Clutch cooling grooves for uniform plate temperature in friction launch

Clutch cooling grooves formed on a friction plate are provided. The grooves are shaped to provide for substantially uniform steel disk temperatures in friction launch of a vehicle. The grooves are shaped such that the largest cross-sectional area is located adjacent to what would otherwise have been a hot area on the steel disk and the smallest cross-sectional area is located at the coolest location on the steel disk, at the cooling fluid inlet. Thus, the groove is shaped such that the smallest cross-sectional area is located at the cooling fluid inlet, the largest cross-sectional area is located between the cooling fluid inlet and the cooling fluid outlet, and the cooling fluid outlet has a cross-sectional area larger than the cooling fluid inlet and smaller than the cross-sectional area adjacent to the hot spot of the steel disk, between the cooling fluid inlet and the cooling fluid outlet.