1957 Chevy Dyno Tests Electronic Exhaust Cutouts- Loud Rules! Photo Gallery
The guys at GM Performance Division built the exhaust system for Project X to incorporate the Quick Time Performance (QTP) cutouts. They gave the exhaust a direct path though the cutouts when they are open and a route thought the pipes and mufflers when they're closed. QTP can supply you with a Y-pipe to incorporate into your existing system as well.