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Old 03-07-2019, 10:10 AM   #1
shemoves
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Default What turbo for 320 whp

With a new stock block STi (2005), what turbo would make 320whp (+/- 10) on 91 octane and a safe tune? I prefer ball bearing, and am willing to spend more for quality/reliability.
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Old 03-07-2019, 10:25 AM   #2
Turpid Porpoise
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I made 335whp on the stock VF turbo in my 2008. 91 octane is your limiting factor here so I'd recommend a meth injection kit rather than a larger turbo.
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Old 03-07-2019, 10:26 AM   #3
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16G, HTA68 HTA71, FP Blue would be the best bet for a wide powerband and good driveability. And if you ever want to go bigger the HTA 71/FP Blue can push 350-370whp
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Old 03-07-2019, 12:02 PM   #4
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I made 409whp on 93 octane with an FP Blue but the spool is not comparable to a stock turbo and is definitely overkill for 320whp.
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Old 03-07-2019, 12:19 PM   #5
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Kinugawa 16g or hta68

Kinugawa just released ball bearing 16-20g and those would be my choice
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Old 03-07-2019, 12:46 PM   #6
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currently at 316 on vf48...91 octane as well
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Old 03-07-2019, 02:42 PM   #7
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Thanks for the responses. I'm really only looking for 91 octane results. Would the stock intercooler be sufficient with either of the HTA's? How would a 20g XTR compare?
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Old 03-07-2019, 05:22 PM   #8
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Do you have full bolt ons? You should be within 10whp of your goal with full bolt ons and a protune. I really think you’re going to sacrifice spool, and therefore low end TQ, to acheive a few extra HP that you wont even notice.
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Old 03-08-2019, 09:37 AM   #9
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fuel system upgrade, CAI, TBE (with high flow cat), stock intercooler (might be open to upgrading the intercooler if it will help a lot).

The 71hta may work, even though it isn't ball bearing. How would a 18g compare to the 71 with 91 octane and stock intercooler?

I'd be willing to give up a bit of peak power for the sake of a much broader powerband and earlier spool.

https://goo.gl/images/86EVyv

Last edited by shemoves; 03-08-2019 at 10:02 AM.
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Old 03-08-2019, 09:52 AM   #10
Turpid Porpoise
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The stock intercooler is not a restriction until upwards of 400whp and you will not see any measurable gains just by switching cores.

All you need is a quality ELH, swapping turbos to hit 310whp is overkill and IMO will negatively impact the driving experience.
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Old 03-08-2019, 10:11 AM   #11
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Quote:
Originally Posted by Turpid Porpoise View Post
The stock intercooler is not a restriction until upwards of 400whp and you will not see any measurable gains just by switching cores.

All you need is a quality ELH, swapping turbos to hit 310whp is overkill and IMO will negatively impact the driving experience.
I did 270 whp on my vf39 back in '05 with just a catted TBE and tune on 91 octane, 300 whp on 100. I am going to be having an engine built and getting a new turbo. Based on dyno graphs I've seen, a 16g seems too small.
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Old 03-08-2019, 10:19 AM   #12
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You could go for a VF39.. it spools very quickly and has a lot of midrange torque but it kinda runs outta breath higher into the RPM range. With your engine though, you could easily get 320 out of it with supporting mods.
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Old 03-08-2019, 03:46 PM   #13
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Quote:
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You could go for a VF39.. it spools very quickly and has a lot of midrange torque but it kinda runs outta breath higher into the RPM range. With your engine though, you could easily get 320 out of it with supporting mods.
On 91 octane without injection?
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Old 03-08-2019, 04:07 PM   #14
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Just go with a 20G XTR, will get you to your goal with minimal lag.
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Old 03-08-2019, 10:44 PM   #15
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Why not 18g?
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Old 03-09-2019, 09:42 AM   #16
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Water/meth on stock turbo will get you there.
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Old 03-10-2019, 01:57 AM   #17
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Quote:
Originally Posted by shemoves View Post
Why not 18g?
On an STI with 91 octane - I think you'd be close with an 18G. 20G would be safer, but 18G might get you there. It's a small trade off, do you want slightly less lag, or slightly more top end.
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Old 03-10-2019, 12:53 PM   #18
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I won't be doing injection. Are the Blouch turbos well built? If i went non-ball bearing, is there a similar or better turbo for less $ than an XT?
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Old 03-10-2019, 02:04 PM   #19
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Quote:
Originally Posted by shemoves View Post
I won't be doing injection. Are the Blouch turbos well built? If i went non-ball bearing, is there a similar or better turbo for less $ than an XT?


I love my Blouch turbo. I have a 16G-XT on a 2.0 in my wagon that made 309awhp on a Dyno Dynamics dyno with a Dom Tune. A really good tune goes a long way and you should be able to hit your goals with the 18G-XT or XT-R if you’re set on using a ball bearing turbo.
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Old 03-10-2019, 09:32 PM   #20
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Do you think the engine will hold up through 100k miles at that power level? Would a built block last longer?
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Old 03-10-2019, 10:42 PM   #21
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Somethings to consider:

1. I've owned a Blouch small 16G (journal bearing), and a Blouch 18G XTR (ball bearing), and FP Blue (journal bearing). My opinion is I felt no noticeable difference in having a ball bearing vs journal bearing turbo.

2. You asked about Blouch and its competition. The FP turbo is my favorite by far. But it's not apples to apples when I say that. I had the 16G and 18G XTR on a stock hybrid engine. The FP Blue is on an IAG built engine with cams and +1 mm valves. So, I don't know what I'd say if I compared the FP Blue to the Blouch turbos on my old stock engine.

3. Last, and I didn't consider this in my first response, you're looking at possibly going from a VF turbo to an 18G turbo. That seems like a waste. It's a very small bump in power from the VF to 18G. You probably want to start with at least a 20G. But I would go just a hair bigger if I were you and get the FP 71HTA, and save a couple hundred off the Blouch turbo price.
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Old 03-10-2019, 11:39 PM   #22
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I got 270 whp on my vf39 using 91 octane, so i figured 40-50 whp would be a nice bump. Would a stock block hold up to a 20g for 100k miles?
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Old 03-11-2019, 12:47 PM   #23
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Quote:
Originally Posted by shemoves View Post
With a new stock block STi (2005), what turbo would make 320whp (+/- 10) on 91 octane and a safe tune? I prefer ball bearing, and am willing to spend more for quality/reliability.
if you are stuck with 91oct, 1.5xtr gets you to 350whp on very conservative tune. torque comes on very quick at 375wtq for me. On 93oct ive seen this turbo break 400whp.
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Old 03-11-2019, 02:13 PM   #24
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I'm not too familiar with what kind of power 91 puts down, but you should be able to get that with the stock turbo. I put down 319/365 on the stock turbo on 93 octane. What other mods are you running?

Edit: I agree with others saying it would be foolish to drop the stock turbo at that small amount of power. The stock turbo gives you a LOT of low end power because it spools so quickly.
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Old 03-11-2019, 02:21 PM   #25
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Quote:
Originally Posted by frugalrhombus View Post
I'm not too familiar with what kind of power 91 puts down, but you should be able to get that with the stock turbo. I put down 319/365 on the stock turbo on 93 octane. What other mods are you running?

Edit: I agree with others saying it would be foolish to drop the stock turbo at that small amount of power. The stock turbo gives you a LOT of low end power because it spools so quickly.
It's also just a number... chasing numbers is an easy way to not love the car you end up with.
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