GrimmSpeed Catted J-Pipe/Downpipe | 2015+ Subaru WRX (0071XX)
Performance of the J-Pipe was verified on our 2015 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 retuned 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.
Our engineers began by 3D scanning the OEM J-Pipe and vehicle underbody using our in-house FARO Arm. That data was used in CAD to design a pipe that fits perfectly within the tight underbody packaging on a 2015 WRX without sacrificing ground clearance. The 2015 WRX uses a series of OEM brackets to support the weight of the turbo and J-pipe, the most important of which bolts to the turbine outlet flange. Our engineers insisted on using thick 1/2" stainless steel flanges, but also knew that without a clever design, the very important OEM brackets would no longer line up. The GrimmSpeed flange design uses a CNC machined pocket that the OEM bracket sits in during installation, allowing the use of 1/2" thick flanges as well as the factory turbo support bracket!
Finally, they worked tirelessly to design and manufacture a J-Pipe that could be bent from a single piece of tubing. This allows for more efficient manufacturing, less potential failure points and a product that fits perfectly each and every time.
- Innovative Turbo Flange Design (Patent Pending) 1/2" thick
- One-Piece Tube
- Smooth 3.5" to 3" Transition
- Optimized Tube Routing
- Custom Stainless Turbo Studs
- Standard 3rd O2 Bung
- Grounding Strap Mount
- 300 Cell Metallic Substrate Catalytic Convertor (Catted Models Only)
- Retains all OEM brackets
- Exact fitment, robust construction and ease of installation
- Matches turbine outlet size and then reduces quickly to maintain exhaust velocity
- 100% Made in the USA - Manufactured in Minnesota
- Maximizes ground clearance and minimizes flow restriction without modifying suspension hardware, etc
- Replaces the terrible OEM studs and nuts with these, machined specifically for use with 2015 WRX turbine outlet and our 1/2" flanges
- Allows the future use of aftermarket sensors
- Retains all factory functionality
Please Note: Fits Manual Transmission Only at this time.
- 2015-2016 Subaru WRX
What's in the box?
- 1 Welded J-Pipe Assembly
- 1 GrimmSpeed Stainless MLS Turbo to J-Pipe Gasket
- 1 GrimmSpeed Stainless MLS J-Pipe to Catback Gasket
- 4 Stainless turbo studs w/ nuts
- 2 Replacement catback bolts w/ nuts
- 1 O2 Sensor Plug (plugs third O2 bung for future use)
- 1 Grounding Strap Bolt (not pictured)
- 2 GrimmSpeed License Plate Frames
- 1 GrimmSpeed Sticker
- Grimmspeed Lifetime Warranty
THIS PART MAY NOT BE USED IN VEHICLES USING PUBLIC HIGHWAYS. THIS PART IS FOR USE ONLY IN COMPETITION RACING VEHICLES. ANY USE OF THIS PART IN ANY OTHER VEHICLE OR FOR ANY OTHER PURPOSE MAY SUBJECT YOU TO FINES AND PENALTIES FOR VIOLATION OF FEDERAL AND/OR STATE LAW, WILL VOID ANY WARRANTY FROM MODERN AUTOMOTIVE PERFORMANCE AND MAY VOID YOUR VEHICLE'S WARRANTY.
It is your responsibility to comply with all applicable federal, state and/or local laws relating to the use of this part. Modern Automotive Performance hereby makes no representation or warranty as to the compliance of this part with federal, state and/or laws and disclaims any liability resulting from the failure to use this part in compliance with all applicable federal, state and/or local laws.
First thing's first: If you've never taken the stock j-pipe off your WRX, get access to a lift. Breaking the 4 nuts loose on the turbo was the worst part of the install and I thought a few times that it would've been almost impossible to get the leverage necessary with the car on ramps or jack stands. Once that was done, the install was a breeze! Form and fit are perfect - everything lined up exactly where it should. GS includes all of the necessary hardware, even new studs (if needed). I also installed the Grimmspeed Resonated Catback Exhaust at the same time. After flashing the map, the car performs exactly where I feel it should now. No more hesitation/skittish feel with light pedal. Full pedal feels like a rocket booster has been attached to the car. With the full GS turbo back installed, it now has a nice, deep rumble to it - low revs are perfectly acceptable in almost any environment and won't piss off the neighbors. Full throttle sounds like a perfectly tuned, professional racer. Highly recommended. Worth every penny.
Grimmspeed makes some of my favorite mods and MAPerformance always the best service. If you're looking for this part but have not yet bought an Accessport with the Stage 1 OTS MAP tune you're doing it wrong. Buy and AP, then do your exhaust...I bought this before MAP had their Stage 2 Kit and although I can not comment on the MAP exhaust I suggest others look into the complete kit as it may be easier and cheaper.