat until soft peaks form. Gradually add remaining 1/4 cup sugar, beating until sugar is dissolved and stiff peaks form. Spoon meringue over filling; spread to edge of crust to seal.
BAKE 10 to 15 min. or until lightly browned. Cool on wire rack. Refrigerate at least 6 hours or overnight. Store leftover pie in refrigerator.
