VF34 and VF39 are the same turbo but the 34 has a larger wastegate port and ball bearing section. The same P18 exhaust housing is less prone to cracking on the 34 for some reason. Spool is about 500rpm sooner depending on tune and top end power is equal to, if not, slightly higher than the VF39. Both share the same RHF55 compressor housing. If you have already have a VF 39 on your WRX, save your money for an 18G as a next improvement over the VF39. All you're paying for is spool, which has nothing to do with overall power. But going from a TD04 to a 34 is a night and day difference. A very awesome turbo. Good luck tp the seller.

 

True dat! It's a big difference from stock! Damn Daniel surprised u didn't jump on this!

 

Money has been sent!

 

actually the VF30 (JDM STI) and VF39 (USDM STI) have the same rear P18 housing where as the VF34 (JDM STI Spec C - pre-twinscroll) does not. The VF34 rear housing is slightly larger. The VF34 has a ball bearing cartridge. Both VF30 & VF39 are prone to cracking. The VF34 flows more air than the VF39. On a 2.5L engine both turbos are ok but you'll wants something bigger soon. on a 2.0L both turbos are great upgrades from the stock TD04 turbo.

 

^thanks for the info.

 

FML. first lorenzos 34, now this ones sold. maybe it wasn't meant to be? lol

 

a 39 wouldn't be a bad option.

 

Really? I saw P18 stamped inside the turbine inlet of the VF34 before installing it because I too thought it had the bigger P20 housing of the VF22.

If you look here, both the VF34 (left) and the VF28 (right) have P18 exhaust housings, similar to the VF30 and 39.




Dane, where is the VF-dirty ***** going in?

 

I want to get rid of mine too for a Garrett T3 Super 60-trim, lol. The VF34 seems a liiiiiiittle on the big side for my tiny 1.8L.

 

You willing to sell? PM me with more information.

 

Hmm... I know for sure the VF39 and VF30 have the same P18 housing. I'll pull it out of the shed in a little while and take a picture of it.

you could be right regarding the P20 housing on the VF34. I know people are making hybrids with the VF34 fitting a P20 housing. If they do use the P18 housing (which could be the case) it is a little funny why the VF34 isn't prone to cracking like the VF30 and VF39.

EDIT: This is some old information I found on the net regarding the different VF turbos we've been discussing. WE both are wrong joejoe

 

I also dug this old comparison from various forums:

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.

btw, I made a typo on my last post and fixed it. The turbo next to the VF34 is actually a VF28, not VF23. VF28 has the P18 exhaust housing, VF23's have P20 exhausts.

 

The VF dirty ***** is going on the Bugeye for just long enough to allow me to finish the short-block for it. I plan on moving up to a larger GT series soon after. Right now I'm working on adjusting a XPT stg2.5 vf-39 map to run this turbo. I have to adjust for the better spool characteristics and my larger 850cc injectors. Should turn out to be a good daily driver to hold me over.