IHI Turbo info

[Guest Raynes]

This was on the previous forum stickied and was damn useful. Not my work, but I did tidy it up, add a few bits that should be there from other sites, and some common knowledge that has been floating around.

IHI turbo.

The VF series (VF22, VF23, VF24, VF29, VF30) are the most common bolt-on replacement turbos for the straight inlet MHI TD04 Turbos found on some WRXs and Foresters. The differences are in their wheels and housings to achieve different flows. Version 1-2 WRX and STIs and early Legacys will require modification to fit these, as they use a 90 degree bend on their factory turbo inlets. Later model STI turbos (Version 8+) switched to a twin scroll design, which utilize a different sump, exhuast manifold and up-pipe than earlier models.

The VF22 has the largest potential for peak horsepower. In other words, in the IHI model range, the VF 22 supports the highes boost levels. It is capable of running up to 25 psi. Because it is a roller bearing turbo, turbo lag is minimal...the boost comes on around 3300 rpm. Expect to max out the VF22 somewhere in the 400-450 hp range.

The VF23 starts the middle ground. It comes on boost around 3100 rpm and is capable of running 20 psi of boost. Expect to max out the VF23 somewhere in the 300-350 hp range.

The VF 24 starts to come on around 2900 rpm and will significantly improve power through the midrange over the stock TD04 turbo. However, the VF 24 is only capable of running around 17 psi.

The VF23 and VF 24 are a great replacement for those who value drivability higher than maximum power.

The VF29 & VF30 delivers a very wide increase in torque over the standard TD-series turbos. It is important to note that the VF30 is not a roller bearing turbo.

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VF13

Primary turbocharger used on the JDM Legacy MY93-95.

VF14

Secondary turbocharger used on the JDM Legacy MY93-95.

VF18

Primary turbocharger used on the JDM Legacy MY96.

VF19

Secondary turbocharger used on the JDM Legacy MY96.

VF20

Turbocharger used on the JDM Legacy MY97.

VF22 (460cfm at 18.0psi, 250-325whp, Bolt-On) Used on the V3 Subaru Impreza WRX

This turbo has the highest output potential of all of the IHI VF series turbos and is the best choice for those who are looking for loads of top end power. The top end power however, does not come without a cost. The VF22 spools significantly slower than the rest of the IHI models due to the larger P20 exhaust housing and is much less suited for daily driving than some of the other models. Although the largest VF series turbo, the VF22 is not quite optimal for stroked engines or those who wish to run more than 20PSI of boost. Expect to achieve full boost with the proper mods and a quality tune between 3200-3700rpms.

VF23 (460cfm at 18.0psi, 250-325whp, Bolt-On) Used on the JDM V3 Subaru Impreza WRX.

This turbo is considered a great all-around turbo. Like the VF22 it utilizes the largest P20 exhaust housing. This housing is mated with a smaller compressor housing of the of the VF24. This turbo is considered optimal in applications with range from mild to slightly wild. It does not have the same top end power of the VF22, but spools up significantly quicker. Expect to achieve full boost with the proper mods and a quality tune between 2800-3300rpms.

VF24 (425cfm at 18psi, 250-325whp, Bolt-On) Used on the V4 Subaru Impreza WRX STi.

This turbo shares its compressor housing with the VF23 however, this housing is mated with a smaller (P18) exhaust side. The smaller characteristics of this turbo allow it to provide ample bottom end power and quick spool. This turbo is very popular for Imprezas with automatic transmissions and Group N rally cars. Expect to achieve full boost with the proper mods and a quality tune between 2800-3300rpms.

VF25

Primary turbocharger used on the JDM Legacy B4. Utilizes a thrust-bearing design and a P12 exhaust housing.

VF26

This is the standard equipment primary turbocharger used on the JDM Legacy B4. Utilizes a divided thrust-bearing design and a P14 exhaust housing.

VF27

This is the standard equipment secondary turbocharger used on the JDM Legacy. Utilizes a ball-bearing design and a P18 exhaust housing.

VF28 (425cfm at 18psi, 250-325whp, Bolt-On)

This turbo came standard on the STi Version 5. In terms of overall size, it is smaller than the VF22, VF30 and VF34, and about same size as the VF23.

VF29 (425cfm at 18psi, 250-325whp, Bolt-On)

This Turbo is nearly identical to the VF24, with the same compressor and exhaust housings. However the compressor wheel in the VF29 is has been changed slightly. The changes made to the compressor wheel in this model are generally viewed as improvements, and as such this unit is typically chosen over the VF24. Has a different location for the pressure hose on the wastegate actuator.

VF30 (460cfm at 18psi, 250-325whp, Bolt-On)

The VF30 is commonly considered the best bang for the buck turbo in the IHI VF series line. A relatively new model the VF30 features the same exhaust housing as the VF24 but a larger compressor side similar to the VF22. The combination of these two parts results in increased output potential without the lag associated with the VF22. Although it doesn't offer the top end supremacy of the VF22, the VF30 is a great compromise between these unit and the quicker spooling models. Found on JDM Version 7 STI.

VF31

Utilizes a P11 exhaust housing.

VF32

The secondary turbocharger used in the B4 IHI VF32. On the exhaust side it uses a 46.5/35.4mm 9-blade turbine wheel, teamed with a 52.5/36.6mm 10-blade compressor wheel. It's rated at 180,000 rpm. Both the primary and secondary turbochargers use a floating metal centre bearing - not ball bearings.

VF33

The primary turbocharger used in the B4 is an IHI VF33 unit, which uses a 46.5/35.4mm 9-blade turbine wheel and a 47.0mm/35.4mm 6 + 6 blade compressor. At idle, the turbo spins at around 20,000 rpm and it can go on to a maximum speed of 190,000 rpm. It has a 17mm diameter wastegate opening to bypass excess exhaust gas. It utilizes a P11 exhaust housing and a divided thrust-bearing design.

VF34 (460cfm at 18psi, 250-325whp, Bolt-On) This is the standard equipment turbocharger used on the JDM V7 Subaru Impreza WRX STi Spec-C.

The VF34 is nearly identical to the VF30, with the same exhaust housing and compressor. However the VF34 goes back to the ball bearing design, and in doing so achieves full boost approximately 500RPM sooner than the comparable VF30. The VF34 is the most recent IHI design and as such costs slightly more than its counterpart. Top end performance and maximum output are identical to the 30.

VF35 (425cfm, 250-325whp, Bolt-On)

The VF35 has identical internals as the VF30 and it uses divided thrust bearings. However, the exhaust housing is a P15 which means this turbo will have fantastic spool characteristics. This turbo is standard on the new WRX Type RA. LIMITED SUPPLY.The VF35 is similar to the VF34. It utilizes the same compressor housing and the same compressor inducer size. The differences are in the divided thrust-bearing design and the P15 exhaust housing. This allows the VF35 to spool slightly quicker than the VF34 at the cost of less top-end performance.

VF36 (430 cfm, 250-325whp, Modification Required) This is the standard equipment turbocharger used on the JDM V8-V9 Subaru Impreza WRX STI Spec-C Type RA.

Roller bearing version of the twin scroll VF37, also has a titanium turbine and shaft for even quicker spool. Same compressor housing as VF30/34, however twin scroll P25 exhaust housing provides slightly better top end output due to reduced exhaust pulse interference. This turbo is good for 400HP and used on JDM STI Spec C from 2003 onwards.

VF37 (thrust bearing) (430 cfm, 250-325whp, Modification Required)

Enter the age of twin scroll IHI turbos. Same compressor housing as VF30/34, however has a new twin scroll P25 exhaust housing that provides slightly better top end output due to reduced exhaust pulse interference. Twin scroll also provides better spool up for improved low down response over the VF30/34. This turbo is good for 400HP and used on JDM STI from 2003 onwards.

VF38

Twin scroll turbo with titanium turbine and shaft. Smaller compressor housing than VF36/VF37 provides tremendous spool up capabilities but less top end than VF36/37. The spool capabilities of this turbo are demonstrated on the JDM Legacy GT, which reaches peak torque at 2400RPM.

VF39

(250-325whp)

Single scroll turbo used on USDM STI and latest 2.5L STIs released internationally. Smaller than VF30/VF34. It can be found on all model years from 2004-2006. The VF39 utilizes a thrust bearing design and the P15 exhaust housing.

Expect to achieve full boost with the proper mods and a quality tune between 3000-3500rpms. 2002-2005 WRX owners will need fuel upgrades for this turbocharger and proper engine management is highly recommended for all vehicles that utilize this turbo aftermarket. Though they are prone to cracking (wastegate hole), VF39’s can be had for very cheap if bought used. Not because they're an inferior turbo, but the exhaust housing can be cracked near the wastegate.

VF40

Used on the USDM Subaru Legacy GT. It can be found on all the current model years from 2005-2007.

VF41

Used on the JDM Subaru Forester STI. It utilizes a P18 exhaust housing.

VF42

Exclusive turbo to the S203/S204 models, this features a twin scroll design with a slightly larger compressor than the VF36/37 turbos and different turbine design (more blades). The VF42 is a roller-bearing turbo and is likely of similar size to the VF22 turbo, but with twin scroll exhaust housing for faster spool and superior top end performance due to reduced exhaust pulse interference.

VF43

(250-325whp, Bolt-On)

Used on the MY07 USDM Subaru Impreza WRX STI. It can be found on both base STI's and STI Limited's. The VF43 utilizes a thrust bearing design and the P15 exhaust housing. The difference between the VF43 and the VF39 used previously on STI's is the size of the wastegate. The VF43 has a larger wastegate designed to reduce boost creep issues.

[Joker]

hah you bloodly left out all the TWIN turbo LEGACY VF's!

turboist

Similar text here : http://www.ozliberty.com/forums/showthread.php?t=1286

[Guest Raynes]

Hah lol oops ;D. I left a bit out actually. Fixed

[GC8E2DD]

www.mrtrally.com.au/performance/docs/turbo-data.pdf

[G-unit]

still nothing for the vf8 and 10 turbos

[BC5RA]

Hard to get concrete info on those Turbo's Gunit, but heres some figures for you.

A TD04 will flow 360cfm, a VF10 may flow slightly higher than that and a VF8 even more.

A VF8 or VF12 (AUSDM) flows very similar to a VF28 (without the RBB spool) so put them somewhere between 380cfm and 420cfm.

[Guest]

anyone got anything on a vf10 anything??

[Bazza-NZ]

Anyone know how the VF8/10 are meant to be plumbed in?

I know the top one is oil feed from engine

2 side ones are water

(Assuming) the bottom one is for oil exit?

where should the bottom one be attached to? my project seems to be missing the bottom bit ???

[sickmatesick]

pretty sure it has a hose that joins onto a pipe right below it. its a real pain to get on.

[leggyfreak]

so what turbo would be better out of a vf 24 and a vf8

[EJ20T]

I wouldnt be strapping a VF10/8 to anything 2.0L these days when theres so many better options. VF10's run out of puff at like 5.5k on a old EJ20G

[funkytown]

 leggyfreak said:

so what turbo would be better out of a vf 24 and a vf8

lol totally the vf24... the 8's are just real old

[Pappu1]

 funkytown']

[quote name='leggyfreak said:

so what turbo would be better out of a vf 24 and a vf8

/quote]

lol totally the vf24... the 8's are just real old

plus the 24 has more hp potential and similar type spool...

if u can get a 28 for the same money i wud recomend that