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Old 04-07-2021, 05:44 PM   #1
4eat05
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Default Anybody use vf48 "hi flow"?

Hey all, I'm curious who all has used the ihi vf48 hi flow turbo?

Currently have vf39 and dark blue sti injectors (and all other supporting mods) on my 05 Wrx ej205, but i started seeing blue smoke out the exhaust and suspect the ooolld vf39 is on its way out.

I was thinking about just picking up a used vf48, then decided I might as well buy new in hopes of it lasting longer. Then noticed ihi offers the hi flow vf48.

Anyone have experience with both vf48 and vf48 hi flow?
Will my current dark blue injectors and walbro 255 be enough?
I just want to swap turbo and re-tune.
Not looking to re-replace injectors or fuel pump.

I'd really like to hear from anyone that has used it. Especially if you've used both vf48s.
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Last edited by 4eat05; 04-07-2021 at 05:50 PM.
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Old 04-07-2021, 10:38 PM   #2
K3rm1tth3fr0g
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After I heard about the HF version of the VF48 I became curious about it and other high performance VF variants available in 2021 and after speaking with my tuner about it and learning about IHI's US branch, if I were to spend money on a new OEM turbo, id get a VF34 from IHI's US sales department, Clover Turbo. The VF34 flows similarly to the VF48 but is ball bearing so it spools a good bit faster. The difference in peak power between the VF34 and VF48HF should be minimal and more than made up for by the decreased spool time in the VF34.

Walrbo 255 pump will be fine and STI injectors should be enough but personally I'd go larger like 1050Xs to allow you to run flex fuel if you so choose and avoid running out of fuel at high rpm.

https://turboturbos.com/products/vf34

I think Clover turbo just changed their name in the US to IHI FWIW.

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Old 04-07-2021, 10:43 PM   #3
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Do you happen to have a link to brand new vf34?

Not really interested in changing injectors again any time soon
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Old 04-07-2021, 10:52 PM   #4
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yup it was in the post hiding in the middle

https://turboturbos.com/products/vf34
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Old 04-08-2021, 12:22 AM   #5
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Had a VF34 on my last 205. Great turbo for that engine. Had dark blue STi injectors. Did max them out before we reached full potential from the turbo, but there wasn't much left. I had AVCS on that engine, but my power band was 3100-6200 rpm. Without AVCS you'll reach full boost a few hundred later
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Old 04-08-2021, 06:16 AM   #6
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Go search on IWSTI. There is a thread in there with dyno plots. The cliff notes are same spool as VF48, but more power.
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Old 04-08-2021, 07:27 AM   #7
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Quote:
Originally Posted by K3rm1tth3fr0g View Post
yup it was in the post hiding in the middle

https://turboturbos.com/products/vf34
Is that brand new?
I clicked on that link but assumed it was rebuilt/remanned since it had that green tag on it
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Old 04-08-2021, 08:05 AM   #8
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Quote:
Originally Posted by 4eat05 View Post
Is that brand new?
I clicked on that link but assumed it was rebuilt/remanned since it had that green tag on it

Its brand new. I asked my tuner that exact question because I was curious of the same thing. But Clover Turbo is just IHI's name in the US.

Last edited by K3rm1tth3fr0g; 04-08-2021 at 08:34 AM.
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Old 04-08-2021, 09:42 AM   #9
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And you would pick vf34 over vf48 hi flow for a non avcs usdm ej205?

I should be able to use my current sti 565cc injectors and walbro 255?

I always thought the consensus was vf39/43/48 was better for the 2.0 because the exhaust housing was smaller? (P17 vs p18?)
Did I read wrong?
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Old 04-08-2021, 09:45 AM   #10
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Quote:
Originally Posted by 4eat05 View Post
And you would pick vf34 over vf48 hi flow for a non avcs usdm ej205?

I should be able to use my current sti 565cc injectors and walbro 255?

I always thought the consensus was vf39/43/48 was better for the 2.0 because the exhaust housing was smaller? (P17 vs p18?)
Did I read wrong?
Its mostly personal choice, the VF48 HF will make a bit more power up top but spool a few hundred RPM later than the VF34.

The STI injectors, Walbro pump + a good tune will do you just fine.

For non AVCS 2.0s I'd definitely go ball bearing.

Last edited by K3rm1tth3fr0g; 04-08-2021 at 09:53 AM.
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Old 04-08-2021, 11:34 AM   #11
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IMO, especially with the 4EAT, I would look for more top end and raise the WOT shift points to near redline and not worry about a few hundred rpm spool. The VF34 powerband mentioned above (3100-6200) sounds like what you'd expect from a normal VF. Great midrange, but falls off up top. With the HF it should carry that a little closer to the 7k redline. I think you'd see more improvement keeping the gains higher in the rev range with the 2L. I'd lean towards the VF48HF, you'll likely be able to have it tuned with the current injectors, but I'd feel better with lower IDCs with 650-850's.

Ball bearing helps with transient response (off/on throttle when RPMs are above boost threshold.) Spool is down to wheel sizing and A/R. With the 4EAT you're not lifting to shift, so the transient response doesn't matter as much.
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Old 04-08-2021, 11:40 AM   #12
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I wouldnt want to run a VF48 HF with stock STI injectors personally, and he noted he wants to keep current injectors. The gains up top you'd see with the VF48HF would probably need larger injectors to capitalize on in a meaningful way anyway. Sticking with the STI injectors, I'd still prefer a VF34 if its going on a 205 w/o AVCS.
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Old 04-08-2021, 02:10 PM   #13
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I ordered the VF34 for my EJ207 last week from Turboturbos. Took 2 days to arrive!

I would get right to the point with the VF34. The response is fantastic and peak power is great.
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Old 04-08-2021, 02:17 PM   #14
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With a larger injector like a 650 or 850, I bet the 34 and 48HF would flow very close up top. I was limited with the STi injectors which we topped out at 95% just to leave them with a little buffer. As mentioned, with the 4EAT the transient response isn't that much of a benefit. Personally, I'd go for which ever one fit the budget. But then again for the price of a new IHI turbo, I'd go 16g and definitely have that top end that the VFs don't do as well. Which a 16g even on STi injectors should still out perform a 34/39/48. There will just be room to grow once the OP wants new injectors.
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Old 04-08-2021, 02:36 PM   #15
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I run 850cc injectors with a vf48 on an ej207, no need to push beyond 7000 rpm. Pink injectors were maxed out on top end, best to play it safe and upsize the injectors. The vf48 I have is not a high flow, it just has the SoCal porting treatment.
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Old 04-08-2021, 03:13 PM   #16
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Quote:
Originally Posted by snow_bound26 View Post
With a larger injector like a 650 or 850, I bet the 34 and 48HF would flow very close up top. I was limited with the STi injectors which we topped out at 95% just to leave them with a little buffer. As mentioned, with the 4EAT the transient response isn't that much of a benefit. Personally, I'd go for which ever one fit the budget. But then again for the price of a new IHI turbo, I'd go 16g and definitely have that top end that the VFs don't do as well. Which a 16g even on STi injectors should still out perform a 34/39/48. There will just be room to grow once the OP wants new injectors.

imo 16G would def be a better option if he was up-sizing injectors and doesn't care if it's OEM or not.

One other thing to note when comparing a 16g in this situation is pricing.

A standard jb BPT 16g is around 1k, same price as a new VF34 from IHI in 2021. But the VF34 is ball bearing. To get a ball bearing 16g you're spending upwards of $1500. Just worth mentioning.

Last edited by K3rm1tth3fr0g; 04-09-2021 at 10:20 AM.
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Old 04-09-2021, 03:27 AM   #17
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Quote:
Originally Posted by K3rm1tth3fr0g View Post
imo 16G would def be a better option if he was up-sizing injectors and doesn't care if it's OEM or not.

One other thing to note when comparing a 16g in this situation is pricing.

A standard jb BPT 16g is around 1k, same price as a new vf43 from IHI in 2021. But the Vf43 is ball bearing. To get a ball bearing 16g you're spending upwards of $1500. Just worth mentioning.


Vf34 is a ball bearing turbo, vf43 is a journal bearing turbo.
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Old 04-09-2021, 10:19 AM   #18
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Quote:
Originally Posted by D-Rodman View Post
Vf34 is a ball bearing turbo, vf43 is a journal bearing turbo.
Typo. Thanks for pointing that out.
VF34

Last edited by K3rm1tth3fr0g; 04-09-2021 at 10:24 AM.
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Old 04-09-2021, 10:28 AM   #19
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has anyone done a billet wheel upgrade on their vf34?
What were the results on spool, response, and top end if you have?
such as. https://turboturbos.com/products/mfs...d58bc27c&_ss=r
Also please note if it is a 6+6, 11 blade, etc.

Last edited by Craig4g63; 04-09-2021 at 11:11 AM. Reason: added link
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Old 04-09-2021, 04:09 PM   #20
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Quote:
Originally Posted by Craig4g63 View Post
has anyone done a billet wheel upgrade on their vf34?
What were the results on spool, response, and top end if you have?
such as. https://turboturbos.com/products/mfs...d58bc27c&_ss=r
Also please note if it is a 6+6, 11 blade, etc.


Had a 6x6 billet wheel on mine. Didn't use the turbo with the OEM wheel so I can't compare. I ran out of top end because I didn't have enough injector to keep it going, but I was fairly close to maxing out the turbo. My power band went to 6200. Probably could've pushed it to 6500-6600 with larger injectors.
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