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SKU: 31021-BF001 | UPC: 4957266931790
HKS LEGAMAX Premium Cat-Back Exhaust Subaru WRX STI 2015-2021 USDM
The HKS LEGAMAX Premium is a full cat-back exhaust system designed for the 2015-2021 Subaru WRX STI sedan (USDM VA chassis). It replaces the stock system from the catalytic converter back with mandrel-bent piping for improved exhaust flow and throttle response. Drivers experience noticeable power and torque increases along with a refined deep sports exhaust note.
Key Features
- SUS304 Stainless Steel Construction: Full system built from durable 304-grade stainless steel resists corrosion and ensures long-term performance under high heat.
- Variable Pipe Diameter: 60.0mm to 80.0mm main piping expands to 115mm rolled edge tip for smooth high-flow exhaust without backpressure.
- Weight Reduction: 15.2kg system weighs 21% less than stock 19.0kg setup improving handling and acceleration.
- Large Volume Chamber Muffler: Internal chamber design quiets drone while amplifying low-end torque and mid-range power.
- Bolt-On Fitment: Direct replacement uses factory hangers and mounts for straightforward installation on STI models.
Product Notes
- Requires removal of stock resonators for full installation.
- Clean exhaust tip regularly to maintain appearance.
- Ships in protective oversized box to prevent damage.
Installation Notes
- Professional installation recommended.
- Uses OEM catalytic converter flange and gasket.
- Compatible with factory hardware and hangers no modifications needed.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2015-2021 | Subaru | WRX STI | Sedan (Base/Limited USDM) |
Why Choose HKS?
- HKS pioneered JDM performance parts since 1973 with motorsport-proven designs.
- Every exhaust undergoes rigorous dyno testing for real-world gains.
- Precision TIG-welded construction matches OEM quality with aftermarket flow.
Frequently Asked Questions
-
Q: Does this fit 2015-2021 WRX STI hatchback models?
A: Designed for USDM sedan only VAG chassis. Hatchback requires separate part number. -
Q: What material is used in construction?
A: Full SUS304 stainless steel piping muffler and 115mm single-layer tip for heat resistance and shine. -
Q: What is the warranty and install process?
A: HKS offers 1-year limited warranty. Bolt-on install takes 1-2 hours with basic tools professional tuning advised for ECU.
Shipping & Handling
- Method: UPS/FedEx Ground
- Availability: In stock - ships same or next business day
- Packaging: Oversized box 59 x 13 x 13 inches
- Weight: 37.9 lbs shipping / 33.7 lbs product
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