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Old 02-07-2021, 01:04 AM   #1
Savage388
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Default Blouch 16g-xt vs vf52

After looking at all the stickies and talking to my tuner it looks like a blouch 16g-xt will meet my goals for low 300's
(on 93)and have more headroom than the stock vf52 but general opinion around the forums is "20g or dont bother". Since the Blouch flows much more than a normal 16g or what a vf39,48,52 is estimated, I should gain some midrange and top end without losing low rpm grunt?
Car is an 09 wrx
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id1050x
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Old 02-07-2021, 09:46 AM   #2
K3rm1tth3fr0g
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For the 2.5L, unless you want LIGHTNING SPOOL, id suggest at least an 18G, but lots of folks run 16Gs on their 2.5s, you just trade top end for response, the choice is yours.

Any new Blouch turbo (16, 18g etc) will outflow a non billet wheel, stock vf52. And the 16g and 18g will even spool better than the vf.

If you can swing it, the 16 and 18GXTR ball bearing versions spool even better, albeit at a higher price.

18GXTR would be what I would suggest if you can swing it and you want to balance top end and response.

Last edited by K3rm1tth3fr0g; 02-07-2021 at 12:04 PM.
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Old 02-07-2021, 12:18 PM   #3
motorbykemike
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The 16g is much better suited to the 2.0 even with the larger hot side option

On the 2.5 The 16gís are definitely kinda instaspooly and capable of actually being dangerous to the motor if tuned to their potential, the 18/20g coming in a little bit later but pulling hard up top are actually easier on the motor and more fun imho. Donít be afraid of lag , all these turbos are still considered small frame and are still quite peppy

An 18g or 20g with the largest hot side available from their respective suppliers would be better balanced on a 2.5

They also have potential for better mpgís if driven diligently

You already have injectors, and hopefully a pump already to support a turbo

Please list you entire current mod list

Where in pa are you ?

And also check out the turbos from bnr supercars , great products at a reasonable price
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Old 02-07-2021, 12:31 PM   #4
benflynn
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I would pick one that will hold boost till redline, I like to creep 2psi at the top keep curve strong, and add ewg
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Old 02-07-2021, 12:45 PM   #5
Hooverjc
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Agree with the others, as someone who is upgrading again, originally going from a td04 to vf48 and now to a 1.5xtr, don't waste your money going with a 16gxt as it's only marginally better than a vf48/vf52. The power will die off well before red line leaving you wanting more in no time at all.

Also remember that a hp goal is pointless, 300 hp on a 16gxt vs a 20gxt is not even comparable imo.
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Old 02-07-2021, 01:00 PM   #6
Savage388
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Quote:
Originally Posted by K3rm1tth3fr0g View Post
For the 2.5L, unless you want LIGHTNING SPOOL, id suggest at least an 18G, but lots of folks run 16Gs on their 2.5s, you just trade top end for response, the choice is yours.

Any new Blouch turbo (16, 18g etc) will outflow a non billet wheel, stock vf52. And the 16g and 18g will even spool better than the vf.

If you can swing it, the 16 and 18GXTR ball bearing versions spool even better, albeit at a higher price.

18GXTR would be what I would suggest if you can swing it and you want to balance top end and response.
I'd love to swing an 18g xtr but that is a bit out of budget, I'm just looking for a modest upgrade over my vf52 I have now it makes boost plenty quick but doesn't hold power as well as I'd like up top, Im still on a stock bottom end. I was going to send my vf to be ported/ machined out for a bigger wheel originally.

Quote:
Originally Posted by motorbykemike View Post
The 16g is much better suited to the 2.0 even with the larger hot side option

On the 2.5 The 16gís are definitely kinda instaspooly and capable of actually being dangerous to the motor if tuned to their potential, the 18/20g coming in a little bit later but pulling hard up top are actually easier on the motor and more fun imho. Donít be afraid of lag , all these turbos are still considered small frame and are still quite peppy

An 18g or 20g with the largest hot side available from their respective suppliers would be better balanced on a 2.5

They also have potential for better mpgís if driven diligently

You already have injectors, and hopefully a pump already to support a turbo

Please list you entire current mod list

Where in pa are you ?

And also check out the turbos from bnr supercars , great products at a reasonable price
I'm a bit east of pittsburgh in cambria county
Current mods
Cobb dp
Spt cbe
Aem 340lph
Id1050x
Cobb inlet
Cobb sf
Gs tmic
Cobb ebcs
Some suspension and brake stuff not related

I am a bit worried even the blouch 16g xt will choke up top worse than the vf even though all the measurements point that it's bigger.
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Old 02-07-2021, 01:06 PM   #7
Hooverjc
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I had my vf48 ported and with a larger wheel by socal porting. Peak power is better but it still dies really quick up top. The exhaust side of the turbo is just too small for the engine to breathe in the upper rpms which isn't addressed via a larger wheel.
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Old 02-07-2021, 01:14 PM   #8
Savage388
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Quote:
Originally Posted by Hooverjc View Post
I had my vf48 ported and with a larger wheel by socal porting. Peak power is better but it still dies really quick up top. The exhaust side of the turbo is just too small for the engine to breathe in the upper rpms which isn't addressed via a larger wheel.
That's the exact thing I was going to have done to my extra vf52 and what I was worried about as well. Still a 20g is too big for me, even on pump. Transient response takes a hit I don't like for how I drive, one of the reasons I didn't go fmic as well.
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Old 02-07-2021, 01:48 PM   #9
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Sounds like you are trying to stay on a budget , which is just fine

Have a Look at the bnr 18g

Less money than the Blouch 16g I think

And a proven performer, I have direct experience with two of their 16g , three of the 18 , they just work . Actually they overperformed and weíre pepier than advertised on all accounts. and a friend used their largest sti turbo on his wrx , came off a 52 and has zero complaints , saying similar things


Who is your tuner and your mod list did not say Cobb ap so I assume open source

You have enough pump and injector for way more than you will ever see with any of the 16 , 18 or 20g turbos on pump gas . Maybe consider flex fuel down the road
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Old 02-07-2021, 02:03 PM   #10
Savage388
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Sorry etuned by ed hawkins at fast performance, I do have an ap just failed to mention it as a mod. Yea i purposely went big on the fuel system in the event I wanted e85, right now it's a dd so I'm sticking to 93. I'll be looking at the bnr turbos 18g then unless I can get a deal on a blouch and selling my extra vf.
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Old 02-07-2021, 02:06 PM   #11
K3rm1tth3fr0g
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If you're on a budget, get your current turbo ported and machined for a bigger wheel.

Hill country forced induction can turn your VF52 into basically a 20G IIRC

Last edited by K3rm1tth3fr0g; 02-07-2021 at 03:53 PM.
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Old 02-08-2021, 08:48 AM   #12
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Stuffing a big compressor wheel in an otherwise stock vf results in an even larger imbalance because of the super restrictive hot side wheels and housings


Subaruís really like big hot sides , people get so wound up about spool ( see what I did there) that they often put too small of a hot side housing on a big turbo to help with spool , sure it spoils 200 rpm quicker maybe but it kills a thousand rpm of power up top and clips the wings off the hp achieved as well , itís just not reasonable as far as Iím concerned

Size the turbo to your needs and use a big hot side housing

Lag means your in the wrong gear

Just about any 16/18/20g on a Mitsubishi td05/h/hf turbine is going to be peppy on a 2.5 Subaru

Itís when they are on a td06 hot wheel is when they can be lazy , but at that point all but maybe a super badass trick 20g compressor is too small


Itís all about balance

And on a Subaru , it doesnít matter what your cousins sisters boyfriends dogs left nuts buddy did with his hondamitsuvwayota

We are talking subies
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Old 02-08-2021, 04:43 PM   #13
REX_WGN
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For what will be spent on a 16G, I think it would be best to go to at least a 20G from a VF turbo. But I think it comes down to what you want out of driveability. Bigger turbo always means you lose the low end torque punch but gain up top.

So I started from a TD04 to a VF43 with basic supporting mods. Then after a year or two, I went to a Blouch TD06-20GXT. If I had to do it again, I would've skipped the VF43. And I have no issues with driving around town. After a while, you learn what gear you need to shift down to if you really need to get on it. But that push near the top of the rev range is well worth it. And I'm planning on going to a 2.5XTR soon for more.

I'm just concerned you won't get as much top end as you'd like from a 16G or you won't notice the difference from the VF52. Maybe you can go to your local forums or Subaru FB groups and see if anyone has a 16G or a 20G turbo and ask for a ride. Just so you can feel the difference.

Stock internals is also a concern but I think we all know we pay to play. Start saving up for a built engine, even if it's just one with better pistons.
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Old 02-09-2021, 12:05 AM   #14
Savage388
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Quote:
Originally Posted by motorbykemike View Post
Stuffing a big compressor wheel in an otherwise stock vf results in an even larger imbalance because of the super restrictive hot side wheels and housings


Subaruís really like big hot sides , people get so wound up about spool ( see what I did there) that they often put too small of a hot side housing on a big turbo to help with spool , sure it spoils 200 rpm quicker maybe but it kills a thousand rpm of power up top and clips the wings off the hp achieved as well , itís just not reasonable as far as Iím concerned

Size the turbo to your needs and use a big hot side housing

Lag means your in the wrong gear

Just about any 16/18/20g on a Mitsubishi td05/h/hf turbine is going to be peppy on a 2.5 Subaru

Itís when they are on a td06 hot wheel is when they can be lazy , but at that point all but maybe a super badass trick 20g compressor is too small


Itís all about balance

And on a Subaru , it doesnít matter what your cousins sisters boyfriends dogs left nuts buddy did with his hondamitsuvwayota

We are talking subies
My goal is pretty much to have a balanced mountain runner dd, I have brakes and suspension figured out, it's time to make consistent power. As it sits now the vf has more than enough dig down low ( a little too much in 2nd) but if I stretch gears it falls a bit flat. I am looking for more useable power under the curve vs a higher peak that many people chase. I'm still on a stock block and trans so instead of looking to make power sooner I'm looking to stretch it higher, with the least timing/ boost I can get away with. That was my reasoning behind the 16gxt with that big hotside, I thought it'd flow enough over a vf to make a difference up top but not ruin response but it appears either blouch is either too optimistic on compressror flow ratings for a 16g or the vf turbos are underrated.



Quote:
Originally Posted by kenliu84 View Post
For what will be spent on a 16G, I think it would be best to go to at least a 20G from a VF turbo. But I think it comes down to what you want out of driveability. Bigger turbo always means you lose the low end torque punch but gain up top.

So I started from a TD04 to a VF43 with basic supporting mods. Then after a year or two, I went to a Blouch TD06-20GXT. If I had to do it again, I would've skipped the VF43. And I have no issues with driving around town. After a while, you learn what gear you need to shift down to if you really need to get on it. But that push near the top of the rev range is well worth it. And I'm planning on going to a 2.5XTR soon for more.

I'm just concerned you won't get as much top end as you'd like from a 16G or you won't notice the difference from the VF52. Maybe you can go to your local forums or Subaru FB groups and see if anyone has a 16G or a 20G turbo and ask for a ride. Just so you can feel the difference.

Stock internals is also a concern but I think we all know we pay to play. Start saving up for a built engine, even if it's just one with better pistons.
Money for the 16g isn't the real issue, I can get one for net $400 new 2nd hand after I sell my extra vf52.
I've had a couple grand set aside for a short block since I bought the car but it's a dd for a bit still so I want to keep it reasonable on the stock bottom end. I'm also a bit worried a 16g will not have any more top end than my vf. Around here everyone I know is either stock turbo or has a giant rotated iag built setup and I've meet many of the local Subaru people.
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Old 02-13-2021, 12:20 AM   #15
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My buddy made 349whp/400wtq in his 04 STI on 93 with the stock vf39, stock injectors, an inlet, turboback & methanol injection. Tuned by Agile.
****-your-pants spool time & torque, it was a blast to drive.
Fyi... I have a low mileage vf43 for sale and I'll have a similar low mileage Blouch 20G XT-R for sale in a week or two (bumping up to a Dom 3.0).

Last edited by Subie_; 02-13-2021 at 12:30 AM.
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Old 02-14-2021, 11:27 AM   #16
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Avo 420, really a gt2871r, I think would be small enough
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Old 02-22-2021, 01:51 PM   #17
Savage388
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Quote:
Originally Posted by Subie_ View Post
My buddy made 349whp/400wtq in his 04 STI on 93 with the stock vf39, stock injectors, an inlet, turboback & methanol injection. Tuned by Agile.
****-your-pants spool time & torque, it was a blast to drive.
Fyi... I have a low mileage vf43 for sale and I'll have a similar low mileage Blouch 20G XT-R for sale in a week or two (bumping up to a Dom 3.0).
A 20gxtr seems a bit big however I may be interested.
Quote:
Originally Posted by benflynn View Post
Avo 420, really a gt2871r, I think would be small enough
Really a gt2871r would be fantastic but price is a bit of an issue with the garrett turbos, especially if your not going big.
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Old 02-22-2021, 02:18 PM   #18
K3rm1tth3fr0g
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Quote:
Originally Posted by Savage388 View Post
A 20gxtr seems a bit big however I may be interested.Really a gt2871r would be fantastic but price is a bit of an issue with the garrett turbos, especially if your not going big.

20xtr will spool like a regular 18g with more topend
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