Dyno tests show Sinister Diesel’s Y-Pipes for the 2003-2007 6.0L Power Stroke Super Duty and Excursion add 65hp and 148 ft/lbs. of torque over stock at 2,300 rpm, improving drivability and towing capability. When installed with a performance tune it adds up to 121hp and 289 ft/lbs. of torque.
Sinister has replaced the bellows in favor of a stronger, longer-lasting “double slip” flex joint, allowing the Y-Pipe to flex and move during heat expansion while maintaining a 100 percent seal. Plus, Sinister Y-Pipes are fully TIG-welded, as well as back-purged. The Y-Pipes are available in raw, ceramic, and heat-wrapped finishes. (888-967-8823/www.sinisterdiesel.com)