been looking around and there doesnt seem to be any discussion here or in the Aftermarket Turbo forum about using any of the popular 2.0 turbo upgrades on the STi(if a thread already exsists please point me to it!) So lets get the ball rolling, any real experience, solid info, or wild a$$ guesses welcomed:)

I'll get it started. I was hoping to use one of the affordable IHI turbos as an upgrade to our VF39, but had heard that there might not be any gains using any of the other VF turbos over ours, any ideas how the 39 stacks up to the 30/34 or 22?

The VF39 seems to flow about the same as a VF30/34. Therefore, the VF22 should give you a little more top end. There aren't many bigger bolt-on turbos that I can think of. Most of the commonly used big turbos require semi-custom up and downpipes and seperate wastegates and such.

thanks! Do you think a PE1818 or 20 would be worth it?

Originally posted by Krinkov
thanks! Do you think a PE1818 or 20 would be worth it?

I'd like to know this as well.

Originally posted by BAN SUVS
The VF39 seems to flow about the same as a VF30/34. Therefore, the VF22 should give you a little more top end. There aren't many bigger bolt-on turbos that I can think of. Most of the commonly used big turbos require semi-custom up and downpipes and seperate wastegates and such.



Ah don't know where you got that info? Any bolt-on wrx turbo will bolt on to the STI.

with the 2.5L you can spin large turbos easily

APS sr-50
AVo 450 or 500
pe 1820
fp green

There are more but those seem to be the movers these days.

I would stay away from any vf series as they max out at about 350 bhp

GO big! :banana:

Matt

so would any of those turbos be a straight bolt on afair just like a VF?

Originally posted by Krinkov
so would any of those turbos be a straight bolt on afair just like a VF?


Yes they will bolt in, some of them might have problems clearing the top mount I/C but if you are going to a bigger turbo you need a FMIC to get the most from the upgrade.

Matt

I've decided to go with a PE 1820 as soon as some engine management becomes available.

IMHO a good choice! I would now look at an I/C as The stock I/C is not capiable of cooling the charge.

M

PE1825 or STi Twin Scroll Turbo.

For big power freaks, GReddy T67 or HKS 2540.

Ideally, HKS 3037S.

Originally posted by bikerboy
IMHO a good choice! I would now look at an I/C as The stock I/C is not capiable of cooling the charge.

M

Going with a TXS FMIC as well. :banana:

Originally posted by Imprezer
PE1825 or STi Twin Scroll Turbo.

For big power freaks, GReddy T67 or HKS 2540.

Ideally, HKS 3037S.

Whoa! You can get like 3 PE1820s for the price of that HKS 3037S:eek:

Or you can buy about 485 Tornado Fuel Saver intake inserts. ;) Whats your point?

Originally posted by Imprezer
Or you can buy about 485 Tornado Fuel Saver intake inserts. ;) Whats your point?

hmmm... 485 tornados, thats like 7200 extra hp!:D

Originally posted by Krinkov
Whoa! You can get like 3 PE1820s for the price of that HKS 3037S:eek:

:D You know, there is a reason why HKS is also known as "HK$":banana:

You know, there is a reason why HKS is also known as "HK$"


No, I don't. ;) I do know that it is also known as "Da ****". ;)

---

Seriously though,

HKS GT3037S turbos retail at about $2300.
PE1825 retails at about $2480.
PE1820 and PE1818 retails at about $1800.

So there isn't much diff.

GT3037S is LOT BETTER turbo. There is no questions about it. When properly "trimmed" and "A/Red" that turbo will outperform nearly any turbo.

Originally posted by Imprezer
No, I don't. ;) I do know that it is also known as "Da ****". ;)


But HK$ "****" is consistently the most expensive out there, no matter what it is, be it their BOV, or their grounding kit for 200 bux:eek:

I am sure that their turbos are worth the cash, but I am not so sure about most of the rest of their product line....

I should have a SR50 (and all necessary supporting mods) in my STi and on the dyno by tomorrow...

Originally posted by cdraayer
I should have a SR50 (and all necessary supporting mods) in my STi and on the dyno by tomorrow...

What injectors? E-Manage? FCD? ... What are your other supporting mods?

Originally posted by STiDreams
What injectors? E-Manage? FCD? ... What are your other supporting mods?

APS DR650 FMIC
APS CAI
APS 3.5 TBE
APS BOV
APS Up-Pipe
Cusco Headers (4-2-1 equal length)
APS Tumbler-Delete Valve
APS Fuel Rails
Greddy 720cc injectors
Greddy e-Manage
Greddy Profec BII EBC
HKS FCD
(and some other stuff, and those are just the power mods...)

But HK$ "****" is consistently the most expensive out there, no matter what it is, be it their BOV, or their grounding kit for 200 bux


Yes, HKS is expensive, but there is a reason for that. HKS products are the highlest quality items with lots of R&D behind them.

And, please stop throwing #'s around if you have no clue what they are really are.

HKS "Circle Earth" grounding kit is $125. It uses 24k gold plated terminals and some special super conductor wires.

All in all, you get what you paid for.

anyone ever look into using the Garrett drop-in replacement turbos?

i think with their experience and modern aerodynamic designs, garrett turbos are some of the most efficient turbos on the market. for the EJ25, id recommend the GT22 internal WG or the slightly larger GT22 with an external WG from Turbometrics. Maybe even a GT32...

As for the HKS turbos, "Big Boss Man" is definately right. With the proper trim, the 3037S is a surefire killer. Especially on the larger displacement EJ25, the thing will RIP. HARD. Their quality is trend setting, and you absolutely DO get your money's worth. But when you get to the cost of HKS, at that level it's surely worth it.

JAN

Originally posted by cdraayer
APS DR650 FMIC
APS CAI
APS 3.5 TBE
APS BOV
APS Up-Pipe
Cusco Headers (4-2-1 equal length)
APS Tumbler-Delete Valve
APS Fuel Rails
Greddy 720cc injectors
Greddy e-Manage
Greddy Profec BII EBC
HKS FCD
(and some other stuff, and those are just the power mods...)

since you had the STi up-pipe off to look at, would it be worth replacing with an aftermarket piece? I know it doesnt have a pre-cat but did it seem at all restrictive? is there a reason you are using the APS one instead?

So far as I know, the SR50 may have required an up-pipe, as did the Cusco headers. As for the stocker, you are right that it doesn't have a cat - but boy is it ugly (the APS one is like a piece of art in comparison - considerably nicer/better than a HKS even). I'm not sure that the ugliness is inefficent in any way, but I can't imagine it is as efficent as the APS - especially when combined with the other APS bits.

Would I replace it if not in combination with other improvements? No.

Would I replace it if in combination with other improvements? Of course.

Take the stock exhaust or headers for example: they are designed by Subaru for maximum efficency - keeping in mind the respective restricitons placed upon them, their cost, and the diverse demographic who will be buying them. Towards these ends they work very well, but, if your only criteria was performace, something better could surely be made. Here companies like APS/HKS/Whoever step to the plate.

So, did my mods require the up-pipe? I'm not entirely certian, but it seemed silly to be changing everything else and to leave it stock.

thx!:cool:

I am working on a bolt on GT30R Garret ball bearing turbo but will not be ready until April or May. The GT25R based unit for the regular WRX will be ready this month though.

Originally posted by cdraayer
I should have a SR50 (and all necessary supporting mods) in my STi and on the dyno by tomorrow...

SR50 made 374.2whp/371wtq at 21lbs on race fuel, and 354whp at 18.5lbs on pump gas. Not bad for a 2.5L 4-cylinder...

Originally posted by cdraayer
SR50 made 374.2whp/371wtq at 21lbs on race fuel, and 354whp at 18.5lbs on pump gas. Not bad for a 2.5L 4-cylinder...

whoa!:banana:

what other mods??

Originally posted by cdraayer
APS DR650 FMIC
APS CAI
APS 3.5 TBE
APS BOV
APS Up-Pipe
Cusco Headers (4-2-1)
APS Tumbler-Delete Valve
APS Fuel Rails
Greddy 720cc injectors
Denso 320l/h fuel pump
Greddy e-Manage
Greddy Profec BII EBC
HKS FCD
(and some other stuff, and those are just the power mods...)

woops, heh, nevermind:p

Originally posted by cdraayer
SR50 made 374.2whp/371wtq at 21lbs on race fuel, and 354whp at 18.5lbs on pump gas. Not bad for a 2.5L 4-cylinder...

Pump = 93, 91 or .... ???

Originally posted by STiDreams
Pump = 93, 91 or .... ???

93, but only with the help of the advanced fuel system/engine management to keep the a/f ratios safe.

BTW, my car made 238 on this dyno when it was stock...+136whp!

cdraayer:

Could you address the conversion from the side feed setup to the APS setup? I have just about the same setup as you and was looking for what to do with the fuel system.

Matt

Well, I'm not real familiar with the specifics, but I do know that using the APS fuel rails allowed utilization of top-feed injectors (upposed to the side-feed stockers). We also used a stand-alone fuel pressure regulator, but I'm not sure exactly why or if it was absolutely necessary. Also, be aware that the stock fuel pump isn't all its cracked up to be - to make big numbers you are going to have to get something larger.

You can always contact www.mzmperformance.com for specifics, ask for Mohammad.

I know this is an old thread...but I have a few questions.
#1:
As far as the Fuel set up...if you were to make the stockers bigger, and get a bigger fuel pump, will the rest of the fuel system be good?

I already have Fuel rails, Fuel regulator and Steel Braided lines on my WRX. Just wondering if I should sell those or keep 'em...if I get an Sti ;)

#2:
Does anyone know the difference between the SR50, and a PE1820. I know the PE1820 has AWESOME high end, so would these be comparable? ( I already have the PE1820, again just seeing if I am going to use it on the STi...save money) :D

thanks

More questions to come :)

-freddie

i'd recommend a GT series turbo like a GT25r or GT35r....with a T3 compressor housing should be good for around 400hp. or if you wanted to go all out and shoot for 800hp GT4245 turbo....suckers got a GT42 compressor, and GT45 turbine housing haha :) ..

maybe if you dont like the lag with the T3 compressor housing you could do something like a T28 turbine housing (76 time) with T04S compressor (48 trim) with the GT25r. bet that would be a nice setup.

of course you'd more than likely need supporting mods with these aftermarket turbo(s)...

I know this is an old thread...but I have a few questions.
#1:
As far as the Fuel set up...if you were to make the stockers bigger, and get a bigger fuel pump, will the rest of the fuel system be good?

I already have Fuel rails, Fuel regulator and Steel Braided lines on my WRX. Just wondering if I should sell those or keep 'em...if I get an Sti ;)

#2:
Does anyone know the difference between the SR50, and a PE1820. I know the PE1820 has AWESOME high end, so would these be comparable? ( I already have the PE1820, again just seeing if I am going to use it on the STi...save money) :D

thanks

More questions to come :)

-freddie

#1. Yes, a bigger pump and injectors is about all you need, though if you already have bigger injectors AND perrin rails on your WRX you can use those on the STI. The STI uses side feed injectors and there arent any cheap injector upgrades out yet, a few guys are using regular top heed injectors with top feed rails and it works just fine.

#2. if you already have the 1820 I would just run that, but the SR50 OWNS the 1820. the SR50 is based on the Garrett GT series, the 1820, as you probably know, is just a VF22 with a custom compressor wheel.