The JUN connecting rod is made by shaving in order to pursue lightness and strength, this form has no futility. The material of a connecting rod is used SCM440. And connecting rod bolts are made by ARP. If big end is transformed at the time of high rotation, a metal will burn. In order to prevent the phenomenon, it was made the form which distributes stress. The JUN SUPER CONNECTING ROD prevents the transformation at the time of high rotation by correcting the form of a big end and raising strength, and keeps clearance.