Boost Lab services the full Nissan GT-R turbocharger spectrum: from OEM IHI RHF55 rebuild on stock turbos to hybrid stock-location upgrades to full large-frame turbo kit service. Both turbos rebuilt as a matched pair, every time. All chassis codes covered.
The Nissan R35 GT-R uses a pair of IHI RHF55 turbochargers on the VR38DETT 3.8L twin-turbocharged V6. Notably, the RHF55 is the same turbocharger platform used on the Subaru STI (MY06): a shared architecture between two of the most iconic all-wheel-drive performance platforms of their era.
The two turbos are mirror images of each other, left (driver side) and right (passenger side), with separate OEM part numbers. Both units must be rebuilt as a matched pair. Differential wear between left and right is common on GT-Rs, particularly on cars that have seen track use or sustained high-boost operation. The passenger-side turbo typically shows more wear due to differences in oil drainage geometry and heat exposure.
The stock turbos use a floating metal bearing, not ball bearing, at the factory. This is an important distinction when sourcing rebuild components and when considering upgrade paths. Ball bearing CHRAs are available as an upgrade at rebuild time and offer improved response and longevity under sustained high-boost use.
The OEM turbo assembly on 2009-2019 models is integrated into a one-piece "turbofold," a combined turbine housing and exhaust manifold unit. This design keeps packaging tight but makes larger turbo upgrades more complex. The 2020+ model year introduced a two-piece design that separates the manifold from the turbine housing, significantly simplifying turbo swaps.
| Specification | Value |
|---|---|
| Turbo Platform | IHI RHF55 |
| Configuration | Twin (L + R mirror) |
| Compressor Wheel | 60mm / 46.5mm inducer |
| Turbine Wheel | 53mm / 48mm |
| Compressor Blades | 6 + 6 |
| Turbine Blades | 11 |
| Max Turbine Speed | 165,000 RPM |
| Bearing Type | Floating metal (BB upgrade available) |
| Wastegate | Pneumatic actuator |
| Left OEM PN | 14411-JF00A / KB40A |
| Right OEM PN | 14411-KB50A |
| IHI Designation | IHI455 (L) / IHI456 (R) |
The R35 GT-R went through several factory power increases across its production run. The chassis code prefix indicates the emissions standard and generation.
The original R35 generation. Stock IHI RHF55 pair. One-piece turbofold integrates the turbine housing with the exhaust manifold. Turbo upgrades on CBA cars require new manifolds/turbofolds from the kit manufacturer since the OEM one-piece unit cannot accommodate larger CHRAs without machining. CBA cars are often upgraded to DBA-spec inlet pipes at the same time as a turbo service.
The DBA (2012-2016) introduced factory power increases through revised intake manifolds, larger intercooler ducting, sodium-filled exhaust valves, and revised ECU mapping. The 2017-2019 facelift maintains the DBA chassis code with additional cosmetic and NVH changes, boosted to 562hp. Still uses the one-piece turbofold, so same upgrade considerations as CBA for full kit installations. Most popular generation in the used market.
The 2020 model year introduced the most significant turbo architecture change in R35 history: a two-piece design separating the exhaust manifold from the turbine housing. This makes turbo swaps significantly more straightforward since the turbine housing can be removed and replaced independently of the manifold. 2020+ owners should confirm with their kit supplier which manifold provisions are required for their specific upgrade choice before ordering.
The NISMO and Track Edition models use uprated IHI RHF55 variants with higher-flow compressor and turbine wheels than the standard car. NISMO turbos use different OEM part numbers (14411-JF40A left, separate right PN) and should be identified correctly at teardown. NISMO turbos are often used as mild upgrades on standard DBA cars due to their higher flow capacity within the stock housing architecture.
Boost Lab services GT-R turbos across the full power spectrum. Whether you need a precision OEM rebuild or service on a large-frame turbo kit, we have the equipment and experience.
Stock power, up to ~600whp on supporting mods. A precision rebuild of the factory IHI RHF55 pair to OEM specification. New bearings, seals, thrust components, and a full cleaning of all oil and coolant passages. VSR balanced before leaving the shop. Ball bearing upgrade and billet compressor wheel upgrade both available at rebuild time. The stock turbos are capable of approximately 580-600whp at their limit regardless of supporting modifications.
~700whp to ~1,100whp depending on spec. Hybrid stock-location turbos use the OEM turbofold housing machined to accept a larger CHRA with upgraded compressor and turbine wheels. The result bolts in like stock but flows significantly more. The most popular upgrade path for street GT-Rs. We service all major hybrid platforms: Pure Turbos Pure1000, AAM Competition GT1000-R, Boost Logic 750X Gen 2, Forced Performance, Xona, and custom CHRA upgrades.
~900whp to 2,200whp+. Full replacement kits use new manifolds, turbofolds, and purpose-built turbochargers. We service, rebuild, and VSR balance every major kit platform: AMS Alpha/Omega Series (Alpha 9 through 22X, Omega 9 through 14), ETS Stock-Location Kits (GTX28 through GTX3582R Gen 2), Speed By Design SBD900R, Precision Turbo kits (PT6266 through PT8285), and all Garrett, BorgWarner, and Xona units.
The left and right turbos on the VR38DETT are not perfectly symmetrical in their operating environment. Oil drainage geometry, heat exposure, and exhaust pulse characteristics differ slightly between the two banks. On high-mileage or heavily used GT-Rs the passenger-side turbo typically shows more wear. Always rebuild both turbos together; replacing only the failed unit and leaving the worn twin creates an imbalanced system that puts extra load on the rebuilt turbo.
The VR38DETT is a high-strung engine running significant boost from the factory. Any internal engine event, a spun bearing, piston ring failure, or valve seal failure, sends contaminated oil through the turbo bearing housing. A GT-R that has had any internal engine work done should have both turbos inspected before returning to service.
The stock IHI RHF55 uses a floating metal bearing, reliable at factory boost levels but showing its limits on cars running significantly above OEM boost targets on supporting modifications. Sustained high-boost operation on the stock floating bearing accelerates wear compared to a ball bearing CHRA. Cars running stage 2 or above on the stock turbos should be inspected periodically rather than waiting for audible symptoms. A ball bearing upgrade at rebuild time is the standard recommendation for any tuned GT-R staying on stock-location turbos.
The OEM RHF55 compressor map has defined flow limits. GT-Rs running aggressive tunes that push the stock turbos beyond their efficient operating range experience compressor surge, a cyclical stall condition that hammers the thrust bearing and fatigues the compressor wheel. This is common on cars that have been tuned hard on stock turbos before a planned upgrade. Surge presents as a distinctive chuffing or fluttering sound under boost.
Track use followed by an immediate shutdown is a common pattern on GT-Rs and one of the more preventable causes of turbo bearing damage. Residual heat in the turbine housing cooks oil in the bearing housing with no oil flow. A cooldown idle of 2-3 minutes after any track session significantly extends turbo bearing life.
Intake-side FOD from deteriorated silicone couplers, loose hardware, or failed air filters contacts the compressor wheel at operating speed. On a high-RPM, high-boost GT-R application the consequences of even small debris reaching the compressor wheel are significant. Compressor wheel condition and turbine wheel condition are both documented at teardown with photos before any rebuild quote is issued.
Stock rebuild or full upgrade service: start a rebuild request and ship your turbos to Dade City, FL. Both units processed together.
Start Your Rebuild37833 Pineapple Ave Unit A • Dade City, FL 33523 • sales@theboostlab.com