APEXi N1 EVO Extreme Performance Catback System - 2015-2021 Subaru WRX / STI

The A’PEXi N1-X Evolution Extreme takes the proven performance of the original N1 system and refines it for modern WRX and STI platforms. Designed around a straight-through layout for maximum flow, it integrates an internal hybrid silencer that delivers a deep, aggressive tone under throttle with composed resonance during cruising. Each system is finished with lightweight titanium tips that feature a rolled, riveted double-pipe diffuser design to reduce surface temperatures and produce a striking heat gradation appearance.

Key Features

• Straight-Through Design: Optimized for efficient exhaust flow and responsive turbo performance.
• Hybrid Silencer: Combines free-flowing power characteristics with refined acoustic balance.
• Patented Megaphone Piping: Enhances torque and throttle response via a swirling exhaust gas flow effect.
• Premium TIG-Welded Construction: Built entirely from SUS304 stainless steel for durability and corrosion resistance.
• Lightweight Titanium Tips: Dual-wall rolled, angle-cut design with authentic heat-treated finish.
• Bolt-On Fitment: Direct installation for VA-chassis WRX and STI models—no cutting or welding required.

APEXi N1 EVO Extreme VA WRX/STI Performance Catback System

Why We Like It

A perfect mix of sound, performance, and craftsmanship—this system gives the VA WRX/STI platform the right balance of daily driveability and motorsport edge. The heat-treated titanium tips are a signature A’PEXi touch that set off any rear end visually.

Specifications

• Exhaust Type: N1-X Evolution Extreme Muffler
• Piping Diameter: 76.2 mm → 63.5 mm × 4
• Tip Diameter: 93 mm × 4
• Pieces: 4
• Exhaust Tip Style: Titanium dual-wall rolled, angle-cut (riveted)
• Piping Material: SUS304 Stainless Steel
• Muffler Material: SUS304 Stainless Steel
• Muffler Tip Material: TP270 Grade Titanium
• Sound Level: 94.4 dB @ 4,500 RPM
• Bolt-On: Yes

Installation Notes

• Direct bolt-on installation; reuses factory hangers and hardware where applicable.
• Ensure even gasket compression and proper tip alignment before final torque.
• Professional installation recommended for best fit and sealing.
• Cleaning Note: Do not use harsh chemicals or metal polish on titanium tips. Use standard isopropyl alcohol only.

What’s in the Box

• A’PEXi N1-X Evolution Extreme Muffler system (4 pieces)
• Gaskets and installation hardware
• Instruction manual

Compatibility & Disclaimers

For VA-chassis WRX and STI models. Designed for off-road or motorsport use in some regions. Check local regulations regarding exhaust modifications and noise limits before installation.