The Challenge of 700 Horsepower in an R33 GT-R

The Nissan R33 GT-R, produced from 1995 to 1998, holds a hallowed place in automotive history. Its RB26DETT engine, advanced ATTESA all-wheel-drive system, and race-bred chassis made it a dominant force on the streets and circuits of the 1990s. Yet, even this engineering marvel has its limits. While the RB26 can be built to reliably produce 700 wheel horsepower with forged internals, upgraded turbos, and a proper fuel system, the factory transmission was not designed for that level of torque. The Getrag 5-speed manual, though stout by mid-1990s standards, becomes a weak link once you push past approximately 500–550 wheel horsepower.

To achieve stable, consistent performance at the 700 hp mark, the entire driveline must be addressed. Without a properly upgraded clutch and gearbox, you risk broken input shafts, shattered synchros, clutch slip, or even catastrophic housing failure. This guide provides a comprehensive, technically detailed roadmap for upgrading the R33 GT-R transmission to handle 700 hp reliably—whether for street driving, track days, or drag racing.

Understanding the R33 GT-R Transmission System

Before selecting parts, it is essential to understand what you are working with. The R33 GT-R uses a variant of the Getrag 5-speed manual transmission, designated as the FS5R30A. This transmission was shared in various forms with other Nissan high-performance models and is known for its relatively compact size and decent shift feel. However, its internal components have known failure points at elevated power levels.

Key Transmission Components

  • Getrag FS5R30A 5-Speed Manual: The core gearbox. It features helical-cut gears, a direct-drive 4th gear, and a cast-aluminum housing. The main shaft, countershaft, and synchronizer assemblies are the areas most prone to failure under high torque.
  • ATTESA All-Wheel-Drive System: The transfer case is directly attached to the rear of the transmission and distributes torque to the front wheels. At 700 hp, the transfer case itself can be stressed, particularly the chain and the front output shaft bearing.
  • Active LSD (Limited Slip Differential): The rear differential uses a hydraulic active system that can overheat or fail when subjected to continuous high-power launches. Upgrading or locking the rear diff is often necessary.
  • Clutch and Flywheel Assembly: The factory dual-mass flywheel and single-plate clutch are completely inadequate at 700 hp. They must be replaced with a high-capacity unit.

Common Failure Points at 700 HP

When the R33 GT-R is pushed to 700 hp, the transmission typically fails in predictable ways. Understanding these helps guide your upgrade choices.

  • Input shaft failure: The 26-spline input shaft can twist or shear under high-torque shock loads, especially with a heavy clutch.
  • Synchro wear and breakage: The brass synchros overheat and wear rapidly, leading to grinding shifts, particularly in 2nd and 3rd gear.
  • Gear tooth spalling: The hardened surfaces of the gear teeth can flake or chip under sustained high load.
  • Clutch fork and pivot failure: The factory clutch fork bends or cracks when paired with a high-pressure plate.
  • Transfer case chain stretch or breakage: The chain linking the transmission output to the front drive can fail under aggressive launches.

Clutch Upgrades for 700 Horsepower

The clutch is the first line of defense between the engine and the rest of the driveline. At 700 hp, you need a clutch that can handle high torque capacity, provide consistent engagement, and survive repeated hard use without overheating or glazing.

Clutch Material Selection

Not all clutch materials are equal. For a 700 hp R33 GT-R, these are the most suitable options:

  • Ceramic (Sintered Iron): Offers very high friction coefficient and excellent heat resistance. Ideal for track and drag use. Engagement is aggressive, making it less ideal for stop-and-go traffic. Examples include the OS Giken twin-plate and Exedy Hyper Series.
  • Carbon-Carbon: Extremely high heat capacity and smooth engagement for a racing clutch. Expensive but offers the best performance for high-power applications. Common in top-level time attack builds.
  • Kevlar-based: Wears well and provides smooth engagement, but can overheat and lose friction under sustained heavy use. Generally not recommended for 700 hp track cars, but can work for street cars with mild driving habits.

Single Plate vs. Twin Plate vs. Triple Plate

  • Single Plate: The factory-style single-plate clutch cannot handle 700 hp. Even heavy-duty single-plate units with high clamping force tend to slip or cause excessive pedal effort. Avoid.
  • Twin Plate: The most common and practical upgrade for 700 hp. A twin-plate clutch (e.g., OS Giken R2C or Exedy Triple Disc) provides high torque capacity while maintaining a pedal feel that is acceptable for street use. The multiple discs spread the load and improve heat dissipation.
  • Triple Plate: Used for 800 hp and above, or for dedicated race cars. Offers the highest torque capacity but with very aggressive engagement and higher pedal effort. Not necessary for 700 hp but acceptable if you plan to push further.

Based on real-world results from the R33 GT-R community and professional build shops, these clutch kits have proven reliable at the 700 hp level:

  • OS Giken R2C Twin Plate: Widely considered the gold standard. Uses sintered iron discs, a lightweight chromoly flywheel, and a push-type release system. Pedal effort is approximately 30-50% heavier than stock. Handles up to 800 ft-lbs of torque.
  • Exedy Hyper Twin (06280D): A twin-plate design with ceramic discs. Offers excellent heat capacity and a relatively light pedal. Rated to approximately 750 ft-lbs.
  • ACT Heavy Duty (SB5-XTSS): A single-plate unit that uses a high-clamping pressure plate and a six-puck ceramic disc. While it can hold 700 hp, it has a very heavy pedal (60-80 lb-ft pedal effort) and is harsh for daily driving. Better suited for track-only cars.
  • ATS Carbonetic Twin Plate: Uses carbon-carbon discs for smooth engagement and high heat resistance. Very expensive but ideal for cars that see both street and track use.

Clutch Installation Considerations

A clutch is only as good as its installation. At 700 hp, small errors lead to big failures.

  • Use a new pilot bearing and release bearing. The factory parts are insufficient for high clamping loads. Upgrade to a high-quality sealed bearing (e.g., Koyo or NSK).
  • Replace the clutch fork and pivot ball. The OEM fork bends under high pressure. Use a billet steel fork (available from OS Giken, Nismo, or aftermarket suppliers).
  • Check pressure plate bolts and torque to spec. Use thread locker and torque in a cross pattern. The factory bolts can stretch, so replace them with ARP or equivalent high-strength fasteners.
  • Align the clutch disc carefully. Use an alignment tool to center the disc before tightening the pressure plate. Misalignment causes vibration, premature wear, and difficult shifting.
  • Bleed the clutch hydraulic system thoroughly. Air in the line leads to inconsistent disengagement and grinding shifts. Use a pressure bleeder for best results.

Gearbox Modifications for Stability

The clutch transmits power to the gearbox. At 700 hp, the gearbox internals require significant strengthening to survive repeated hard shifts and high-torque loads.

Gear Set Upgrades

Factory gears are case-hardened and designed for the stock torque output. At 700 hp, the stresses exceed what the factory metallurgy can handle. Upgrading to a billet gear set is the most effective way to ensure reliability.

  • OS Giken Gear Set (FS5R30A): A complete replacement gear set that includes all forward gears, input shaft, and countershaft. Uses high-strength nickel-chromium steel with shot-peened surfaces. Rated to 800+ hp. The gear ratios can be custom-ordered to suit your driving style.
  • PPG (Performance Parts Gearboxes) Gear Set: PPG offers straight-cut and helical-cut gear sets for the R33 GT-R. The straight-cut sets are stronger but noisier, while the helical sets are more street-friendly. PPG gear sets are a popular choice for drag and circuit builds.
  • PAR Engineering Gear Sets: PAR produces billet gear sets using 9310 alloy steel. They offer both close-ratio and standard-ratio options. Known for their durability in high-horsepower applications.

Synchronizer Upgrades

Factory brass synchros wear out quickly at 700 hp, especially if you shift aggressively. Upgraded synchros improve shift feel and prevent grinding.

  • Nismo Synchro Kit: Uses a molybdenum-coated brass material that is harder than stock. Provides improved durability and smoother engagement under high load.
  • OS Giken Synchro Set: Uses a carbon-coated design that offers reduced friction and higher heat tolerance. Ideal for track use.
  • Billet synchro hubs: Some aftermarket suppliers offer billet steel synchro hubs to replace the factory cast units. These prevent hub breakage under extreme shock loads.

Short Shifter and Shift Mechanism

At 700 hp, shift speed and precision become critical. A short shifter reduces the throw and improves gate feel, allowing for faster, more accurate shifts.

  • Nismo Short Shifter (FS5R30A): OEM quality with a 30% reduction in throw. Direct bolt-on with no modification required. Maintains factory shift feel while improving precision.
  • C's Short Shifter: Offers a more aggressive reduction (up to 40%) and includes a weighted knob for better feel. Can be slightly notchy compared to Nismo.
  • Billet aluminum shifter base bushings: Replace the factory rubber bushings in the shifter base with solid aluminum units. This removes slop and improves shift precision significantly, regardless of which shifter you use.

Strengthened Housing and Mounts

The transmission housing itself can flex or crack under high torque, and weak mounts allow the drivetrain to move excessively, causing shift linkage misalignment.

  • Transmission mount: Replace the factory rubber mount with a polyurethane or solid aluminum mount (e.g., Nismo, Cusco, or Whiteline). This reduces drivetrain movement and improves shift consistency.
  • Engine mounts: Stiffer engine mounts (e.g., Nismo solid or Cusco) prevent the engine from twisting under load, which reduces stress on the bellhousing and input shaft.
  • Reinforced bellhousing: Some aftermarket suppliers offer billet steel bellhousings that replace the factory aluminum unit. These are rarely necessary below 800 hp but can provide peace of mind for hard-launch applications.

Transfer Case Upgrades

The ATTESA transfer case is a common failure point at 700 hp, especially the chain and the front output shaft bearing.

  • Heavy-duty transfer case chain: Replace the OEM chain with a stronger aftermarket unit (e.g., OS Giken or Nismo). This prevents chain stretch and breakage during hard launches.
  • Bearing upgrade: Replace all transfer case bearings with high-speed, high-load ceramic hybrid bearings. This reduces friction and heat buildup.
  • Oil cooler: Transfer case oil overheats under prolonged high-power use. An external oil cooler with a thermostat and pump keeps temperatures in check and extends component life.

Fluid Selection and Cooling

Even with the best hardware, transmission reliability depends on proper lubrication and cooling. At 700 hp, the heat generated inside the gearbox is significantly higher than stock.

Transmission Oil

Use a high-quality GL-4 or GL-5 gear oil with the correct viscosity. Avoid using GL-5 in a gearbox that requires GL-4, as the high sulfur content in GL-5 can attack yellow metals (brass synchros).

  • Motul Gear 300 75W-90: A synthetic GL-4/GL-5 fluid that is safe for synchros and provides excellent high-temperature stability. Popular in the R33 GT-R community.
  • Red Line MT-90 (75W-90 GL-4): Specifically formulated for manual transmissions. Provides smooth shifting and good protection at high temperatures.
  • Torco RTF (Racing Transmission Fluid): A high-viscosity fluid designed for racing gearboxes. Ideal for track use but may cause notchiness in cold weather.

Transmission Oil Cooler

For extended track sessions or drag racing, a dedicated transmission oil cooler is highly recommended. Mount the cooler in a location with good airflow (e.g., the front bumper or intercooler duct) and use a thermostatic sandwich plate to control oil flow.

  • Setrab or Mocal oil cooler: A 25-row cooler with -12 AN fittings provides sufficient cooling for 700 hp applications.
  • Thermostatic valve: Keeps the oil at operating temperature (180-200°F) for street driving while allowing full flow to the cooler when temps rise.

Installation Best Practices

Proper installation is the difference between a reliable 700 hp build and a recurring nightmare. These steps are critical:

  • Use a torque wrench on every fastener. The bellhousing bolts, pressure plate bolts, driveline bolts, and transfer case bolts all have specific torque values. Under-tightening causes loosening; over-tightening causes thread or housing damage.
  • Inspect the flywheel surface. If reusing a flywheel, ensure it is perfectly flat and free of cracks, hot spots, or glazing. For 700 hp, a billet steel or chromoly flywheel is recommended over the factory dual-mass unit.
  • Check pilot bearing alignment. The pilot bearing (or bushing) must be correctly aligned to the input shaft. An offset pilot bearing causes vibration and premature bearing failure.
  • Use a dial indicator to check concentricity. The bellhousing should be within 0.005 inches of concentric with the crankshaft. If not, use offset dowel pins to correct alignment.
  • Apply thread locker to critical fasteners. Use Loctite 242 (blue) for pressure plate bolts and 262 (red) for flywheel bolts. Allow proper cure time before starting the engine.
  • Consider professional installation. If you lack experience with Nissan manual transmissions, enlist a specialist. The cost of professional installation is far less than rebuilding a damaged gearbox.

Testing and Tuning

After installation, systematic testing ensures that everything is working correctly before you push the car to 700 hp.

Break-In Procedure

New clutch discs and gears require a break-in period to achieve optimal performance and longevity.

  • Drive the car gently for 200-300 miles. Avoid aggressive launches, full-throttle shifts, or high-rpm operation during this period.
  • Perform gradual load cycles. Accelerate in 3rd or 4th gear from low RPM to approximately 3,000 RPM, then decelerate using engine braking. Repeat this process for 10-15 cycles.
  • Monitor clutch engagement. If the clutch shudders or vibrates during engagement, it may indicate glazing or improper alignment. Address any issues immediately.

Track Testing

Once break-in is complete, verify the system under controlled conditions.

  • Dyno testing: Use a chassis dynamometer to confirm power output and check for driveline noise or vibration. Monitor transmission oil temperature during the run.
  • Data logging: Log gear position, throttle position, RPM, and speed during a test drive. This helps identify shifting issues or slipping ratios.
  • Inspect for leaks: Check the transmission, transfer case, and clutch line for fluid leaks after each test session. Even a small leak can lead to catastrophic failure.

Common Issues and Troubleshooting

Even with careful installation, problems can arise. Here are common issues and how to address them:

  • Difficult engagement or grinding. Check clutch hydraulic system for air or contamination. Re-bleed the system. If the problem persists, inspect the clutch fork and pivot for binding or damage.
  • Vibration at high RPM. This is often caused by driveline angle misalignment. Check the transmission mount, engine mounts, and rear diff bushing for wear or incorrect orientation.
  • Transmission whine. A constant whine in 3rd, 4th, or 5th gear may indicate gear contact pattern issues. This is common with aftermarket helical gear sets. If the noise is excessive, consult the gear manufacturer.
  • Clutch slip under load. This usually indicates insufficient clamping force or glazed discs. Confirm that the clutch is properly rated for your torque level and that the break-in procedure was followed.

Cost Considerations and Priorities

A 700 hp reliable transmission build is not inexpensive. Budget accordingly.

  • Clutch kit: $1,200–$3,500 (OS Giken R2C or Exedy Hyper Twin)
  • Billet gear set: $3,500–$6,000 (OS Giken or PPG)
  • Synchro kit: $400–$1,000 (Nismo or OS Giken)
  • Short shifter and bushings: $200–$600
  • Transfer case upgrades: $800–$2,000 (chain, bearings, cooler)
  • Installation labor: $1,500–$4,000 (professional shop rates)
  • Miscellaneous (bolts, fluids, gaskets): $200–$500

A complete budget for a reliable 700 hp transmission should be approximately $8,000–$18,000 depending on the level of upgrades and labor costs. Cutting corners on the gear set or clutch often results in failure that costs more to repair than the initial upgrade.

Conclusion

Upgrading the R33 GT-R transmission for 700 horsepower stability is a well-understood process that requires careful component selection, meticulous installation, and disciplined testing. A properly built driveline with a twin-plate clutch, billet gear set, strengthened synchros, and upgraded transfer case components will provide the reliability needed to enjoy this legendary car at its full potential. Whether you are building a street-driven weekend toy, a time attack monster, or a drag strip contender, investing in the right transmission modifications ensures that the power reaches the ground without drama or failure. The R33 GT-R remains one of the most capable platforms ever produced, and with the right upgrades, a 700 hp example can be both exhilarating and dependable for years to come.