The Nissan GT-R R35 is celebrated for combining exotic-car performance with surprising daily-driver usability. Its twin-turbocharged VR38DETT engine responds exceptionally well to modifications, and among the most transformative upgrades is a turbocharger swap. The Garrett G35-900 has emerged as a standout choice for GT-R owners seeking a substantial power increase without sacrificing drivability. This article takes an in-depth look at the power gains achievable with the Garrett G35-900 turbocharger on a Nissan GT-R R35, the supporting modifications required, and the investment of roughly $8,500 to bring the package together.

Understanding Turbocharger Upgrades

Turbochargers increase engine power by compressing intake air, allowing more oxygen to enter the combustion chamber. More oxygen enables a larger fuel charge, leading to a more powerful explosion and, ultimately, greater horsepower and torque. The GT-R's stock turbos are efficient for the factory power level (around 480–545 hp depending on year), but they quickly become a bottleneck when boost and airflow demands rise. Upgrading to a larger, more efficient turbocharger like the Garrett G35-900 unlocks the VR38DETT's potential by reducing backpressure and delivering higher mass airflow at lower pressure ratios. This means you can achieve significantly more power with less boost, reducing heat soak and stress on the engine.

The choice of turbocharger matters: a unit that spools too late may make the car feel sluggish off the line, while one that flows inadequately caps top-end power. The G35-900 strikes a strong balance for the GT-R platform, offering quick spool relative to its output capacity and maintaining a broad power curve.

The Garrett G35-900: A Closer Look

Garrett Motion’s G-series turbos, launched in 2018, represent a significant leap in turbocharger technology. The G35-900 is specifically designed for high-horsepower street and track applications, combining cutting-edge aerodynamics with robust construction. It is a single-scroll turbocharger but is often used in twin configurations on the GT-R (two G35-900s are required for the V6).

Key Specifications

  • Compressor Wheel: 60.5mm inducer / 76.5mm exducer — Garrett’s airfoil technology (integrated compressor cover with a stub-less hub) reduces turbulence and increases efficiency.
  • Compressor Housing: “F1-spec” profile with a ported shroud design for increased airflow and surge margin.
  • Turbine Wheel: 58mm inducer / 63mm exducer — made from MarM 247 superalloy for high-temperature durability.
  • Turbine Housing: Available in dual-entry (T4 twin-scroll), T4 divided, or V-band configurations. For the GT-R R35, the recommended housing is typically a twin-scroll T4 flange to match the factory twin-turbo exhaust routing, though custom setups often use divided T4 or T6 singe housings with twin scroll gates.
  • Maximum Power Capability: Approximately 900 hp per turbo (interwheel rating). In a twin setup on the GT-R, total engine output can exceed 1,000 whp with proper supporting mods, but the “900” label refers to the unit’s capability range (700–900 hp combined).
  • Spool Characteristics: On a built GT-R 3.8L, twin G35-900s can achieve full boost (25–30 psi) by 3,800–4,200 rpm, depending on housing A/R and cam timing. This represents a only a modest increase in lag compared to factory turbos, while providing massive flow up top.

The G35-900 also features Garrett’s exclusive “dual ball bearing” cartridge, which reduces friction and supports faster spool, and integrated boost actuation options (WG40 or WG45 wastegate ports). For the GT-R, aftermarket external wastegates (often 44mm or 45mm) are recommended to precisely control boost.

For comparison, the larger G35-1050 shifts the power band higher and trades some spool speed for ultimate horsepower, while the smaller G25 series offers faster spool but lower peak flow. The G35-900 sits in the “sweet spot” for GT-R owners targeting 700–850 whp on pump gas or 900+ whp on race fuel or methanol.

Power Gains and Dyno Results

Actual power gains depend heavily on fuel quality, boost pressure, and whether the car uses E85, race gas, or pump 93 octane. With a full bolt-on GT-R and twin G35-900 turbos, typical results from reputable tuners are as follows:

  • On 93 OCT or similar (21–23 psi): 700–750 whp / 680–720 lb-ft torque
  • On E85 (25–28 psi): 780–850 whp / 740–800 lb-ft torque
  • On race gas (30+ psi): 850–950 whp / 800+ lb-ft torque

To put this in perspective, a stock GT-R (2009–2012) puts down around 440–470 whp. Even with simple bolt-ons and a tune, reaching 600 whp is possible. The G35-900 twin upgrade more than doubles that output. Dyno sheets from shops like AMS Performance show smooth power curves with minimal dip between torque peaks — a testament to the turbo’s efficient flow.

Dynojet example: A 2013 GT-R with twin G35-900s, 1300cc injectors, dual walbro 525 pumps, Cobb flex fuel kit, and full exhaust made 822 whp and 790 lb-ft on E85 at 27 psi. The curve peaked at 6,800 rpm and still held 740 whp at 7,500 rpm.

Boost response on the street is impressive: in 3rd gear, boost builds to 20 psi by 4,000 rpm, and full boost arrives soon after. This makes the car usable on the highway and fun at the drag strip without the lag associated with larger turbos like the G35-1050 or G42-1450.

Supporting Modifications for Optimal Performance

Installing twin G35-900 turbos without upgrading the rest of the system is a recipe for disaster. The VR38's fuel system, intake, exhaust, and cooling must match the increased airflow. Here are the essential supporting modifications:

Fuel System

Stock fuel injectors (around 440cc for early cars) are grossly inadequate. For any G35-900 setup, you need at least 1,000cc injectors (often 1,200cc or 1,300cc on E85). Fuel pumps: a single in-tank Walbro 525 is the minimum; many shops use dual pumps (one in tank, one inline) to supply the volume required for 800+ whp. A fuel pressure regulator and lines (e.g., -10AN feed, -8AN return) are mandatory.

Intercooler

The stock intercooler charge-air system can handle 600 whp but quickly heat soaks above that. An aftermarket step-up intercooler (such as Treadstone or AMS) with larger core volume reduces intake temperatures by 20–30°F, allowing more consistent power. Many G35-900 builds also upgrade to custom aluminum hard pipes to reduce boost losses.

Exhaust System

Stock exhaust manifolds (downpipes) and mid-pipe restrict flow on high-power builds. Upgrade to stainless steel or inconel downpipes with a 3-inch or 3.5-inch catless exhaust. A full Ti exhaust saves weight, but bare minimum is a high-flow cat system (if emissions are a concern).

Engine Management and Tuning

The GT-R’s ECU can be reflashed by specialists like Cobb Tuning (Accessport), ECUtek (MoTeC based), or standalone systems (e.g., Syvecs). Professional tuning on a chassis dyno ensures the turbos operate safely within the knock limit and fuel trims. It is not recommended to throw turbos on without a custom tune — instant engine damage will occur.

Other Essentials

  • Clutch or Torque Converter: Stock GT-R clutches slip around 650 whp. A triple-plate clutch or high-stall torque converter (for automatic transmission cars) is needed.
  • Transmission Cooling: The GR6 dual-clutch trans generates significant heat; upgraded coolers and possibly a transmission rebuild with stronger gears are needed for sustained track use.
  • Boost Control: Use dual manual boost controllers or a boost-tuned turbo smart eBoost2, plus external wastegates (44mm for twin setups).

Cost Breakdown and Value

The often-quoted $8,500 investment for the G35-900 upgrade is a rough baseline covering turbos, installation labor, and basic tuning. However, a comprehensive build that includes all supporting modifications will cost more. Realistic budget:

  • Twin Garrett G35-900 turbos (with T4 housings): $4,200–$4,800 (pair)
  • Installation labor: $1,500–$2,500 (shop time, typically 20–30 hours)
  • Professional dyno tuning: $1,200–$1,800
  • Supporting modifications (fuel, intercooler, exhaust, etc.): $3,000–$5,000 depending on brands
  • Miscellaneous (gaskets, fluids, fittings): $500–$1,000

Total range: $10,400–$15,100 for a complete turnkey package. The $8,500 figure likely assumes you already have some bolt-ons (e.g., exhaust, intercooler) and provides just the turbos plus install and tune. If you are starting from stock, budget closer to $12,000–$14,000.

Value perspective: For that investment, you gain 300–500 whp over stock — that’s roughly $25–$30 per horsepower, which is competitive in the aftermarket world. Moreover, the G35-900s offer room to grow: with cams, ported heads, and a built bottom end, the same turbos can support over 1,000 whp.

Installation Considerations

Installing twin G35-900s on a GT-R is not a weekend project for a DIY enthusiast without a well-equipped shop. The engine bay is tight; removing the factory turbos requires unbolting the front differential, subframe droop, and sometimes pulling the engine halfway. Professional installation is strongly recommended. Common pitfalls:

  • Oil supply and drain lines must be properly sized; the GT-R uses a sealed oil system with a scavenge pump on the stock turbos. Aftermarket turbos require you to tap the oil pan for new drains or use a reservoir.
  • Water lines: many delete the stock water cooling on the turbos to simplify plumbing — acceptable if you allow proper cool-down after hard runs.
  • Wastegate placement: avoid interfering with the subframe. Custom fabrication may be needed.
  • Downtime: typical shop turn-around is 2–4 weeks.

If you are considering a self-install, ensure you have a lift, torque wrench, and patience. Several online forums like GT-R Heritage have detailed build threads.

Tuning and Calibration

The G35-900’s efficiency bands require a tuner who understands the twin-turbo VR38. Do not use a generic “off-the-shelf” map. The tuner will adjust boost curve, spark advance, cam timing (if using VVEL or variable cam gears), and fuel trims. A typical dyno session takes 3–5 hours. On AWD dynos, ensure the operator has experience with the GT-R’s ATTESA-ETS system, as improper strapping can skew results. Tuning on E85 is recommended for maximum safety and power; the cooling effect of ethanol reduces knock tendency and allows more aggressive timing.

Potential Risks and Reliability

While the G35-900 is robust, any 800+ whp build stresses the engine and drivetrain. Risks include:

  • Engine Failure: Stock pistons and rods can tolerate 800–850 whp with a conservative tune, but detonation or high cylinder pressure can quickly break a piston. For sustained 900+ whp, forged internals (CP-Carrillo rods, JE pistons) are necessary.
  • Transmission Breakdown: The GR6 gearbox is the weak link. Even with upgraded clutches, the 3rd and 4th gear hubs can shear. Many high-power GT-Rs run dog-engagement gear sets or PPG sequential conversions.
  • Heat Management: The VR38 runs hot. Additional oil coolers, a larger radiator, and hood vents or a vented carbon bonnet help keep underhood temperatures manageable.
  • Boost Control Issues: If wastegates are too small or boost controllers not properly calibrated, you risk overshoot that can cause detonation. Use high-quality gates (Tial, Turbosmart) and log boost carefully.

To mitigate risks, perform regular oil analysis, inspect wastegate diaphragms, and consider a built engine if you intend to track the car frequently at full power.

Conclusion

The Garrett G35-900 turbocharger upgrade for the Nissan GT-R R35 is one of the most effective ways to unlock the engine’s latent performance. With realistic power gains of 700–900 whp (depending on fuel and boost level), a well-chosen supporting package, and professional tuning, the GT-R transforms into a supercar-slaying machine. The $8,500–$15,000 investment — while significant — yields a power-per-dollar ratio that few other modifications can match. For enthusiasts who can handle the higher maintenance and drivetrain demands, the G35-900 package delivers thrilling acceleration, robust reliability, and a driving experience that justifies its status as a benchmark turbo upgrade for the legendary GT-R.