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IHI Turbocharger Rebuild Service

IHI Turbo Rebuild

Complete in-house rebuild service for IHI turbochargers. Subaru VF series from VF22 through VF60, Ferrari F40 and 488, Porsche Cayenne, GM Duramax, and the full range of IHI OEM applications. Ball bearing and journal bearing. In-house VSR balancing since 2008.

VF22through VF60+ BB + JBBoth Bearing Types VSRIn-House Balancing
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Subaru WRXVF52 VF54 VF57
Subaru STIVF48 VF39 VF43 VF49
JDM PerformanceVF34 VF36 VF37 VF38
Other PlatformsPorsche Cayenne / Duramax / Ferrari
Bearing TypesBall Bearing + Journal Bearing
In Shop Since2008, 17+ years
VF Series Reference

IHI VF Series Decoded

IHI uses the VF designation across the Subaru performance lineup. The VF number does not follow a simple size progression; it reflects the specific combination of compressor housing, turbine housing, and bearing type built for a particular Subaru application. Two turbos with consecutive VF numbers can have entirely different performance characteristics.

IHI uses two bearing systems across the VF lineup. Ball bearing units spool faster and are generally found on higher-spec JDM applications and later USDM turbos. Journal bearing units are common on earlier USDM WRX and some STI applications. Both are fully supported at Boost Lab.

ModelSubaru OEM #BearingScrollApplication
VF2214411AA070BallSingle P20JDM WRX / STI EJ20 early, largest flow VF
VF2314411AA130BallSingle P20JDM WRX EJ20, large housing small wheel
VF2414411AA150BallSingle P18JDM WRX EJ20 / Rally / automatic
VF2814411AA200BallSingle P20JDM STI Version 5 EJ207
VF2914411AA220BallSingle P18JDM WRX EJ20 improved compressor wheel
VF3014411AA373JournalSingle P18JDM STI EJ20, popular budget option
VF3414411AA340BallSingle P18JDM STI EJ207, same size as VF30 BB
VF3514411AA443JournalSingle P15JDM WRX Type RA, fast spool small housing
VF3614411AA490BallTwin P25JDM STI Spec C 2003+, Ti shaft twin scroll
VF3714411AA542JournalTwin P25JDM STI V8/V9 Spec-C EJ207 twin scroll
VF3814411AA560BallTwin P18JDM Legacy GT, fast spool Ti turbine shaft
VF3914411AA572JournalSingle P18USDM STI 2004-2006 EJ257
VF4014411AA530JournalSingle P18USDM Legacy GT 2005-2007 EJ255
VF4114411AA610JournalSingle P18JDM Forester STI EJ207
VF4314411AA620JournalSingle P18USDM STI 2007 EJ257, larger wastegate than VF39
VF4514411AA650JournalSingle P18JDM WRX / Legacy EJ20 2004+
VF4814411AA700JournalSingle P18USDM STI 2008-2021 EJ257 / EJ257B
VF4914411AA690JournalTwin ScrollJDM STI 2008-2014 EJ207 twin scroll
VF5214411AA800JournalSingle P18USDM WRX 2009-2014 EJ255
VF5414411AA760JournalSingle P18USDM Legacy GT 2008-2012 EJ255
VF5714411AA830JournalSingle P18USDM WRX 2015-2021 FA20DIT (turbo frame only)
VF6014411AA900JournalSingleSubaru Levorg / BRZ tS JDM applications
Platform Coverage

Every IHI Platform We Rebuild

IHI supplies turbochargers to Subaru, Porsche, GM, Ferrari, and a wide range of OEM automotive and diesel applications globally. We rebuild all of them. The Subaru VF lineup is our highest IHI volume but no platform is excluded.

Subaru WRX

VF52, VF54, VF57, TD04L

The USDM WRX runs IHI from 2008 onward with the VF52 being the most common rebuild unit. The 2002-2007 WRX uses the Mitsubishi TD04L (see our MHI page for those). From 2008 the WRX received the VF52 (2009-2014 EJ255), VF54 on Legacy GT (2008-2012), and VF57 on the FA20DIT-powered 2015+ WRX. The VF52 is a journal bearing single scroll unit capable of 300+ WHP with supporting modifications and proper fueling. Oil starvation from the Subaru banjo bolt restriction is the most common rebuild cause on all WRX IHI units.

Applications: 2009-2014 WRX (VF52) / 2015-2021 WRX FA20DIT (VF57) / 2008-2012 Legacy GT (VF54)

Subaru STI

VF39, VF43, VF48, VF49

The USDM STI has run IHI VF series turbos through its entire US production life. VF39 on the 2004-2006 STI, VF43 on 2007 (with an enlarged wastegate), and VF48 on the 2008-2021 EJ257 STI. All three are journal bearing single scroll units on the RHF55 frame. The VF48 is the most common STI rebuild unit we see. JDM STI owners with VF49 (twin scroll, journal) and VF36/VF37 (twin scroll) units are also fully supported.

Applications: 2004-2006 STI (VF39) / 2007 STI (VF43) / 2008-2021 STI (VF48) / JDM STI EJ207 (VF36, VF37, VF49)

JDM Performance

VF22, VF34, VF36, VF38

The JDM VF lineup covers the EJ20 and EJ207 performance variants used in JDM WRX, STI, Legacy GT, and Forester STI applications. The ball bearing units (VF22, VF23, VF24, VF28, VF29, VF34, VF36, VF38) deliver faster spool than their USDM journal bearing counterparts. VF36 and VF38 introduced titanium turbine shafts for reduced inertia. VF36 uses a twin scroll housing unique to the Spec C STI. These units are increasingly imported and we rebuild all configurations.

Applications: JDM WRX EJ20 / JDM STI EJ207 / JDM Legacy GT / JDM Forester STI / JDM Impreza STI imports

Legacy GT / Forester XT

VF40, VF41, VF45, VF54

The EJ255 Legacy GT and Forester XT platforms use dedicated VF variants tuned for their specific boost and power targets. VF40 on 2005-2007 USDM Legacy GT, VF54 on 2008-2012 USDM Legacy GT, VF41 on JDM Forester STI, and VF45 on JDM WRX. The Legacy GT applications frequently come in with oil contamination and coking from the longer oil passages on the horizontally-opposed engine in a sedan application. Rebuild process and turnaround are identical to WRX and STI units.

Applications: 2005-2012 Subaru Legacy GT / 2004-2008 Forester XT / JDM Legacy / JDM Forester STI

Porsche Cayenne

RHF5H, VVQ1, VVQ2

The first-generation Porsche Cayenne Turbo (2003-2007, 948 engine, 4.5L V8 twin turbo) uses IHI RHF5H units. Two turbos per car, identified by IHI part codes VVQ1 and VVQ2. Journal bearing water-cooled units. Common failures are oil coking from the extreme heat environment in the Cayenne engine bay and bearing wear from extended oil intervals on a high-performance V8 twin turbo platform that many owners treat as a daily driver. Both turbos should be rebuilt together when either fails.

Applications: 2003-2007 Porsche Cayenne Turbo 4.5L V8 (955 platform), IHI VVQ1 and VVQ2 twin turbo set

GM Duramax LB7

RHF5, 8973077111

The 2001-2004 6.6L Duramax LB7 uses an IHI RHF5 turbocharger as OEM equipment. The LB7 Duramax is known for injector failures, and when those fail they push excessive fuel into the cylinder, which washes the engine oil and damages the turbo through oil contamination and coking. Every LB7 IHI rebuild should verify the injector issue has been addressed before the rebuilt turbo goes back on the engine. The IHI RHF5 on the LB7 is a rebuildable unit and we stock the components for fast turnaround.

Applications: 2001-2004 GM 6.6L Duramax LB7 / Chevrolet Silverado 2500HD / 3500 / GMC Sierra 2500HD / 3500

RHF Series OEM

RHF3, RHF4, RHF5, RHF6, RHS, RHZ

The RHF series covers a wide range of OEM applications including Isuzu Trooper and Rodeo diesel (RHF5), various Daihatsu engines, early Subaru non-VF applications, Yanmar industrial, and KIA/Daewoo diesel platforms. The newer RHS and RHZ series are designed as interchangeable upgrades to the RHF line with improved aerodynamics and bearing design. Contact us with your nameplate part number if your application is not listed here.

Applications: Isuzu Trooper / Rodeo 4JB1T / 4JX1T / Daihatsu / Yanmar / KIA diesel / early Subaru / various OEM

Ferrari F40 and 488

RHB53LW, VU12B, VU13B, VU21, VU22

IHI supplies the turbochargers on two of the most significant Ferrari road cars ever produced. The Ferrari F40 (1987-1992) runs twin water-cooled IHI RHB53LW units on its Tipo F120A 2.9L V8. The IHI model codes are VU12B (left) and VU13B (right). The Ferrari 488 GTB, 488 Spider, 488 Pista, and F8 Tributo use IHI VU21 and VU22 twin turbos, both water-cooled ball bearing units designed for sustained high output. We have rebuilt both F40 and 488 turbos in-house. Contact us before shipping for any Ferrari IHI unit to confirm parts availability and turnaround.

Applications: 1987-1992 Ferrari F40 (VU12B / VU13B) / 2015-2020 Ferrari 488 GTB / Spider / Pista / F8 Tributo (VU21 / VU22)
VU12BVU13BVU21VU22
Part Number Reference

Find Your Part Number

Search by Subaru OEM part number, IHI VF model, IHI model code, or application. Subaru uses the 14411-XXXXXX format for all OEM turbo part numbers. IHI internal part numbers and model codes are stamped on the CHRA nameplate tag. If your number is not listed, contact us with the nameplate code and we can identify your unit.

Showing all 44 part numbers
Subaru / OEM Part #IHI ModelEngineApplicationNotes
Subaru WRX (USDM)
14411AA800VF52EJ255 2.5L2009-2014 Subaru WRX (USDM)Journal Bearing / Single Scroll
14411AA800DVF52EJ255 2.5L2009-2014 Subaru WRX (USDM)Journal Bearing / Single Scroll
Legacy / Forester / JDM
14411AA760VF54EJ255 2.5L2008-2012 Subaru Legacy GT (USDM)Journal Bearing / Single Scroll
14411AA760DVF54EJ255 2.5L2008-2012 Subaru Legacy GT (USDM)Journal Bearing / Single Scroll
Subaru WRX (USDM)
14411AA830VF57FA20DIT 2.0L2015-2021 Subaru WRX (USDM)Journal Bearing / Single Scroll
Subaru STI (USDM)
14411AA572VF39EJ257 2.5L2004-2006 Subaru STI (USDM)Journal Bearing / Single Scroll P18
14411AA620VF43EJ257 2.5L2007 Subaru STI (USDM)Journal Bearing / Larger Wastegate
14411AA700VF48EJ257 / EJ257B 2.5L2008-2021 Subaru WRX STI (USDM)Journal Bearing / Single Scroll P18
VA440057VF48EJ257 2.5L2008-2021 Subaru STI (USDM) alternateIHI Internal Code
VB440057VF48EJ257 2.5L2008-2021 Subaru STI (USDM) alternateIHI Internal Code
VC440057VF48EJ257 2.5L2008-2021 Subaru STI (USDM) alternateIHI Internal Code
JDM STI Twin Scroll
14411AA490VF36EJ207 2.0LJDM STI Spec-C 2003+, Ti shaft twin scrollBall Bearing / Twin Scroll P25
14411AA542VF37EJ207 2.0LJDM STI V8 / V9 Spec-C EJ207Journal Bearing / Twin Scroll P25
14411AA690VF49EJ207 2.0LJDM STI 2008-2014 EJ207 Twin ScrollJournal Bearing / Twin Scroll
14411AA070VF22EJ20 2.0LJDM WRX / STI EJ20 early, largest VFBall Bearing / Single Scroll P20
JDM Performance VF Series
14411AA130VF23EJ20 2.0LJDM WRX EJ20 large housing small wheelBall Bearing / Single Scroll P20
14411AA150VF24EJ20 2.0LJDM WRX EJ20 / Rally / automaticBall Bearing / Single Scroll P18
JDM STI Twin Scroll
14411AA200VF28EJ207 2.0LJDM STI Version 5 EJ207Ball Bearing / Single Scroll P20
JDM Performance VF Series
14411AA220VF29EJ20 2.0LJDM WRX EJ20 improved compressorBall Bearing / Single Scroll P18
JDM STI Twin Scroll
14411AA373VF30EJ207 2.0LJDM STI EJ20 single scrollJournal Bearing / Single Scroll P18
14411AA340VF34EJ207 2.0LJDM STI EJ207 ball bearing version of VF30Ball Bearing / Single Scroll P18
JDM Performance VF Series
14411AA443VF35EJ20 2.0LJDM WRX Type RA fast spool small housingJournal Bearing / Single Scroll P15
14411AA560VF38EJ20 2.0LJDM Legacy GT Ti shaft twin scrollBall Bearing / Twin Scroll P18
Legacy / Forester / JDM
14411AA530VF40EJ255 2.5LUSDM Legacy GT 2005-2007Journal Bearing / Single Scroll P18
JDM STI Twin Scroll
14411AA610VF41EJ207 2.0LJDM Forester STIJournal Bearing / Single Scroll P18
JDM Performance VF Series
14411AA650VF45EJ20 2.0LJDM WRX / Legacy EJ20 2004+Journal Bearing / Single Scroll P18
14411AA900VF60VariousSubaru Levorg / JDM applicationsJournal Bearing
Legacy / Forester / JDM
14411AA510VF45 / LegacyEJ255 2.5L2005-2007 Subaru Legacy GT (USDM) earlyJournal Bearing
Porsche Cayenne
VVQ1RHF5H VVQ14.5L V8 9482003-2007 Porsche Cayenne Turbo (Bank 1)IHI OEM Journal Bearing
VVQ2RHF5H VVQ24.5L V8 9482003-2007 Porsche Cayenne Turbo (Bank 2)IHI OEM Journal Bearing
VD430066RHF5H VVQ14.5L V8 9482003-2007 Porsche Cayenne TurboAlternate IHI Code
VD430067RHF5H VVQ24.5L V8 9482003-2007 Porsche Cayenne TurboAlternate IHI Code
GM Duramax LB7
8973077111RHF56.6L Duramax LB72001-2004 GM 2500HD / 3500 DuramaxIHI OEM / GM Part#
8971884545RHF56.6L Duramax LB72001-2004 GM 2500HD / 3500 DuramaxIHI OEM Alternate
Isuzu OEM
VIBFRHF54JB1TIsuzu Trooper / Rodeo 4JB1TIHI Model Code
VIBSRHF54JA1TIsuzu Rodeo 4JA1TIHI Model Code
VICFRHF5H4JX1TIsuzu Trooper 4JX1TIHI Model Code
VICIRHF5H4JX1TIsuzu Trooper 4JX1TIHI Model Code
Ferrari
VU12BRHB53LW (Left / LH)F120A 2.9L V81987-1992 Ferrari F40, Left TurboIHI Water-Cooled
VU13BRHB53LW (Right / RH)F120A 2.9L V81987-1992 Ferrari F40, Right TurboIHI Water-Cooled
VU21IHI VU21 (Left)F154CB 3.9L V8 Twin Turbo2015-2020 Ferrari 488 GTB / Spider / Pista, Left TurboIHI Ball Bearing Water-Cooled
VU22IHI VU22 (Right)F154CB 3.9L V8 Twin Turbo2015-2020 Ferrari 488 GTB / Spider / Pista, Right TurboIHI Ball Bearing Water-Cooled
VU21IHI VU21 (Left)F154CD 3.9L V8 Twin Turbo2019-2021 Ferrari F8 Tributo / Spider, Left TurboIHI Ball Bearing Water-Cooled
VU22IHI VU22 (Right)F154CD 3.9L V8 Twin Turbo2019-2021 Ferrari F8 Tributo / Spider, Right TurboIHI Ball Bearing Water-Cooled

No results for your number? Contact us at sales@theboostlab.com with the nameplate code from your turbo and we can identify it.

Common Failure Modes

Why IHI Turbos Fail

IHI turbos are well-engineered OEM units. Nearly every failure we see has an external root cause, the most predictable of which is the Subaru oil feed restriction. Understanding what caused the failure is the first step in every rebuild we do.

101

Subaru Banjo Bolt Oil Feed Restriction

The single most common root cause of VF series turbo failures. The oil feed line on EJ-series engines connects to the cylinder head via a banjo bolt. This bolt develops a restriction over time, reducing oil flow to the turbo bearing housing on startup when the turbo is spinning up from cold. Subaru issued a service bulletin specifically addressing this issue and recommends replacing the banjo bolt any time the turbo is replaced. If this bolt is not replaced at the same time as the turbo rebuild, the rebuilt unit faces the same oil restriction from day one. We flag this on every Subaru VF rebuild report.

202

Oil Coking from Extended Intervals

Subaru recommends 3,000-mile oil change intervals on turbocharged EJ engines. Extended intervals with conventional oil, or any interval with synthetic that has degraded under boost and heat, allow oil to break down inside the bearing housing. The degraded oil leaves carbon deposits that restrict passages and accelerate bearing wear on the next cold start. Turbocharged EJ and FA engines are punishing on oil. Short intervals with a quality full synthetic are the single best preventive measure after the banjo bolt replacement.

303

Journal Bearing Wear from Cold Boost

The USDM VF39, VF43, VF48, VF52, and VF54 are all journal bearing units. Journal bearings require a film of pressurized oil between the shaft and bearing surface. On a cold engine, oil is thick and slow to reach operating pressure. Boosting hard on a cold start, before oil has reached the turbo at full pressure, allows the shaft to contact the bearing surface directly, scoring both. This is accelerated by any restriction in the oil feed line. Let the engine warm up before demanding boost, every time.

404

Compressor Wheel Damage from Intake Tract Failure

Cracked intercooler pipes, loose clamps on aftermarket intake hardware, and broken boost leak test plugs left in the intake are frequent causes of compressor wheel damage on modified Subaru platforms. Debris ingested at compressor speeds causes blade tip erosion or bending. Even minor tip damage creates an imbalance that accelerates bearing failure at high RPM. Aftermarket cold air intakes and large intercooler kits with poorly fitting couplers are the main culprit. Every compressor wheel is inspected at teardown for ingestion damage.

505

Porsche Cayenne Heat Soak and Oil Coking

The Cayenne Turbo twin turbo setup packs two IHI RHF5H units into an extremely tight V8 engine bay running sustained high loads. The thermal environment is significantly more demanding than a typical passenger car turbo application. Hot shutdowns after spirited driving trap heat in the bearing housings with no active oil circulation. Over time this produces heavy oil coking in both CHRA units. Both turbos must be rebuilt together, since running a fresh unit alongside a worn one creates imbalanced boost conditions and shortens the life of the new unit.

606

Duramax LB7 Oil Contamination

The 2001-2004 Duramax LB7 is notorious for injector failures that allow diesel fuel to wash into the crankcase. Diluted engine oil loses its film strength and viscosity immediately, starving bearings throughout the engine including the IHI RHF5 turbo. An LB7 IHI rebuild without confirming the injector issue has been resolved will result in the same contamination damaging the rebuilt turbo. We flag this in every LB7 rebuild report. If the injectors have not been replaced or tested, that work needs to happen before the turbo goes back on.

Our Rebuild Process

Every IHI Done Right

We have been rebuilding IHI turbos since 2008. VF series parts are stocked in-house for the most common units. Every rebuild includes a complete teardown, root cause identification, bearing replacement, and in-house VSR balancing. Every Subaru VF rebuild report includes a call-out on the banjo bolt; we will not send a rebuilt turbo back without flagging it.

1

Teardown and Root Cause

Full disassembly and photography. Root cause identified before parts are ordered. On Subaru units we document oil passage condition and coking level and include banjo bolt replacement recommendation in every report.

2

Bearing Replacement

Journal bearings, thrust bearing, and thrust washer replaced. Ball bearing cartridge replaced on BB units (VF22, VF23, VF24, VF28, VF29, VF34, VF36, VF38). CHRA cleaned and oil passages inspected.

3

Wheel and Seal Inspection

Compressor and turbine wheels inspected for ingestion damage and erosion. All piston rings replaced. Seal plates and o-rings inspected and replaced as needed.

4

In-House VSR Balancing

Every rebuilt CHRA dynamically balanced in-house above OEM specification before final assembly. Not sent out.

5

Final Assembly and Inspection

Housings cleaned and inspected. Shaft play verified within tolerance. Turbo photographed and packaged for return shipment with rebuild report.

Common Questions

Frequently Asked Questions

What is the banjo bolt and why does it matter so much?
The banjo bolt is the hollow bolt that connects the turbo oil feed line to the cylinder head on EJ-series Subarus. It has a small internal passage that allows oil to flow through to the turbo. Over time, especially on engines that have seen extended oil change intervals or oil degradation, this passage narrows from varnish and debris buildup. The result is restricted oil flow to the turbo on every cold start. Subaru recognized this and published a service bulletin recommending banjo bolt replacement any time the turbo is replaced. It is one of the cheapest parts in the repair and one of the most important. Never reinstall a rebuilt turbo on an EJ engine without replacing the banjo bolt and both copper crush washers.
What is the difference between ball bearing and journal bearing VF turbos?
Ball bearing VF units (VF22, VF23, VF24, VF28, VF29, VF34, VF36, VF38) use a roller bearing assembly instead of floating oil-film journal bearings. The ball bearing design reduces friction at low shaft speeds, which means the turbo builds boost faster at lower RPM. This is why JDM applications with ball bearing VF units feel more responsive at part throttle than their USDM journal bearing counterparts. The tradeoff is that ball bearing cartridges are more expensive to replace and more sensitive to oil contamination. Both types are fully supported at Boost Lab.
Can I upgrade from a VF48 to a VF52 or larger?
In many cases yes, but the details matter. The VF48 (STI) and VF52 (WRX) use the same RHF55 frame and share mounting dimensions, so physical fitment is not the issue. The differences are in the compressor and turbine housing sizes and the boost controller calibration. Running a larger VF unit typically requires a tune to take advantage of the increased flow and to ensure boost targets are appropriate for the compressor map. Contact us before shipping and we can help identify whether the VF unit you want to run is the right fit for your engine and setup.
Do you work on the FA20DIT turbo from the 2015+ WRX?
Yes. The 2015-2021 WRX FA20DIT uses an IHI VF57 turbocharger (14411AA830). The FA20DIT is a direct-injection engine with a different oiling and cooling system than the EJ, but the IHI turbo itself follows the same rebuild process. Oil starvation on cold startup is still the primary concern, since the FA20DIT has its own set of maintenance requirements that affect turbo longevity. Contact us with your unit and we will confirm parts availability and turnaround.
How do I ship my IHI turbo?
Submit the rebuild form at repair.theboostlab.com first. Drain any residual oil from the inlet and outlet ports. Plug all ports to prevent contamination during transit. Double-box with foam or bubble wrap padding on all sides. Ship via UPS or FedEx to 37833 Pineapple Ave Unit A, Dade City, FL 33523. For Porsche Cayenne twin turbo sets, ship both units together in the same box when possible so we can cross-reference the pair at teardown. We will send a receiving confirmation.
Do you work with performance shops and dealers?
Yes. We work with Subaru performance shops, dealers, and multi-car fleets nationwide. If you are sending multiple IHI units regularly, contact us about wholesale pricing and shop accounts. VF48 and VF52 are our most common IHI units and we stock the components for fast turnaround on both.

Ready to Rebuild?

Start your rebuild request in our repair system. VF48 and VF52 parts stocked for fast turnaround. Every job documented from intake through return shipment.

Start Your Rebuild Request

37833 Pineapple Ave Unit A • Dade City, FL 33523 • sales@theboostlab.com