The Nissan GT-R R35 represents a pinnacle of Japanese engineering, combining advanced all-wheel drive with a formidable twin-turbo V6. While the VR38DETT engine is a masterpiece from the factory, like all mass-produced systems, it comes with compromises. The exhaust system, particularly the downpipes, is a significant bottleneck. For owners seeking to unlock the car's true potential and experience that signature aggressive exhaust note, upgrading the downpipes is the single most effective modification. Among the top-tier manufacturers, Akrapovic stands as a benchmark for quality, sound engineering, and performance. This guide explores five of the best Akrapovic downpipe solutions available for the GT-R, detailing how each option can help you achieve a more aggressive sound and increased power output.

Why the Downpipe is the Key to GT-R Performance

The downpipe connects directly to the exhaust side of the twin-turbos and routes exhaust gases to the rest of the system. The factory units are restrictive, featuring dense catalytic converters and relatively narrow piping designed to meet global noise and emissions regulations. By upgrading to a high-flow or catless Akrapovic downpipe, you immediately reduce backpressure on the turbos. This allows the turbos to spool faster, lowers exhaust gas temperatures (EGTs), and can unlock significant horsepower gains when paired with a proper engine tune. The sound character also transforms, becoming deeper, louder, and far more aggressive.

Top 5 Akrapovic GT-R Downpipes

Akrapovic offers a range of downpipe systems tailored to different performance goals, legal requirements, and sound preferences. The materials, diameters, and catalyst configurations vary, ensuring there is an option for every GT-R owner.

1. Akrapovic Evolution Downpipe

The Akrapovic Evolution Downpipe is designed for the enthusiast who demands maximum flow and track-ready performance. Constructed from high-strength stainless steel or lightweight titanium, this downpipe eliminates the factory bottleneck to allow unrestricted exhaust pulse delivery. It is typically offered in a catless configuration, making it ideal for track use or for owners who have no emissions compliance concerns.

  • Construction: Lightweight titanium or high-grade stainless steel with a durable thermal coating.
  • Piping Diameter: 3.5 inches, significantly reducing backpressure compared to stock.
  • Power Gains: Up to 40-50 whp when combined with a professional ECU calibration.
  • Sound Character: Extremely deep and aggressive with pronounced turbo spooling sounds. It produces a sharp, metallic crackle on the overrun.
  • Best For: Track-focused GT-Rs or owners chasing maximum turbo response and top-end power.

2. Akrapovic Slip-On Exhaust System with Downpipe

For those seeking a complete exhaust overhaul, the Akrapovic Slip-On Exhaust System with an integrated downpipe provides a balanced, high-performance solution. This system is engineered as a whole, meaning the downpipe is specifically tuned to work with the muffler and tips to deliver a refined yet powerful sound. The slip-on design simplifies installation while ensuring a perfect fit.

  • Construction: Titanium or stainless steel muffler with carbon fiber or titanium heat shields and tips.
  • Compatibility: Designed for a direct bolt-on fitment with OEM hangers.
  • Sound Character: A deep, controlled aggression. It is loud under full throttle but remains civil and drone-free at cruising speeds, especially with the optional valved muffler.
  • Power Gains: 30-40 whp with a tune, combined with significant weight savings over the stock system.
  • Best For: Daily drivers who want a comprehensive upgrade with high-quality craftsmanship and a refined sound profile.

3. Akrapovic Downpipe with Sport Catalyst

Legality and performance do not have to be mutually exclusive. The Akrapovic Downpipe with a Sport Catalyst utilizes a high-flow metallic catalyst to clean up exhaust gases while offering vastly superior flow compared to the restrictive factory unit. This is the ideal choice for GT-R owners who need to pass emissions tests but still want an aggressive sound and power bump.

  • Construction: Stainless steel with a 200-cell or 100-cell metallic sport catalyst.
  • Compliance: Legal for street use in many jurisdictions (check local laws) and often avoids Check Engine Lights when paired with the correct tune.
  • Sound Character: Deep and aggressive but slightly more subdued than a catless setup. The catalyst muffles some of the higher-frequency rasp, resulting in a thick, muscular tone.
  • Power Gains: 25-35 whp, preserving low-end torque that can sometimes be lost with completely open downpipes.
  • Best For: Owners who drive their GT-R on the street regularly and require emissions compliance.

4. Akrapovic GT-R Downpipe with Valvetronic Technology

Offering the best of both worlds, the Valvetronic-equipped downpipe uses an electronically controlled butterfly valve to alter the exhaust path. When the valve is closed, exhaust gases are routed through a smaller, quieter path. When opened, the system flows freely for maximum performance and a raw, race-car sound. This technology gives the driver complete control over the noise output.

  • Construction: High-quality stainless steel with a robust electronic actuator and valve assembly.
  • Control: Can be wired to a boost controller, RPM signal, or a remote switch for on-demand sound changes.
  • Sound Character: Quiet and reserved in "closed" mode for early morning starts, transforms into an aggressive, full-race roar when opened. It is the most versatile system available.
  • Power Gains: 25-40 whp depending on the valve map and supporting mods.
  • Best For: Enthusiasts who want the ability to switch between stealth and aggression effortlessly.

5. Akrapovic GT-R Downpipe Kit

The Akrapovic Downpipe Kit is the complete package, containing everything required for a hassle-free installation. It includes the downpipes, all necessary gaskets, bolts, springs, and mounting hardware. This ensures a perfect, leak-free seal and eliminates the need to source individual components. It is engineered for a precise fit on the GT-R.

  • Contents: Full set of downpipes, OEM-quality gaskets, stainless steel fasteners, and installation instructions.
  • Fitment: Guaranteed direct fit for R35 GT-R models (check compatibility for pre-2012 vs. post-2012 revisions).
  • Sound Character: Matches the acoustic profile of the specific downpipes included in the kit (e.g., Evolution or Sport Cat).
  • Power Gains: Varies based on the specific downpipe configuration selected.
  • Best For: DIY installers and perfectionists who want a complete, factory-quality installation without having to purchase additional parts.

Installation and Tuning Considerations

Installing downpipes on a Nissan GT-R is a labor-intensive process that typically requires lifting the vehicle, removing the underbody panels, and carefully maneuvering the old components out. It is highly recommended to have this work performed by a professional shop familiar with the R35 platform. Once installed, an ECU tune is mandatory to fully realize the benefits of the improved flow. Without a tune, the increased oxygen flow can cause the engine to run lean or trigger diagnostic trouble codes. Platforms such as the Cobb Accessport or ECUTek are industry standards for calibrating the GT-R's engine management system, allowing tuners to optimize fuel, timing, and boost for the new downpipes. Cobb Tuning offers a dedicated Accessport for the GT-R that makes flashing a new tune straightforward.

Selecting the Right Akrapovic System

Choosing the right Akrapovic downpipe depends entirely on your specific goals. If you are building a high-horsepower track weapon, the Evolution Downpipe provides the lowest restriction and highest peak power. If your GT-R sees daily duty and you need to pass a tailpipe test, the Sport Catalyst version is the logical choice. For those who refuse to compromise on sound flexibility, the Valvetronic technology offers an unparalleled range. For more information on specific part numbers and to view the entire range of GT-R upgrades, visit the official Akrapovic GT-R catalog. Reputable distributors like Z1 Motorsports also provide expert guidance and competitive pricing on these premium systems. The investment in an Akrapovic downpipe is an investment in the longevity and performance of your VR38DETT engine, delivering a driving experience that is both exhilarating and refined.