22 replies to this topic

[Scuba-Roo]

Been trying to find some info about Subaru single turbo's so i can make up my mind as what i want to get when i buy one.

Found this but please feel free to add thoughts and more info

VF22
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.

VF23
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.

VF24
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.

VF28
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
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.

VF30
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.

VF34
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
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.

VF36
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)
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
Single scroll turbo used on USDM STI and latest 2.5L STIs released internationally. Smaller than VF30/VF34.

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.

PE 1818 The 1818 supposedly comes on boost extremely fast...which make it great for road racing or aggressive driving (remember to be responsible :^). The 1818 maxes out somewhere between 350-375 hp.

PE 1820 The 1820 is larger than the 1818 and is capable of running more boost, but at the expense of more turbo lag. Expect it not attain full boost until you have passed 4000 rpm. However, it can be tuned to 400+ hp.



IHI & Garret Turbo Specs
Model Type Compressor Inlet Diameter Compressor Housing Nominal Turbine Housing Turbine Approx A/R Compressor Wheel Blades Turbine Wheel Blades Waste Gate Actuator Turbine Casting ID & Batch
VF22 Roller Bearing 48.5 A 9.4 PZ20-H 94001 0.71 5 11 C395 H, H4
VF 23 Roller Bearing 46.7 B 9.4 PZ20-H 94001 0.71 6 11 C395 8psi TBA
VF 24 Roller Bearing 46.7 B 9.4 PZ18-H 94001 0.63 6 11 C418 8psi H, S4, 66
VF 30 Bronze Bearing 47.9 C 9.4 PZ18-H 94001 0.63 6 11 C484 H, S4, IC F55
VF 34 Roller Bearing

From this forum


My set-up will be a legacy GT engine, fmic/twist mount turbo set-up, STI-RA ecu, 440 injectors, 90mm AFM in gaurd pod, custom dump to 3" exhuast. Power wise, i'd be happy with 160-170kw@w, not that i'll be chasing numbers, just going off car's i've been in with them dyno figures. I think for what i want a VF23 will be good, but i'd like to look around more, alot of people seem to run the TD05's though.

Any contribution will be muchly appreciated

Mark

[Richo]

td05-16g will be half the price of any of the VF's. will see 160 with ease. My car had a 16g and made 152kw running rich as Josh

[Shaz]

Is the VF23 what came on the V3 STis?

I'm pretty sure that's what's on my car.

Cheers,
Shazza

[alexGT]

td05-16g will be half the price of any of the VF's. will see 160 with ease. My car had a 16g and made 152kw running rich as Josh

and you can buy them brand new, not risking on a second hand turbo.

kando dynamics pretty much all TD series turbos (non t/s) are around the $700-800 mark

[Scuba-Roo]

Thanks richo, price is a pretty major factor in my choice.


Shaz according to google yes, aswell as the 22b.


Alexxx, did an eBay and found some for $300-$400ish if i remember, with warranty, probably not the same quality though.

I did also read people getting good results with a VF35.


Atleast theirs different choices

[Alex]

VF34 is probably the best for your application, Mark.

IF you get bored with that... (HA!!!) upgrade the rear housing to a P20, and you'll have an absolute sledgehammer.

Trade off is, that you'll have more lag.


But for a track hack.... why not?

[alexGT]

Thanks richo, price is a pretty major factor in my choice.


Shaz according to google yes, aswell as the 22b.


Alexxx, did an eBay and found some for $300-$400ish if i remember, with warranty, probably not the same quality though.

I did also read people getting good results with a VF35.


Atleast theirs different choices

i had a vf35 on my old wagon, great turbo. so much early boost! wound up to 7000rpm no worries either!

i wouldn't touch the cheapo TD's. Kando uses genuine MHI parts, no idea what the others use

[Scuba-Roo]

From what I've seen the VF 34's a bit to much money for what I'd like to spend. Especially as I'm not after a great deal of power. While the car is a track hack it'll still get driven around on the road a bit. So I don't want anything with too much lag. But thanks Alex

Ah okay cool Alexxx, I did see some good results on rexnet with them.

[Alex]

How much are you looking to chuck towards a tarbo, Mark?

[Scuba-Roo]

Was looking around the $300-$500 mark, obviously i want to pay as little as possible for best perfomance

[Alex]

that's easy VF moneiz.


VF23 or VF24

[Scuba-Roo]

Something like this
http://www.importmon...4.jpg&title=GC8 WRX STi3 VF23 9611

a VF35 i found on rexnet also fits into that budget

[Alex]

that 23 looks good.

[Scuba-Roo]

It's on my watch list so just have to wait and see how it pans out

[fatcat67]

That is dead cheap. Just over $200 landed by air.

[Scuba-Roo]

That is dead cheap. Just over $200 landed by air.

yeah i know! im not the highest bidder though so i'll wait and see how the auction goes


like $170 is you go buy sea

[XXB4XX]

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.

- I can vouch for this, man, the pin pack you get from only half throttle is unbelievable, WOT is pointless in the GT off the line

[Alex]

Twin scroll makes baby Jesus cry for an early Subaru.

You need to change way too much: Sump, headers, up pipe, dump pipe, and most importantly ECU tune.




Just for a turbo (and one that's notorious for failure)?

No doubt, there are other twin scrollers out there that yield great results... but for an Early Subaru, you just need to have all the above ready for it, for minimal gain versus the economic outlay.

And that gain, as reported by Al by one of his twin scroll conversions, was linearity, not so much power gain.

[Scuba-Roo]

as reported by Al by one of his twin scroll conversions, was linearity, not so much power gain.

Heard pretty much the same thing from MSR

[alexGT]

T/S not so good for early models. AVCS helps a buttload in that respect but really not worth the effort for an early model track car. you just want a straight bolt in job.