Vehicle body takes lot of stress and lateral load under cornering. Rear Frame brace adds stiffness to the rear part of the body to prevent body torsion. Rear Body strength improves stability at the exit of the corner to the acceleration and prevent tail end to lose traction.
Not only keeps higher rigidity of the parts, but also keeps lower weights.
Okuyama uses oval shape pipe (20mm x 40mm dia.)for better torsion rigidity.