GrimmSpeed Catted Downpipe J-Pipe 2015-2021 WRX 6 Speed
Not CARB legal: Not for sale or street use in CA & CARB states
With the 2015-2021 J-Pipe, the devil is truly in the details and the product development team here at GrimmSpeed has taken the time necessary to knock each of those details out of the park. As a result, what you see here is a meticulously engineered J-Pipe with an innovative flange design, single-piece construction, excellent ground clearance, and fitment with superb quality and craftsmanship. The performance of the J-Pipe was verified on our 2015-2021 WRX using the following method. Our tuned baseline run is the same run that we used in showing the boost control performance of the GrimmSpeed 3-Port Solenoid. We then installed the J-Pipe and re-tuned the car, using the exact same tuning methodology to ensure consistency. This ensured a real apples-to-apples comparison between the stock J-Pipe and the GrimmSpeed unit. The results showed a gain of 26.7whp (14.1%) and 19.8wtq (9.0%) and are displayed in the chart to the left. The percentage gains should be the focus here, as this particular dyno reads very low (stock baseline was 171). From a completely stock vehicle, users can expect a gain of around 45whp (27%) and 70wtq (41%) with the installation of the GrimmSpeed J-Pipe and custom tuning. The chart on the right shows this comparison.
- This is a one-piece tube with Grimmspeed’s patented turbo flange design. This flange is ½” thick while retaining all OEM brackets.
- Provides a smooth 3.5 to 3” transition from the turbine outlet to the rest of the pipe.
- Excellent ground clearance without having to alter suspension components.
- Custom stainless turbo studs to accommodate the Grimmspeed ½” flanges.
- Standard 3rd O2 bung for use of aftermarket sensors.
- 300 Cell Metallic Substrate Catalytic Converter. Provides an excellent balance of reduced restriction of a ‘race cat’ compared to a 200 cell unit.
- 1 x Welded J-Pipe Assembly
- 1 x GrimmSpeed Stainless MLS Turbo to J-Pipe Gasket
- 1 x GrimmSpeed Stainless MLS J-Pipe to cat-back Gasket
- 4 x Stainless turbo studs w/ nuts
- 2 x Replacement cat-back bolts w/ nuts
- 1 x O2 Sensor Plug (plugs third O2 bung for future use)
- 1 x Grounding Strap Bolt (not pictured)
- 2 x GrimmSpeed License Plate Frames
- 1 x GrimmSpeed Sticker
2015-2021 WRX (6 Speed ONLY)