mystery inc.

hi ppl. i was looking in changing my turbo. i currently have the vf28. now i have heard rumours that the vf22 is the bigger one. they say it gives big boost all the way to 7000 rpm. would this be a good swap for power gains. i know this one doesnt hit full boost till 3300 rpm. or is there any other turbo to consider with better spool up times. i want to keep the power figures about 350+ bhp. but could do with extra torque.

paul g

P1 FEK

iTrader: (1)

Just copied Floyds post on 22b.com, hope you don't mind mate.Great amount of imfo.

IHI Turbos


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

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.

mystery inc.

my car is currently running 1.45 bar of boost. so this means that the vf22 cant cope with more than 20 psi so in fact it would be no good for my car and boost setup. the vf34 is better spool up but with less power at top end. what about the tdo5 18g would this be any good? or would anyone recomend me sticking with either one of the vf range.

P1 FEK

iTrader: (1)

surely though after fitting a vf22 you would need a remap and because it's a larger turbo you would'nt need to run at the same high boost pressure in order to flow more air and therefore produce more power?

scoobyDAZZA

you don't say what version scoob you have
if you have a uk classic then a new gearbox won't be far around the corner with 350 bhp
my vf34 on my uk classic my00 is running 348 BHP with supporting mods.
a td05/18g would probably give upto 370 but remember the clutch/box etc etc
and you WOULD need a remap whatever turbo you get.........

mystery inc.

the car i have is a type-r limited edition. 1999. i think i will probably go for the same turbo thats on it then. which i think is the vf28.

scoobysmiff

iTrader: (2)

if you want better torque try a set of ported headers from Harvey and one of his option 2 up-pipes, if you port the turbo as well to match the up-pipe, with a remap to suit you should notice a respectable improvement

StickyMicky

i would look for a p20 exhaust housing and convert yours to a vf23, if your turbo has plenty of life left

vf22 tend to snap blades a bit to easy for my liking

banny sti

iTrader: (68)

Hi mate i have a VF23 for sale, if you are interested pm me

Banny