Designed for track and off-road use, Fabspeed's Long Tube Competition Headers with integral Side Muffler Bypass Pipes are designed to maximize the potential of the Porsche 991 GT3 / GT3 RS / 911 R engine by increasing exhaust flow from the engine cylinders straight into the exhaust system. This system is built to optimize engine power all throughout the powerband. When the first 991 GT3s landed on North American soil, our engineering team immediately got to work and developed a Race Header to maximize the performance of the track weapon. Our original medium tube modular header design was very successful, but we were looking for more power. Consequently, we were approached to enhance a GT3 RS and welcomed the opportunity to refine our long tube header design further. After extensive development, including dyno and track testing of various designs, we’ve uncovered the correct formula to unlock the maximum performance and exhaust flow from the Porsche 991 GT3 / GT3 RS / 911 R. There is no better designed and engineered race header system for the Porsche 991 GT3 / GT3 RS / 911 R available worldwide. POWER: We developed our headers to make power with and without an ECU Tune. While the hardware made significant gains alone, we found its full power potential was realized when combined with our proprietary tune. As tested on a GT3 RS, our Long Tube Competition Race Header System with ECU Tune adds 38 whp and 26 ft/lbs of torque at 7650 RPM. Further down the rev range, our Header System gives you major mid range grunt: 24 whp and 28 ft/lbs of torque at 4500 RPM. Without the ECU Tune, you can expect solid gains of 24 whp and 16 ft/lbs at 7650 RPM and 23 whp and 26 ft/lbs at 4500 RPM. BURNS STAINLESS COLLECTORS: Bringing our headers to an end are Burns Stainless Collectors which combine high flow and high velocity to increase and broaden an engine's torque curve. Our decision to utilize Burns Stainless slip on collectors was easy, their superior design and 30 years of proven performance in motorsport racing provided more than enough reasoning. Engineered with proprietary X-design parametric exhaust design computer program Completely hand finished inside for proper flow and maximum power gains Motorsport proven and adopted by NASCAR engine builders along with world champions in ALMS, FIA-GT, and Grand Am race teams OPTIMIZED SIDE MUFFLER BYPASS PIPES W/ HELICAL VALVES: To provide the ultimate track solution for the 991 GT3 / GT3 RS / 911 R, we are now utilizing premium Helical valves. We chose to use Helical Valves for their unprecedented quality - which have been proven by many OEM manufacturers such as Porsche themselves, McLaren, Ferrari, Lamborghini, and many more. Increased reliability - proven in racing and high volume OEM use High-temperature bearings at both ends of the butterfly spindle Cast stainless steel valve body with stiffening ribs for ultimate durability FEATURES: *Adds 24 whp and 28 ft-lbs of torque at 4500 RPM and 38 whp and 26 ft/lbs at 7650 RPM with ECU Tune *Increases throttle response and dramatically improves sports car sound *36lb weight decrease from the rear of the car for increased handling *CAD designed and incrementally Dynojet developed and tested for maximum performance gains *Simple bolt-on installation; easily removable and replaceable for emissions testing *Constructed from T304 stainless steel C.N.C. mandrel-bent tubing from our in-house Unison mandrel bender. *Hand TIG welded and back purged by skilled Fabspeed craftsmen *All Fabspeed performance products are backed by the Fabspeed Lifetime Limited Warranty Available now, here: http://www.fabspeed.com/porsche-991-gt3-gt3-rs-911-r-long-tube-competition-race-header-system/