Catback Exhaust - 2015-2021 WRX, 2015-2018 STi
- Calculated at Checkout
The 2015-2021 WRX & 2015-2018 STi Catback from Nameless Performance follows a long line of exhaust R&D established by Nameless Performance over the last four years. Following closely in the footsteps of the '11-'14 WRX/STi Sedan Catback, with a number of improvements and changes to fit perfectly on your '15 WRX with the DIT engine or your '15 STi using the tried and true standard EJ series engine. In testing on the EJ series engine, this catback has shown midrange gains of +32ft lb of torque and +22hp at the wheels above and beyond a standard off-the-shelf Stage 1 tune. That standard is achieved through a number of innovative design cues that have made Nameless Performance the top name in Subaru aftermarket exhaust development and engineering.
The main functional elements of this catback exhaust are its matched flow dynamic from the 3" diameter resonated main circuit into the 2" diameter secondary circuits (the dual circuits of the rear of the exhaust). Starting from a goal of matching the flow of exhaust through the 3" section and into the 2" sections, the division of exhaust is accomplished with a larger diameter 2.25" Y section in the midpipe, which takes the position of highest friction in the catback exhaust and ensures a proper division of exhaust gas flow without inducing restriction. Many other companies go oversized on the rear circuits to accomplish this goal of keeping flow up in a divided exhaust, however, the overall midrange torque suffers and the horsepower is no higher than a system with a smaller terminal circuit diameter. Our system on the other hand, produces more torque through the midrange than most exhausts on the market, while retaining higher than average horsepower gains. The result is a catback exhaust that makes a substantial difference in the behavior of the vehicle.
The second major advantage to the 2" dual rear circuits on the exhaust is a substantial decrease in low frequency cabin noise at cruise, often referred to as 'exhaust drone.' While larger rear circuit exhausts produce low frequency tones at lower flow dynamics, resulting in a boomy sound at cruise and an overly loud raspy sound at wide open throttle, our system produces a substantial reduction in cabin resonance while retaining an aggressive tone at wide open throttle.
The system is designed using 100% T304 (low corrosion, high strength) stainless steel throughout. From the flanges to the tubing and hangers to the perforated tubing in the mufflers, all of the stainless we use is the highest grade T304. Muffler packing consists of medium density, high temperature resistant ceramic wool, ensuring long muffler life and a compact lightweight design that muffles better than many market standard mufflers that are 3-4x the size of our in-house fabricated and engineered mufflers.
All weld joints are hand TIG welded by skilled craftsmen in our shop in the Pacific Northwest. With over 40 years of experience in the welding industry, our team is comprised of fabricators who have worked in every industry from automotive to heavy industrial fabrication. They pride themselves on their work and produce results that are unparalleled in the industry. Each of the connections in the catback are attached with latch over v-band clamp assemblies where they are not connected at factory connection points. At the front, a conical flare joint with a floating flange and a proprietary 3" donut gasket connect the catback directly to a factory downpipe or an aftermarket downpipe with a connection that gives all of the compliance of the factory system and allows easy adjustment during installation. At the rear of the midpipe, factory fit flanges are used with a larger diameter bore than the factory system that can still use factory gaskets (which are larger than the factory exhaust system). Factory OEM Subaru gaskets and all hardware are included with the kit.
- Muffler Delete: The loudest option. Removes the mufflers entirely. This is a 10 on a scale where stock = 0
- 4" Mufflers: Similar to the deletes, but with the edge taken off. This is a 7 on a scale where stock = 0
- 5" Mufflers: Our most quiet option. Perfect for those looking for a subtle upgrade. This is a 5 on a scale where stock = 0
- 3" Double Wall: These are T304 stainless, staggered double wall polished tips that fit perfectly into the cutout in the rear valence of the vehicle. 10 Degree Angle Cut with staggered arrangement (inboard tips stick out 1/2" further than outboard tips). 3″ diameter per tip, very close to an OEM look
- 3.5" Single Wall: Staggered ingle Wall Quad Tips in 3.5" diameter w/ 20 degree angle cut with a 1/2" staggered arrangement.
- 3.5" Neochrome Single Wall: Same as above but with blue flame/burnt tips fit perfectly into the cutout in the rear valence of the vehicle. 3.5" tip with a 10 Degree Angle Cut with staggered arrangement (inboard tips stick out 1/2″ further than outboard tips).
- 3.5" Double Wall: Staggered Double Wall 3.5" diameter quad tips, 1/2" staggered arrangement, straight cut, brushed finish.
- 4" Single Wall: Staggered single wall 4" diameter quad tips, 1/2" staggered arrangement, 10 degree slash cut.
- 4" Double Wall: Staggered double wall 4" diameter quad tips, 1/2" staggered arrangement, 10 degree slash cut.
Installation Guide - Axleback/Catback/Midpipe
Our urethane bushings hold your exhaust in place better that the factory rubber bushings and are highly recommended if you race your car or enjoy spirited driving. During hard cornering the exhaust "wags" left to right which sometimes causes the tips to touch the bumper. When this happens there is a chance your bumper can be damaged. The best way to avoid this is to use our urethane exhaust bushings to hold the exhaust in place.
- 2 Bushings: Replace the two bushings at the rear of the car closest to the bumper. Recommend for those who either drive hard on the street or race occasionally at the track.
- 4 Bushings: Replace all 4 rubber bushings on the axleback portion of the exhaust. Recommended for people who race their cars often.
- 5 Bushings: Replace all 5 of the factory rubber bushings on a Catback from the midpipe back. Recommended for those who are hard core autocrossers or circuit racers.