Megan Racing 2.5" Downpipe For R18 Owners (HF, LX, EX, EX-L trims) MSRP $195 Megan Racing Stainless Steel Down-pipes are made of the same high-quality T-304 that is utilized in our Headers and Turbo Manifolds for extreme durability and resistance to corrosion and cracking. The missing component between any Header/Manifold and your Cat-Back system, these Down-pipes will complete the high-flow exhaust system desired for the performance of your vehicle. With a noticeable power gain throughout the rev-range and a polished finish, these are a perfect addition for any performance vehicle. Expect an increase in exhaust tone, due to freeing up the exhaust flow and the deletion of the catalytic converter. (NOTE: For off-road use only, not intended for use on public highways.) Key Features: Significant power gains. High quality, 100% T-304 Stainless Steel. When necessary, Megan Racing uses stainless steel flex joints to help dampen the cat-back exhaust system from engine vibrations. Bolt-on installation. TIG-welded for strength and durability. Straight-through design and bolt-on installation. CNC-machined flanges for strong solid support and mandrel bent tubing. http://www.meganracing.com/product_detail.asp?prodid=1473&catid=10 ====== Ultimate Racing 3" Downpipe For SI Owners MSRP $399 Catless Unleash the potential of your big displacement K motor with our high flowing 3" Header Downpipe. This product eliminates BOTH OEM catalytic converters. Available Catless or with a single High Flow Cat! - 3-inch 304 stainless steel piping - 3/8" thick flanges - Cast stainless steel high flow bellmouth design - High quality stainless steel braided flex section with interlock liner - Available Catless, or with your choice of High Flow Cat - Bungs for OEM, as well as an additional, oxygen sensors included (plug provided) - Bolts directly to OEM catback exhaust location Ultimate Racing Dyno Sheet With 3" Catback Exhaust product link http://www.ultimate-racing.com/Products2/12-CivicSi/12-CivicSi_Header.shtml View: http://www.youtube.com/watch?v=2kPCmv6nR-c additional info/thread http://9thcivic.com/forum/threads/ultimate-racing-downpipe.5332/ ====== RV6 Performance 2.5" Downpipe For SI Owners MSRP $369.00 Catless RV6 Dyno Chart: View: http://www.youtube.com/watch?v=XwVUVd0NRh4 View: http://www.youtube.com/watch?v=7_Ito7AYkpQ http://rv6-p.com/civic-si/civicsi-9th-gen/civic-si12-downpipe-213.html 9thcivic info thread http://9thcivic.com/forum/threads/rv6-2012-civic-si-bellmouth-downpipe.5570/ ====== Skunk2 Alpha Series 3" Downpipe For SI Owners MSRP - $418.00 Header Design: This Skunk2 Alpha Series Race Header features a large 4 inch bellmouth design with 3 inch outlet is manufactured from high quality cast stainless steel for superior heat resistance and strength. This design enables maximum extraction of air flow and increased power. Heavy duty 1/2” thick flanges ensure secure and leak free attachments. Air flows smoothly through mandrel bent T-304 stainless steel and a high quality stainless steel braided flex section. The one piece design eliminates the need for the catalytic converter maximizing air flow and allowing for maximum power. Bungs are also included for the OEM O2 sensors. No modifications are needed as it is a direct bolt-on unit to the OEM exhaust cat-back location. Key Features: Large 4 inch Bellmouth Design Manufactured from High Quality Cast Stainless Steel Thick 1/2 inch Flanges T-304 Stainless Steel Construction Precision CNC Mandrel Bent High Quality 304 Stainless Steel Braided Flex Section One Piece Design Eliminating Catalytic Converter Acid-Etched Alpha Badge Bungs for OEM O2 Sensors Skunk2 Dyno With Downpipe & 76mm Exhaust Product Page http://store.skunk2.com/12-civic-si-alpha-series-header.html ====== Full-Race 3" Downpipe For SI Owners MSRP: $349.00 WhiteFG4 was the test vehicle The Full-Race Honda 9th Gen Civic Si 3" All-Motor Downpipe is available now! Designed to extract maximum power from naturally aspirated K24Z7 engines, our high flowing design delivers significant power and torque gains throughout the power band by reducing back pressure and increasing flow. Looking for the ultimate exhaust combination? Pair our the Full-Race All Motor Downpipe with the Full-Race 9th Gen Civic Si 3" Exhaust System for additional horsepower, torque and superior tune. Full-Race Honda 9th Gen Civic Si 3" All-Motor Downpipe Features: 304 stainless steel construction Mandrel bent, large radius bends Precision TIG welded and purged CNC'd oxygen sensor bungs "This is a YouTube video of the difference between normal exhaust and the catted downpipe/full exhaust." Product Page http://www.full-race.com/store/down...h-gen-civic-si-3-all-motor-downpipe-2012.html ====== .