VF52 fueling?

[BAC5.2]

those are my thoughts too.. Really i'm kinda stuck between an

FP Green (seems to have everything i want but i heard they break more frequently than the others)

Dom 2.5xtr ( seems to make the same power but with more lag)

20g (seems to be a little less powerful but the same spool as the FP green)

for my next turbo.

 

Honestly i should be building up the VF52 since i'm getting ready to sell one lol.

 

Get the Green. Best turbo for that "class", IMO.

 

The VF52 can use the stock oil line, right?

[CTATV]

 

 

Will I need a new timing belt?

 

if your over 105k miles, yes.

[BAC5.2]

I just rolled 40k. Maybe I should change it early...

[iNVAR]

sure you can de-tune so to speak and run it with stock stuff but then why upgrade the turbo?

I'd only be doing it when my VF40 meets its inevitable demise at some point. I'm at 65K miles currently.

[CTATV]

I'd only be doing it when my VF40 meets its inevitable demise at some point. I'm at 65K miles currently.

 

my 40 popped at 63k miles

[BAC5.2]

I've heard loads of different borked '40 mileages. That one person just posted about an 05 OBXT that pooped at 44k.

[iNVAR]

You guys are scaring me...

[BAC5.2]

You guys are scaring me...

 

http://legacygt.com/forums/showpost.php?p=3378155&postcount=49

[CTATV]

I was running COBB stage I 93 octane off the shelf map when mine went, pretty much stock...

[BAC5.2]

I was running COBB stage I 93 octane off the shelf map when mine went, pretty much stock...

 

I wonder if the tune really had anything to do with it...

[CTATV]

I wonder if the tune really had anything to do with it...

 

i doubt it

[BAC5.2]

Bingo.

 

But that reminds me to check the banjo bolts at my next OCI.

[fahr_side]

A few VF-52s have failed, mostly stg1 or stg2. Remember the turbo has to spin faster to make more boost...

 

I just got the STi pump. The buckets are the same so it will drop straight in.

 

I wouldn't buy an FP turbo. They can't even design an oil line that fits.

[BAC5.2]

I've had good luck with their turbos, but I've never actually owned one. I HAVE broken a Green at 139mph once. But that was an external issue caused by something else. The shaft snapped. Whoops. Talk about scary.

 

So are they failing because the wheels are hitting the housings? Or are they failing because of something else? The 52 isn't BB, is it?

[underpowerd]

vf52 not bb afaik. i agree with fahr that the ihi bb units tend to hold up better.

[BAC5.2]

Which IHI turbos are BB? Obviously none that are a drop-in for the '40.

 

The BNR 16G is built on the '40, right? So that's prone to the same problems as the '40, right?

[underpowerd]

bb: vf22, vf23, vf34, vf42ts, vf36ts, maybe some others. these mentioned are all sti-type outlet.

[fahr_side]

Which IHI turbos are BB? Obviously none that are a drop-in for the '40.

 

The BNR 16G is built on the '40, right? So that's prone to the same problems as the '40, right?

Beyond the JDM twinscroll stuff I don't remember too many. VF-34 is BB IIRC. But no, there is no drop-in IHI BB turbo in VF-40 fitment. It might be possible to build a hybrid with a VF-40 compressor cover though.

 

Bryan's turbo is VF-40 housings and complete MHI CHRA. You get the 8cm2 exhaust housing that most TD05s don't, and use the stock compressor cover that fits the prized stock intercooler. Of course it's the stock housings that make all the power, and of course this helps to keep the weight difference down to a few grams. I think taping a small coin to the underside of the heatshield would prevent any horrible unbalance that might hold you back at the track or cause some terrible accident.

 

Want to know my ultimate performance secret? I have a second stock intercooler just laying loose in my trunk and it adds so much performance. It even moves from left to right in corners like a trunk monkey does. More power AND better handling.

[fahr_side]

bb: vf22, vf34, vf42ts, vf36ts, maybe some others. these mentioned are all sti-type outlet.

VF-22 is not BB, but it is about the biggest turbo in the RHB55 series.

[underpowerd]

^ it certainly is; i have a chra in my basement

 

oh, add vf23 to the list (edited).

[BAC5.2]

Excellent info. Perhaps I'll look into the 16G a little more, if it's going to improve reliability over the IHI options.

 

I'll have a spare stock intercooler after I put my worse performing one on. Maybe I'll plumb it into the exhaust to help cool it down before exiting the car. That should cause something of a net-thrust effect, and I'll gain a few extra MPH.

[underpowerd]

old rundown:

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 large 40 mm compressor wheel. it 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. Utilizes a standard ballbearing center design. Recommended for use on cars with significant modifications and where flow capacity is more important then response time. Expect flows around 490 CFM at 18.0 PSI

 

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 for fast response and excellent low and mid-range performance. It does not have the same top end power of the VF22, but spools up significantly quicker. Standard ball bearing center section. Excellent bolt-on replacement for the standard WRX turbo on cars without any other major modifications. Expect flows around 430 CFM at 18 PSI.

 

 

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. Not recommended for stroker engines or engines with high boost as turbo is small and can over speed. Best turbo for cars that want the best bottom end and least lag. Expect flows around 425 CFM at 18 PSI

 

 

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. Expect flows around 425 CFM at 18 PSI

 

 

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. Has a different location for the pressure hose on the waste gate actuator Expect flows around 425 CFM at 18 PSI

 

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. This is the ideal turbo for the average customer looking for fast excellent mid-range performance and response. This is not a ball bearing turbo as it utilizes a sleeve type design. Expect flows around 460 CFM at 18.0 PSI

 

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. Expect flows around 460 CFM at 18.0 PSI

 

VF35

The VF35 utilizes the same compressor housing as the VF34 however it also features a divided thrust or offset ball bearing design. The smaller P15 exhaust housing for quicker spool up and a slightly more limited top end. The compressor inducer size is the same as a VF30/or 34 turbocharger. This turbo is standard on the new WRX Type RA.

 

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.

 

See Subaru New Zealand - Technical Tips

 

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.

[fahr_side]

Excellent info. Perhaps I'll look into the 16G a little more, if it's going to improve reliability over the IHI options.

If it's a price difference in several hundreds of dollars... get the VF-52. If it's close, step up to the MHI guts. Bryan's build quality and service are great.

 

I'll have a spare stock intercooler after I put my worse performing one on. Maybe I'll plumb it into the exhaust to help cool it down before exiting the car. That should cause something of a net-thrust effect, and I'll gain a few extra MPH.

You know, you remind me of those very high altitude UAVs that recycle their exhaust gas back into the intake after a heat-exchanger. The incredible efficiency of that plastic intercooler might even allow you to run a completely closed-loop system and thus save us all from global warming. God bless Subaru for creating this amazing piece of engineering!

 

Oh no. Something wrong with my logic here. There is scientific evidence that proves global warming is happening, which means I must be wrong. Damn!

 

Well anyway, I am going to start buying up all those plastic intercoolers people so foolishly throw away before everyone realizes how valuable they are or Subaru stops making them.

 

Thanks underpowrd for the IHI reminder. I probably pay them less attention than they deserve, mostly because of lack of compressor maps or spare parts.

[rao]

This whole turbo thing seems a little sketchy to me.

[fahr_side]

This whole turbo thing seems a little sketchy to me.

Actually, I think if you had enough stock intercoolers you wouldn't even need a turbo. But, then it would be very hard to get your weight distribution right if you ditched it, since the densities are so different.