AMS Performance GR Supra B58 Street Downpipe w/GESI Catalytic Converter

Overview

Upgrade your exhaust system with the AMS Performance Street Downpipe, engineered specifically for the Toyota GR Supra A90/A91. Designed to improve exhaust flow while maintaining street usability, this high-quality downpipe enhances turbo performance, sound, and overall driving response.

Key Features

• High-Flow GESI Catalytic Converter
  Includes an EPA-verified Ultra High Flow GESI catalytic converter rated to support 800+ horsepower.

• 4.5” Mandrel-Bent Piping
  Large-diameter, smooth-bent tubing reduces restriction and maintains optimal exhaust velocity.

• 304 Stainless Steel Construction
  Heavy-gauge stainless steel provides durability, corrosion resistance, and long-term reliability.

• Precision CAD Engineering
  Designed for OEM-level fitment with factory mounting points and flanges.

• Factory O₂ Sensor Retention
  Integrated sensor bungs allow reuse of factory oxygen sensors without adapters.

• Stock & Aftermarket Exhaust Compatibility
  3.15” (80mm) outlet mates with factory or compatible cat-back systems.

Performance Benefits

• Improved Turbo Spool
  Reduced back pressure helps the turbocharger spool faster for quicker boost response.

• Increased Power Potential
  Enhanced exhaust flow supports horsepower gains when paired with proper tuning.

• More Aggressive Exhaust Tone
  Produces a deeper, sportier sound under acceleration while remaining street-friendly.

• Emissions-Conscious Performance
  High-flow catalytic converter balances performance and compliance in many U.S. states (check local regulations).

• Direct Bolt-On Installation
  No cutting required for installs — engineered as a direct replacement for the factory downpipe.

** Not CARB Legal**