The Nissan R32 GT-R, often called "Godzilla," remains one of the most celebrated performance cars in automotive history. Its RB26DETT engine, advanced all-wheel-drive system, and balanced chassis set a benchmark in the early '90s. However, when enthusiasts aim for 700+ horsepower—a common threshold for streetable track monsters—the factory drivetrain quickly reaches its limits. Achieving reliable, usable power at this level demands a methodical approach to upgrading every link in the power delivery chain. This guide breaks down the essential components, upgrades, and considerations for building a drivetrain that can handle 700+ hp without compromising durability or drivability.

The RB26DETT: Building a Strong Foundation for 700+ HP

The stock RB26DETT is a robust 2.6L inline-six, but its factory internals and turbochargers were designed for around 280 hp (the Japanese gentleman's agreement). To reach 700+ hp reliably, the engine must be comprehensively built. While many focus solely on larger turbos, neglecting the bottom end, valvetrain, and fuel system leads to premature failures.

Bottom End Strengthening

The factory cast pistons and connecting rods are the first weak links. At power levels above 500-600 hp, they can crack or bend under sustained boost. For 700+ hp, aftermarket forged pistons (e.g., CP-Carrillo, JE, Wiseco) and forged connecting rods (e.g., Carillo, Pauter, Manley) are mandatory. These components handle higher cylinder pressures and provide safety margins for occasional spikes. Additionally, upgrading to ARP head studs and main studs prevents head lift and bearing walk at elevated boost levels.

Turbocharging Options

Choosing the right turbo setup defines power delivery. Common options for 700+ hp include:

  • Single Turbo Conversions: A large single turbo like a Garrett G42-1200 or BorgWarner S480 simplifies plumbing and spools harder but may sacrifice low-end responsiveness. With proper manifold design (e.g., a divided T4 flange), 700 hp is achievable with excellent mid-range torque.
  • Big Twins: Twin T51R or GT3582R turbos retain a more stock-like spool characteristic but require complex exhaust manifold and intercooling setups. Tuners often prefer twins for street cars aiming for 800+ hp, as they keep the throttle response sharper.
  • Hybrid Stock-Frame Turbos: Some builders use high-flow Garrett or BorgWarner turbos that bolt onto the factory manifold positions. These can support 650-750 hp with upgraded wastegates and exhausts but are less common due to packaging limits.

Whichever route, external wastegates (Tial 44mm or 60mm) and a high-quality blow-off valve (HKS SSQV, Turbosmart) are necessary to control boost precisely and prevent compressor surge.

Fuel System & ECU

700 hp requires a corresponding fuel delivery system. Start with an in-tank surge tank or a high-flow lift pump feeding a dedicated swirl pot and a second external pump (e.g., Aeromotive A1000, Walbro 450). Injectors of 1000cc or higher (ID1700x, Injector Dynamics) are typical, along with a fuel pressure regulator (FPR) capable of handling 70-80 psi. The factory ECU cannot manage these setups; a standalone unit like a Haltech Elite 2500, Link G4+ Fury, or MoTeC M130 is essential for tuning fuel, ignition, and boost control strategies.

The R32 GT-R's stock manual transmission (Getrag 5-speed) is notorious for breaking at power levels above 400-500 hp, especially during aggressive launches or high-speed shifts. The gear sets, synchros, and shift forks simply weren't designed for the torque loads of a 700+ hp engine. Several upgrade paths exist.

Option 1: Stock Gear Set with Billet Components

For cars staying below 800 hp, some shops offer billet steel gear sets (e.g., PPG, Albins, PAR Engineering) that replace the factory gears. These provide a significant strength increase, though the case may still flex under extreme loads. Adding a reinforced bearing plate and upgraded synchros (carbon or brass) improves shift feel. This option is relatively affordable but still requires annual inspections.

Option 2: Sequential / Dog Box Gear Sets

A dog engagement gearbox (e.g., PPG helical or straight cut, Hollinger, Samsonas) eliminates synchros and allows full-throttle upshifts. These gearboxes are preferred for dedicated track cars because they handle 1000+ hp reliably and reduce shifting time. The trade-off is noise, drivability at low speeds, and higher maintenance costs. For a street car that sees occasional track days, a synchromesh gear set (like PPG's "RT" series) offers a compromise.

Clutch and Flywheel

A performance clutch must handle the torque while providing acceptable pedal feel. Twin-disc and triple-disc clutches (e.g., OS Giken, Exedy Hyper Twin, Competition Clutch) provide high torque capacity (800-1200 ft-lb) without the heavy pedal of single-plate sprung clutches. Lightweight chromoly or aluminum flywheels reduce rotational inertia, improving throttle response but may increase gear noise at idle. Choose a clutch rated for at least 20% above your expected peak torque.

Driveshaft & Axles: Transferring Power Without Twist

The factory steel driveshaft is surprisingly durable, but at 700+ hp, its weight and vibration limits become apparent. Upgrading to a one-piece carbon fiber driveshaft (e.g., from The Driveshaft Shop or QA1) reduces driveline inertia and allows higher critical speeds, reducing the risk of catastrophic failure at high RPM. For sedate street cars, an aluminum shaft (Mark Williams, Strange) is an affordable alternative. Always ensure proper balancing and alignment—driveline angle changes from suspension drops or subframe shifting can cause vibrations that destroy bearings and seals.

The R32 GT-R's rear axles are hollow and splined, and they often snap under hard launches with sticky tires. Upgrade to billet steel or chromoly axles (e.g., DSS Level 5, Raxles) with upgraded CV joints. Many builders opt for a "C-V Joint" conversion using high-angle joints from The Driveshaft Shop to accommodate lowered suspensions and eliminate wheel hop.

Differential: Distributing Torque to All Four Wheels

The R32 GT-R uses an ATTESA E-TS Pro system with an electronically controlled center differential and a viscous-coupled rear LSD. For 700+ hp, the stock rear differential cannot handle sustained power and heat. Upgrading to a carbon disc limited-slip differential (e.g., OS Giken Superlock, Cusco RS, NISMO LSD) provides lock-up under acceleration, improving traction and stability. The center differential itself is robust, but many builders replace it with an upgraded billet unit (Nismo, ATS) to strengthen the clutch packs and response times. The front differential is generally adequate for 700 hp, but upgrading to a helical LSD (Kaaz, Quaife) reduces understeer during corner exit.

Supporting Modifications for Reliability

A 700+ hp drivetrain is only as good as its supporting systems. The following upgrades are mandatory for consistent performance and safety.

Suspension & Bushings

Power increase requires better chassis control. Upgrade to adjustable coilovers (e.g., Ohlins R&T, KW V3, TEIN Super Street) with higher spring rates (12k-14k front, 10k-12k rear). Replace worn rubber bushings with polyurethane or spherical bearings (Whiteline, SuperPro, Hardrace) to reduce deflection and maintain alignment. Lowering the car too much stresses CV joints and changes roll centers—aim for a modest drop (20-30 mm) and upgrade rear suspension arms for camber and toe adjustment.

Brakes

Stopping 3,200+ lbs of GT-R at high speed demands big braking. A front big brake kit (BBK) with 355-380mm rotors and 6-piston calipers (e.g., Brembo GT-R, AP Racing, StopTech Trophy) provides fade-free performance. Replace the rear calipers with upgraded 4-piston units (e.g., R33 GT-R OEM, Brembo) and use track-focused pads (Ferodo DS2500, Pagid RS29) with high-temperature brake fluid (Motul RBF660, Castrol SRF). Stainless steel braided brake lines improve pedal feel.

Tires

All the power in the world means nothing without grip. Use high-performance summer tires (Michelin Pilot Sport 4S, Yokohama Advan A052) in 245-265 width on the front and 285-315 on the rear. For track use, consider semi-slicks like Nankang AR-1 or Hoosier R7. Proper wheel width (9.5J front, 10.5J rear) and offset ensure tire clearance and avoid rubbing.

Common Pitfalls & Budget Considerations

Building a 700+ hp R32 GT-R drivetrain is expensive. Expect to invest $15,000–$25,000 for a complete built transmission, differentials, axles, and driveshaft, not including engine and tuning. Common mistakes include:

  • Neglecting cooling: Oil coolers (for engine, transmission, differential) prevent heat soak and component wear. Install a large oil cooler (Setrab, Earl's) with a thermostatic plate and an upgraded radiator (Koyo, Mishimoto).
  • Skipping driveline alignment: After suspension changes, verify pinion angle and driveshaft phasing. A misaligned driveline can cause vibration and ruin U-joints or bearings.
  • Overlooking wheel hop: Wheel hop destroys axles and differentials. Subframe bushing inserts (Whiteline, Hardrace) and upgraded engine/transmission mounts (Nismo, Cusco) reduce movement during hard launches.
  • Using a stock fuel tank without surge: The factory saddle tank can starve the pump under lateral G. A surge tank or baffled custom tank (e.g., Radium, Aeromotive) is essential.

Conclusion

Building a drivetrain for the Nissan R32 GT-R capable of reliably handling 700+ horsepower is not a simple bolt-on affair—it is a fully integrated upgrade of the engine, transmission, driveline, and supporting systems. Each component must be chosen to work in harmony, from forged pistons and large turbos to a dog-box transmission and billet axles. With careful planning, proper installation, and professional tuning, the result is a car that not only delivers awe-inspiring power but also instills confidence on the street or track. The R32 GT-R legend lives on when its drivetrain is built to match its iconic heritage.

For further reading and product sourcing, consult these resources:

  • Garage Whifbitz – Specialists in RB26 engine builds and drivetrain upgrades.
  • R35 Performance – Turbos, fuel systems, and custom parts for GT-Rs.
  • The Driveshaft Shop – Carbon fiber driveshafts and high-performance axles for R32 GT-R.
  • SAU Forums – Community builds and technical discussions on R32 GT-R performance.