VF30 vs FV52

[RecklessWOT]

Curious if anyone has any experience with both turbos (or at least enough detailed knowledge). 

I am building a new engine for my '05 as I finally bent a valve AND wore a piston skirt damn near clean off (looks to have been running too hot on driver's side head) with ~205k miles on it, been running it hard for a long time stage2+, so I knew it was coming sooner or later.  I am over-building the block and heads so that one day I can go stupid with the power even though I'm only currently looking to get into the 320-350whp range (can't afford to build up my 5spd yet and have no desire for a 6spd), if I'm already in there might as well just do it once and get it over with now.  I had initially planned on going with the VF52, but my close friend who owns a Subaru shop is able to sell me a low mileage JDM VF30 and all necessary mods to make it work for substantially less than just buying the VF52 itself.

 

From what I understand the two turbos appear to have similar flow and power capabilities.  Is there any major downside to the VF30 vs the VF52 besides all of the mods required (like I said I'll already have all of that so it's a non-issue)?  I know at that point it won't really be a "true Legacy engine" as it will basically just be an STI, while I can be a bit of a purist at times I can totally live with that.  I will still save all of my legacy stuff so I can go back and switch setups later on if I want.  I know the VF52 is very popular but I'm not having much luck finding a ton of info about the VF30.  Any big shortcomings, anything specific to be weary of?

 

Thanks in advance for any info, anything you have to add is appreciated.

Edited October 29, 2022 by RecklessWOT

[Infosecdad]

Probably because the VF30 is from the mid-90's WRX.

It has a different outlet, so you would need to get adaptors/different hoses if you are running a TMIC.

JMPs VF52 will likely perform better, but I understand the price pressures.

If you have a tuner in mind, maybe ask them if they are good with trying to tune a VF30 setup as well.

[JoeInOregon]

You are going to find tuners with more experience on the vf52, plus replacement turbos and associated parts will be much easier to find .

 

A jmp vf52 will likely set you back about 8 or , possibly a bit more , or less a brand new one someone horded and never used  sold on here for like 7 something last month  .

 

If I was going to do something jdm and difficult for no reason I would do a twin scroll

[RecklessWOT]

Yeah I'm aware that it's JDM and weird.  But it's coming off a complete JDM engine that my friend imported basically just to put the shortblock and heads in his '05 WRX but has changed everything else, so like I said we should have ALL the necessary parts to make it work laying around (the turbo itself obviously, piping, sti TMIC, manifold, fuel rails and pink injectors, straight through "TGVs" as opposed to my gutted stock legacy TGVs, etc, etc.), and I more or less have free reign of a massive machine shop at work so any little custom thing I might need I can probably fab up otherwise. 

I don't want to spend the money on the VF52 since this isn't my final build, I intend to go much further once I have the funds to build my transmission stronger, this will just be fun for a year or two.  If the VF30 will make the same power for less money, then I'm a fan.  I know it's unusual, but since I'm not gonna keep this setup forever I can't justify spending more money than I have to.

As far as tuning, my friend is going to custom tune it with(/for) me when I'm done building it, so I'm not too worried there.  I trust his work, he's always built good stuff in the past, and computers/electronics is the one place we differ.  I can build up an old school pre-OBD V8 or straight 6 and make a beast and I'm the only capable bodywork guy between us, but when it comes to electronics and tuning I'm not gonna pretend I know what I'm doing.  But he's always been great and I'm confident he's not gonna sell me a setup he can't tune.

 

I just didn't know if anyone has anything bad to say about the turbo itself.  Are there any design flaws or shortcomings?  Am I actually incorrect to think it will have similar flow /outout potential as the VF52?

Edited October 29, 2022 by RecklessWOT

[Rusty9]

another nugget to consider is the VF30 was designed for the 2.0 liter and most likely won't perform the same on a 2.5

people sell very low mileage vf52's on nasioc for a few hundred all the time.

[RecklessWOT]

Are the flow rates and power outputs similar? 

From what little mention I can find about the VF30 it appears that it does have a similar flow rate and power output potential to the VF52, but I haven't seen any specific data/numbers.  Is that an incorrect assumption?  Anyone have proof one way or the other?

 I appreciate the input you guys, but I have a VF30 basically laying around that I can have for next to nothing.  I am not interested in how cheap a used VF52 can be had for on a different website, I do not have a twin scroll at my disposal, I am not worried about modifications required to make it work, etc, etc.  I understand the VF30 was designed for a 2.0, honestly I don't care if it was designed for a diesel truck I was just asking if anyone actually has data or numbers or facts that I need to consider about the turbo itself.

Does anyone actually have real life experience with the VF30?

Is it prone to bearing failure and exploding, etc?  I know the VF52 is a popular turbo and I was looking at one for a while myself, but now I am merely trying to look for actual info on how it stacks up against the VF30.  It seems like everyone here really likes the VF52 and I understand that, I was gonna get one myself.  But I'm now just trying to compare the two turbos.  Does anyone have any info on how similar/dissimilar they actually are performance wise?

Not trying to come across as a jerk, but telling me "oh VF52s aren't that expensive" doesn't answer my question.  Now out of pure curiosity I just want to find the answer to my original question.  At this point, I'd almost turn down a free VF52 just to be that weird guy with a VF30 unless the VF30 really is a bad turbo.  If you don't have any useful info about how the two turbos compare, please save the "oh but the VF52 is better because I like it" stuff.  I am looking for real firsthand info, or a link to flow charts, etc.  Please nobody get mad, I'm not trying to hurt anyone's feelings, I just am looking for an answer.  I really appreciate the thread bumps, but it isn't getting me closer to the info I am looking for

Edited November 1, 2022 by RecklessWOT

[kzr750r1]

Most of the people who may have experimented or have experience with alternative turbos are no longer active here.

Many who remain are just trying to keep their cars rolling going back to mostly stock configurations.

May want to ask over at https://forums.nasioc.com/forums/ 

[Infosecdad]

I know what you are looking for, but most of the people that ran VF-30s are no longer around.

Assuming you have searched and found the specs and stories on nasioc, rs25.com, wrxtuners.com, www.scoobynet.com, www.i-club.com, subaruidiots.com, and so on.

Everything I've read would lead me to believe that it's fairly comparable with a VF-52, but probably a little below it.

Read warnings about most of the reported performance numbers on 2.0L, and the 2.5L numbers will be lower.

Reading stories, seems like it's a decent turbo, better than the old TD series, one of the better, older VFs (it's a 30yo design).

My guess is that it's between a VF-40 and a VF-52 with other things being equal; I wouldn't expect it to be able to break 300 WHP, but that's just my opinion.

Will you regret taking the deal and running it? If it's in good shape, it shouldn't grenade your engine.

[Max Capacity]

Just saying, have you googled your question ? You can get lots of info on flow of the turbos if you know how to understand what your looking at.

I asked google for pictures of a vf30, they have a different tmic flange. Will you need to buy something different to adapt to your tmic ? 

FWIW, those of us with a vf52, love them on these cars. With all the money you already spent, why not spend a little more and get what we/everyone knows works well...?

[RecklessWOT]

3 hours ago, Max Capacity said:

Just saying, have you googled your question ? You can get lots of info on flow of the turbos if you know how to understand what your looking at.

I asked google for pictures of a vf30, they have a different tmic flange. Will you need to buy something different to adapt to your tmic ? 

FWIW, those of us with a vf52, love them on these cars. With all the money you already spent, why not spend a little more and get what we/everyone knows works well...?

I've never been able to get google to work well for me TBH, of course I tried there first but I'm pretty bad with computery type stuff, I have been unable to find much specific to answer my question (that's why I'm asking for others input in the first place lol). 

They do in fact have different TMIC flanges, but as mentioned above (it was a long winded post, I don't blame anyone for glossing over it.  Seems being descriptive on the internet these days is frowned upon) I have literally everything needed to make it work (my buddy bought an entire JDM take out engine just for the shortblock and heads so anything else I need is up for grabs) and can buy the WHOLE setup for less than just a VF52.  It's more than just the intercooler, we're talking intake manifold, fuel rails with STI pink injectors, straight through JDM TGVs instead of my gutted stock ones, the VF30, a set of Tomei headers and uppipe, etc etc.  That's all cheaper than just a VF52.

I understand what you're saying about why not spend a little more and buy what works well, but this is not my final build merely a stop off point till I can afford to throw few grand at my 5spd and associated parts to make it handle like 450whp.  The car will be a monster one day, I simply cannot afford it yet, this is a good stopping point while I save up more money.  Rather than spending the money on a VF52, since I'll be done with it in a couple years anyway I might as well save the money as long as the VF30 doesn't completely suck in comparison.  I know the VF52 is awesome and I know I would be happy with it, I'm just making sure I wouldn't be completely UNhappy with the VF30- for now.  If it's even close to the same I'll be tickled pink.

I hope I can make more than 300whp with the VF30, I'm already at 270 with my stock VF40 (dyno tuned, I have a printout from a reputable shop, not just speculation).  For merely 30 more HP I don't think that's really worth my time.

Edited November 2, 2022 by RecklessWOT

[RecklessWOT]

I do pick up what you guys are putting down though.  It is a slightly older turbo so I guess I won't find much info here about it because people have moved on.  I suppose I'll go for it and report back if it might benefit anyone in the future. 

Sounds like from what you guys are saying some dudes used to run the VF30 but that info seems to be lost to the ages.  I tried looking before I even posted but it was no use.  I guess ever since switching away from trusty old VBulliten to this new weird cellphone app looking thing the search function can't go back in time.  Darn shame, internet used to be a wealth of information, but unless it's super current it all gets buried in algorithms these days. 

Should've known this website that was created with 4th gen Legacy GTs in mind would be the wrong place to go, heck I'm positive I've seen threads with people raving about how awesone the new soltera EV will be .  People keep telling me to check out NASIOC, but last I checked I don't own an Impreza (or respect most of the people who drive them lolol), so I guess I'll just stick to my old ways and finally learn my lesson about relying on the internet for real life stuff.  I'll call some old school Subaru shops and talk with old heads at car shows and stuff.  Wish me luck guys

(BTW, before anyone's undergarments get bunched up, I'm being ironically sarcastic because I'm frustrated.  Please nobody get mad, I know last time I was on here I made a comment that got some wagon driving skinny jean wearing handlebar mustache having hipsters all offended, feelings be so touchy on the internet these days.  Just chill I'm sorry for having emotions other than happiness lol)

[TMBLKDG]

Good luck!

I kinda get where you're coming from - it's a little weird to me that information about older combos and parts is so hard to dredge up, but I'm coming from the world of old-school American muscle.  My first automotive love was a Pontiac and I still own two of them - a '73 Firebird Esprit and a '72 Formula 400 Firebird that my dad bought brand-new and I bought it from him in 1985 when I was a Senior in High School.  Even though these cars are 50 years old I can go to a couple different forums and get answers to just about any question I might have about them and info on even older Pontiacs, back to the '50s, is still readily available.  The Subaru scene doesn't attract as many people devoted to the older models it seems, the interest in keeping the older cars running and fixing up/restoring them just isn't there like it is in the musclecar scene.  Reading through this forum you find a couple threads from guys who are totally rebuilding 4th gens, but it's an oddity, not the norm.  I've come to realize that my desire to drive an '05 GT Wagon that has been fixed up and made like new (but faster and better handling) is kind of an oddity.  The newer cars seem to draw a lot more attention and people are willing to part out/throw away cars in conditions that if they were an old Pontiac someone would be spending silly money to restore them.

So, I would say in your specific situation, the fact that people used to run those turbos and there doesn't seem to be any significantly negative info about them out there that they're probably fine, just old and outdated and fairly rare.  Since it's just a temporary deal and you can do it for cheap, go for it.

[RecklessWOT]

7 hours ago, TMBLKDG said:

Good luck!

I kinda get where you're coming from - it's a little weird to me that information about older combos and parts is so hard to dredge up, but I'm coming from the world of old-school American muscle.  My first automotive love was a Pontiac and I still own two of them - a '73 Firebird Esprit and a '72 Formula 400 Firebird that my dad bought brand-new and I bought it from him in 1985 when I was a Senior in High School.  Even though these cars are 50 years old I can go to a couple different forums and get answers to just about any question I might have about them and info on even older Pontiacs, back to the '50s, is still readily available.  The Subaru scene doesn't attract as many people devoted to the older models it seems, the interest in keeping the older cars running and fixing up/restoring them just isn't there like it is in the musclecar scene.  Reading through this forum you find a couple threads from guys who are totally rebuilding 4th gens, but it's an oddity, not the norm.  I've come to realize that my desire to drive an '05 GT Wagon that has been fixed up and made like new (but faster and better handling) is kind of an oddity.  The newer cars seem to draw a lot more attention and people are willing to part out/throw away cars in conditions that if they were an old Pontiac someone would be spending silly money to restore them.

So, I would say in your specific situation, the fact that people used to run those turbos and there doesn't seem to be any significantly negative info about them out there that they're probably fine, just old and outdated and fairly rare.  Since it's just a temporary deal and you can do it for cheap, go for it.

Hah, yeah me too.  I have been into japanese cars since I was younger (though generally older stuff from the 80s/early 90s) mailny because they were cheaper and easier to work on than American stuff, but I also do love old American iron as well.  I currently also own a basket case of a '79 T/A (with a 400 from a '73) Pontiacs have always been my favorite.  I've also got an old squarebody chevy truck, and a Jeep CJ.  Same thing as you, any info I need is ALL OVER THE PLACE, not hard to find in the least bit.  However this 17 year old car (which in my book ain't even that old, it's the second newest in my fleet besides my work truck lol) it seems like just because it's not new anymore people have just moved on.  Even the old Jap stuff, I can find tons of info on my Datsuns and it was plentiful when I used to run old Toyotas (guarantee all that info is still out there too).  The Subaru crowd seems to work differently than most in that aspect, and I even notice that a lot of people on these forums (not all) seem to have a much different attitude than people in those other places.  Like most car forums even if you mention something uncommon or old, people are like "wow cool sounds awesome, here let me link you to something useful", but around here people are like "oh gawd that's so old, get with the times"... smh.

But yeah like you said, I'm just gonna go for it.  Can't hurt, the price is right and I'm not sticking with it forever.  I'll report back to sprinkle some of that uncommon info back in here in case some weirdo like me comes in here looking for it later on.

Edited November 3, 2022 by RecklessWOT

[Max Capacity]

I understand, budget, stick to it.  This is a stepping stone for you, one step at a time.

Hopefully you'll keep us updated.

[Rusty9]

Anyways, it's not a BAD turbo per-se, it's just 20 year old tech. Sure my 40" Sorny Trinitron Tube TV was great in 1997 but I wouldn't choose it over a 40" flat panel if they were next to each other

Use whatcha got and make a cool car!