Spoon Sports B-Series 4-2-1 Exhaust Manifold (Header)4 2 1 design. Includes all required hardware. Developed in response to demand for a balance between peak power and torque. Spoon implemented various combinations of pipe diameter, assembly rotation, and other similar factors in exhaustive engine bench, flow bench, and actual driving tests. The power and torque were successfully balanced and using slightly uneven lengths for pipes, further reducing considerable weight.