J-Pipe High Flow Downpipe for 2015-2021 Subaru WRX FA20 - 6MT Only
Unlock serious power from your FA20 WRX with this 3" J-Pipe and downpipe combo. Designed specifically for 2015-2021 Subaru WRX with 6-speed manual transmission. Replaces the restrictive factory J-Pipe and catalytic converter for massive turbo performance gains.
Performance Specs
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Diameter: 3" (76mm) mandrel-bent tubing
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Design: Catless J-Pipe and downpipe combo
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Material: T304 stainless steel
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Power Gains: 25-35 HP, 30-40 ft-lbs torque (with tune)
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Fitment: 6-speed manual transmission ONLY
What's Included
- 3" stainless steel J-Pipe
- 3" downpipe section
- Gaskets and hardware
- Installation instructions
Fitment Guide
| Year |
Make |
Model |
Engine |
Transmission |
| 2015-2021 |
Subaru |
WRX |
FA20 2.0L Turbo |
6MT ONLY |
Important: 6-speed MANUAL transmission ONLY. Does NOT fit CVT automatic transmission models.
Installation Notes
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Difficulty: Advanced | Estimated Time: 3-4 hours
- Direct bolt-on replacement for factory J-Pipe and downpipe
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6MT ONLY: Will NOT fit CVT automatic transmission
- May require O2 sensor spacer or CEL fix (sold separately)
- Professional installation recommended
- ECU tuning REQUIRED for safe operation
-
Off-road use only - removes catalytic converter
- Will not pass emissions testing
Performance Benefits
- 25-35 HP gain with proper tuning
- 30-40 ft-lbs torque increase
- Significantly reduced turbo lag
- Faster turbo spool and boost response
- Improved throttle response
- Aggressive turbo sound with pops/crackles
- Better exhaust flow for big turbo upgrades
- Reduced backpressure by 40-50%
- Lower exhaust gas temperatures (EGT)
Supporting Mods Recommended
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REQUIRED: ECU tuning (Cobb Accessport, EcuTek) - DO NOT run without tune!
- O2 sensor spacer or CEL eliminator
- Cat-back exhaust system (3" recommended)
- Cold air intake
- Upgraded intercooler (TMIC or FMIC)
- Boost controller
- Upgraded fuel pump (for higher boost)
FAQ
Q: Will this fit my CVT WRX?
A: No, this is designed for 6-speed manual transmission ONLY. CVT models have a different exhaust configuration and are not compatible.
Q: Will I get a check engine light?
A: Likely yes, since this removes the catalytic converter. You'll need an O2 sensor spacer/CEL fix or ECU tuning to eliminate the code.
Q: Is this street legal?
A: No, this is for off-road/race use only. Removing catalytic converters is illegal for street use in most areas and will not pass emissions.
Q: Do I NEED a tune?
A: YES, absolutely required! Running a catless J-Pipe without a tune can cause serious engine damage due to incorrect air/fuel ratios. Get a professional tune immediately after installation.
Q: What power gains can I expect?
A: With proper tuning: 25-35 HP and 30-40 ft-lbs torque. Many WRX owners see 280-300 WHP with J-Pipe, intake, and tune. Best results with full exhaust and intercooler.
Q: Will this fit the WRX STI?
A: No, this is designed for FA20 WRX only. The STI uses a different EJ257 engine with different exhaust routing.
Q: Does this reduce turbo lag?
A: Yes! This is one of the best mods for the FA20 WRX. Turbo spools significantly faster with reduced backpressure, improving throttle response dramatically.
Q: What's the difference between J-Pipe and downpipe?
A: The J-Pipe is the section that connects to the turbo (shaped like a "J"), and the downpipe connects to the cat-back. This combo replaces both sections for maximum flow.
For off-road/race use only. Removes catalytic converter - not legal for street use. Will not pass emissions testing. 6MT ONLY - NOT compatible with CVT. ECU tuning REQUIRED - do not run without tune! Check local laws before installation. Professional installation and tuning required.