The Yoshimura R-77D Full System is a dual-outlet version of the race-proven R-77. It offers greater gains in low and mid-range power without restrictive inserts. The Yoshimura R-77D requires no inserts or restrictions, increasing muffler packing life and providing five percent more open exhaust outlet area and as much as three decibels lower sound output. (compared to the standard open R-77) Trapezoidal-shaped sleeve Large volume of packing material Straight baffle for ample flow Stainless steel header and tail-pipe