Understanding the Demands of 800+ HP

The Nissan GT-R, particularly the R35 generation, is a marvel of modern engineering. Its twin-turbocharged V6 and sophisticated all-wheel-drive system have made it a benchmark for performance. However, when owners begin pushing power levels beyond 800 horsepower, the factory drivetrain components reach their limits. The stock clutch, designed for approximately 500-550 horsepower, slips under the immense torque generated by high-output builds. Similarly, the stock gears, while robust for normal use, can suffer from fatigue, chipping, or even catastrophic failure under repeated hard launches and aggressive shifting at elevated power levels.

At 800+ horsepower, the demands on the drivetrain are severe. The clutch must not only hold the power without slipping but also provide consistent engagement for daily driving and track use. The gears must withstand shock loads from high-rpm shifts and the brutal torque of a twin-turbocharged engine. Upgrading these components is not just about gaining performance—it is about ensuring reliability and preventing expensive failures. A properly selected clutch and gearset combination transforms the GT-R into a machine that can handle sustained high-power operation without compromise.

Beyond raw strength, the right upgrades improve the driving experience. A high-performance clutch offers better pedal feel and modulation, while a close-ratio or sequential gearset allows for faster, more precise shifts. These changes directly impact lap times, quarter-mile performance, and overall confidence behind the wheel. For enthusiasts investing thousands of dollars in engine modifications, overlooking the drivetrain is a critical mistake. This guide covers the best clutch and gearset options available, providing the knowledge needed to build a GT-R that is as durable as it is fast.

Top Clutch Upgrades for High-Horsepower GT-Rs

Selecting the right clutch for an 800+ horsepower GT-R requires careful consideration of driving style, intended use, and power delivery characteristics. The clutch must handle sustained torque loads, resist heat fade, and provide consistent bite point engagement. Below are the most proven and widely recommended clutch systems for high-output R35 builds.

Exedy Twin Plate Clutch

The Exedy Twin Plate clutch is a popular choice for GT-R owners targeting 800-1000 horsepower. It features a dual-disc design that increases clamping force while maintaining a relatively light pedal feel compared to single-plate race clutches. The use of high-friction material and a rigid intermediate plate ensures excellent power transfer without excessive wear. Exedy's reputation for quality control makes this a reliable option for both street and track use.

One of the key advantages of the Exedy twin plate is its drivability. The clutch engages smoothly with moderate pedal effort, making stop-and-go traffic manageable. It does not exhibit the harsh, on-off characteristics of some aggressive race clutches. However, it does require a proper break-in period of approximately 500-1000 miles to ensure optimal performance. After break-in, the Exedy twin plate can handle repeated hard launches and high-rpm shifts without slipping. For owners running hybrid or upgraded turbos in the 800-900 horsepower range, this clutch is often the gold standard. More details can be found on the official Exedy website.

OS Giken Super Single Clutch

The OS Giken Super Single clutch is engineered for enthusiasts who demand track-ready performance with occasional street use. Its single-plate design might sound less capable than a twin plate, but OS Giken's advanced materials and engineering allow it to handle power levels well above 800 horsepower. The clutch uses a high-friction ceramic-metallic disc and a pressure plate with increased clamping force, providing a positive engagement that holds torque effectively.

This clutch is known for its durability under extreme conditions. The disc material is resistant to glazing and heat fade, making it suitable for lapping sessions and drag racing. The pedal feel is firmer than the Exedy twin plate, but still manageable for daily driving if the car is driven regularly. One trade-off is that the engagement can be more abrupt, requiring a careful foot for smooth starts. For GT-R owners who prioritize track performance and are comfortable with a more aggressive clutch, the OS Giken Super Single is an excellent choice. The OS Giken website provides technical specifications and application details.

ACT Heavy Duty Clutch

Advanced Clutch Technology (ACT) offers a Heavy Duty clutch kit that has gained a strong following in the GT-R community. The ACT kit uses a high-clamping-force pressure plate and a robust disc with organic or ceramic friction materials, depending on the application. This clutch is designed to handle substantial torque increases without the noise or vibration associated with some racing clutches.

The ACT Heavy Duty clutch is particularly appealing for builds that emphasize street usability. It provides a predictable pedal feel that is not overly stiff, and the engagement is progressive enough for smooth launches. The increased clamping force directly addresses the slipping issue common with stock clutches at higher power levels. ACT also offers a range of disc materials, allowing owners to tailor the clutch to their specific needs. For those seeking a balance of performance and comfort, the ACT Heavy Duty clutch is a strong contender.

Other Notable Clutch Options

Beyond the three main choices, several other manufacturers offer clutches suitable for 800+ horsepower GT-Rs. The South Bend Clutch Stage 5 and Stage 6 kits are known for their durability in high-torque applications. The Competition Clutch Twin Disc provides excellent holding power with a smooth engagement. Additionally, the HTC (High Torque Clutch) systems from reputable tuners are worth investigating for extreme builds exceeding 1000 horsepower. Each option has unique characteristics in terms of pedal feel, noise, and longevity, so it is wise to consult with a GT-R specialist before making a final decision.

Gearset Upgrades for Maximum Performance

While the clutch handles power transfer from the engine, the gearset is responsible for transmitting that power to the driveshafts and wheels. At 800+ horsepower, the stock gears can experience bending stress, pitting, or tooth fracture, especially during hard launches or when using aggressive tire compounds. Upgrading the gearset improves strength, shift quality, and often allows for optimized gear ratios that better suit the engine's power band.

Nismo GT-R Gearset

Nismo, Nissan's official motorsport division, produces a gearset designed specifically for high-performance GT-R applications. This OEM-grade upgrade uses higher-grade steel and refined heat treatment processes to increase fatigue resistance. The Nismo gearset maintains the standard gear ratios, ensuring compatibility with the factory transmission control unit and shift logic. This makes it a straightforward upgrade for owners who want increased durability without changing the driving character of the car.

The installation of a Nismo gearset is typically less invasive than aftermarket options because it uses the same case and shift forks. The improved material properties significantly reduce the risk of gear failure at power levels up to 900 horsepower. For GT-R owners who track their cars or perform frequent launch control starts, this gearset provides peace of mind. Nismo also offers a reinforced differential and driveshaft components to complete the drivetrain upgrade package. Official information is available through the Nismo parts network.

OS Giken Gearset

OS Giken is widely recognized for producing some of the strongest gearsets available for the R35 GT-R. Their design focuses on using premium materials and a unique tooth profile that distributes load more evenly, reducing stress concentrations. The OS Giken gearset is available in multiple ratio configurations, including a close-ratio set that keeps the engine in the optimal power band during shifts. This translates to faster acceleration and better lap times.

The close-ratio gearset is particularly effective for track use, as it reduces the rpm drop between gears, allowing the engine to stay in its peak torque range. For drag racing, the standard ratio set with increased strength is preferred. OS Giken gears are machined to tight tolerances, ensuring quiet operation and long service life. They are a direct replacement for the factory gears and require professional installation. The OS Giken gearset is a top-tier choice for GT-R owners who demand maximum strength and performance. Detailed specs can be found on the OS Giken drivetrain page.

HKS Sequential Gearbox

For those seeking the ultimate in shift speed and durability, the HKS Sequential Gearbox is the premier solution. This is a complete replacement transmission that uses a sequential shift mechanism, eliminating the traditional H-pattern gate. Shifts are performed with a simple push or pull of the lever, with no clutch required on upshifts under load. This system is standard in many professional racing series and offers the fastest possible gear changes.

The HKS sequential gearbox is built to handle power levels exceeding 1000 horsepower. The internal components are forged and heat-treated for maximum strength, and the housing is designed for rigidity. The gear ratios are optimized for high-speed circuits and aggressive driving. However, this upgrade comes with significant costs and requires extensive modifications to the vehicle, including a dedicated shifter assembly and sometimes a custom clutch system. It is best suited for dedicated race cars or high-end builds where cost is secondary to performance. Additional information is available through HKS USA.

Aftermarket Gearset Considerations

When choosing a gearset, it is important to consider the supporting modifications. Reinforced shift forks, upgraded synchros, and a billet shift collar are often recommended to match the increased strength of the gears. The transmission fluid should also be upgraded to a high-performance synthetic that can handle higher temperatures. Furthermore, the differential and axles must be capable of handling the additional torque. A comprehensive approach ensures that the entire drivetrain works harmoniously without weak points.

The Benefits of a Comprehensive Drivetrain Upgrade

Upgrading both the clutch and gearset together yields synergistic benefits that go beyond the sum of the individual parts. A high-performance clutch ensures that the engine's power is transferred cleanly to the transmission, while a reinforced gearset ensures that power is delivered to the wheels without loss or failure. This combination improves acceleration, shift quality, and overall vehicle reliability.

One of the most noticeable improvements is in shift feel. A high-quality clutch with proper modulation, paired with a gearset that has minimal play and precise engagement, transforms the driving experience. Gear changes become crisp and predictable, allowing the driver to focus on corner entry and exit speeds rather than worrying about drivetrain compliance. This is particularly important on track where every fraction of a second counts.

Durability is another major benefit. With both components upgraded, the risk of a failure that could cause extensive damage to the transmission case, bellhousing, or other parts is significantly reduced. The cost of repairing a broken gear or damaged clutch is far higher than the initial investment in quality components. For owners who track their cars or participate in competitive events, this reliability is essential. Additionally, a properly matched clutch and gearset can improve fuel economy by reducing drivetrain losses, though this is a secondary consideration in a high-performance build.

Installation and Supporting Modifications

Installing a clutch and gearset in a GT-R is a complex process that should be performed by a shop with experience in high-power Nissan applications. The transmission must be removed, which involves disconnecting the driveshaft, transfer case, and various sensors. The flywheel should be resurfaced or replaced, and the pilot bearing must be inspected. For the gearset, the transmission case must be split, and all bearings, synchros, and seals should be replaced during the rebuild.

Several supporting modifications are strongly recommended during a clutch and gearset upgrade:

  • Reinforced Shift Forks: The factory shift forks can bend under the increased force from a high-clamping-pressure clutch or during aggressive shifts. Upgraded billet shift forks prevent this failure point.
  • Billet Shift Collar: The shift collar engages the shift forks and can wear or fracture with hard use. A billet steel collar provides increased strength.
  • Upgraded Transmission Mount: A stiffer mount reduces drivetrain movement and improves shift consistency, especially under high load.
  • High-Performance Transmission Cooler: Increased power generates more heat in the transmission fluid. A dedicated cooler extends fluid life and prevents thermal breakdown.
  • Driveline Balancing: After installing a new clutch and gearset, the entire driveline should be balanced to reduce vibrations and prevent premature bearing wear.

Proper break-in for a new clutch is critical. Most manufacturers recommend a break-in period of 500-1000 miles, during which the clutch is subjected to moderate, varied loads without aggressive launches or sustained high-rpm operation. This allows the friction surfaces to bed in evenly and ensures maximum holding power throughout the clutch's life. Ignoring the break-in procedure can lead to glazing, chatter, or premature failure.

Selecting the Right Combination for Your Build

Choosing the ideal clutch and gearset depends on the specific goals for the GT-R. For a street-driven car that sees occasional track use, the Exedy Twin Plate clutch paired with the Nismo gearset offers a proven balance of drivability and strength. This combination handles 800-900 horsepower comfortably while remaining civil enough for daily driving. Owners of this setup report good pedal feel, quiet operation, and reliable performance during lapping sessions.

For a car that spends significant time on the track or is used for time attack events, the OS Giken Super Single clutch combined with the OS Giken close-ratio gearset provides a more aggressive setup. The clutch's positive engagement and the gearset's optimized ratios deliver faster acceleration and better lap times. The firmer pedal feel and more abrupt engagement require some adaptation but reward the driver with direct feedback and precise control. This combination is also well-suited for drag racing applications where consistent, hard launches are required.

At the extreme end, a dedicated race car or a build targeting 1000+ horsepower should consider the HKS Sequential Gearbox with a compatible multi-plate clutch system. This setup offers the fastest shifts and the highest level of durability, but it comes with a significant price premium and reduced street usability. Cars equipped with this transmission are purpose-built for competition and require a higher level of maintenance and expertise to operate.

Budget is also a determining factor. A basic clutch and gearset upgrade—such as an ACT Heavy Duty clutch with a Nismo gearset—can be completed for a fraction of the cost of a full sequential transmission system. However, investing in higher-tier components from the outset can be cheaper than replacing a failed gearset later. It is recommended to over-spec the components relative to the current power output to allow for future engine upgrades without needing to repeat the drivetrain work.

Conclusion

Building a Nissan GT-R to reliably handle 800+ horsepower requires thoughtful selection of drivetrain components. The clutch and gearset are the linchpins of this system, directly influencing power delivery, shift quality, and long-term durability. Options from Exedy, OS Giken, ACT, Nismo, and HKS each offer distinct advantages tailored to different driving styles and applications. By matching the clutch and gearset to the specific requirements of the build, owners can create a GT-R that not only performs at its peak but also withstands the rigors of high-horsepower operation.

The investment in quality drivetrain components is an investment in the longevity and enjoyment of the vehicle. Whether the goal is lower lap times, faster quarter-mile passes, or simply a more responsive street car, the right clutch and gearset upgrade transforms the driving experience. With careful planning, professional installation, and proper maintenance, a 800+ horsepower GT-R equipped with these upgrades will deliver consistent, thrilling performance for years to come.