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Invidia Gemini R400 single layer quad titanium tip cat-back exhaust for 2015-2021 Subaru WRX/STI main view
Side profile of Invidia R400 exhaust showing mandrel-bent piping and flat-bottom muffler
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Invidia 2015+ Subaru WRX / STI Gemini/R400 Single Layer Quad Titanium Tip Cat-Back Exhaust

Invidia
INVHS15STIGM4ST
HS15STIGM4ST
Catback
20+ Units In Stock - Ships Next Business Day
$ 2,640.40 $ 1,626.95
$ 1,626.95

SKU: HS15STIGM4ST 

Invidia 2015+ Subaru WRX / STI Gemini/R400 Single Layer Quad Titanium Tip Cat-Back Exhaust

The Invidia Gemini R400 Single Layer Quad Titanium Tip Cat-Back Exhaust (HS15STIGM4ST) is precision-engineered for 2015–2021 Subaru WRX and STI sedan models, offering superior performance gains, a rich deep sporty exhaust note, and premium styling.

Constructed from mandrel-bent SUS304 polished stainless steel piping with minimal bends and larger diameter for optimal flow, it features Advantex muffler technology for drone-free sound, flat-bottom aerodynamic design, and single-layer rolled titanium quad tips (4.5-inch diameter) with robot TIG welding for exceptional durability and a high-end burnt titanium finish.

Key Features

  • SUS304 Stainless Steel Piping: Mandrel-bent with larger diameter and minimal bends for unrestricted exhaust flow and significant HP/torque increases.
  • Advantex Muffler Technology: Continuous internal piping and acoustic dampening for a refined, deep boxer rumble without cabin drone.
  • Single Layer Quad Titanium Tips: Rolled 4.5-inch burnt titanium tips for heat resistance, aggressive aesthetics, and lightweight performance.
  • Aerodynamic Flat-Bottom Muffler: Enhances high-speed stability, reduces weight, and promotes efficient exhaust evacuation.
  • OEM-Compatible Fit: Direct bolt-on installation using factory hangers and flanges (new gaskets and hardware included).

Product Notes

  • Delivers measurable horsepower and torque gains while enhancing throttle response and remaining emissions-compliant.
  • Balances aggressive sound for track use with refined tone for daily driving – fills the gap between Q300 and N1 systems.
  • Titanium tips provide a unique burnt finish that resists discoloration and complements Subaru's sporty look.

Warranty: Lifetime limited against manufacturing defects.

Installation Notes

  • Professional installation recommended for optimal alignment and torque specifications.
  • Bolt-on design no cutting or welding required uses OEM mounting points.
  • May require adapter for certain downpipes inspect clearance with aftermarket suspension.

This Part Fits

Year Make Model Submodel
2015–2021 Subaru WRX Sedan (Base, Premium, Limited)
2015–2021 Subaru WRX STI Sedan (Base, Limited)

Why Choose Invidia Gemini R400?

  • Race-proven design from a leader in Subaru performance exhausts, offering the perfect balance of power, sound, and style.
  • Superior craftsmanship with CNC flanges, robot TIG welding, and premium materials for long-term reliability.
  • Engineered to enhance the natural Subaru boxer engine tone while providing noticeable performance upgrades.

Frequently Asked Questions

  • Q: Will this fit my 2020 STI Limited sedan?
    A: Yes, fully compatible with all 2015–2021 WRX and STI sedan models, including Limited trims.
  • Q: How does the R400 sound compared to the Q300?
    A: The R400 delivers a deeper, more aggressive tone with greater volume than the Q300, but still refined for street use.
  • Q: Does it require a downpipe or tune?
    A: No tune needed standalone, but pairs excellently with Invidia downpipes for maximum power gains.

Shipping & Handling

  • Method: Ground freight delivery only.
  • Availability: Usually ships within 1-2 business days.
  • Packaging: Securely crated with protective foam for maximum transit protection.

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