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Old 06-17-2004, 01:34 AM   #1
dorao
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Default STi Turbo Upgrade - Recommendations?

I realize there are a bunch of these threads and I apologize if I missed the thread that has my answer...

I had a txs stage 4 wrx; parted it and traded it in for an 05 STi. I'm slowly starting to migrate parts and find replacements for what wasn't compatible (going to go with the PE850 injectors and the Element this time). Now I'm looking for a new turbo to put on to it (had a VF34 on the wrx). I'm looking to have a +300whp on 93oct, daily driven, occasional track day, often auto-x'ed vehicle. I didn't like the vf34 on the wrx as the lag hindered it too much for auto-x and I would like it to spool as quick as possible but also hold boost to red line. As it is a daily driven vehicle, I was thinking of running ~19psi of boost as well, like I did on the wrx w/ the vf34...

Which turbos do you guys recommend? I wish there were dyno results with various turbos on the sti, but I'm getting anxious .

Thanks in advance,
Masuo
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Old 06-17-2004, 01:55 AM   #2
kenlee
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Sounds like your looking for a worked vf22, ( deadbolt...pe comp wheel and bigger spring). On pump you should have no problem hitting your goal of 300+whp. With race gas or water injection you would be closer to the 320-335whp range with proper timing advance and boost raised to say 20 or so psi. Good luck!
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Old 06-17-2004, 07:20 AM   #3
happasaiyan
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hmm...you can either keep the stocker on there or put a vf34 on there. spool and responsiveness will be nice on those and will both get you over 300whp.

if you want a nice auto-x car, check out getting a jdm header and a vf37. twin scroll = silly spool and responsiveness. can you say over 1bar by 2500?
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Old 06-17-2004, 07:49 AM   #4
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I've pretty much settled on a GT30.. it will need a little fab.. or if God gets his 'kit' out.. all the better.
but much cheaper than an SR50 (same thing). should be good for 350whp with a good tune and boost quickly.
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Old 06-17-2004, 09:09 AM   #5
WRX Jim
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dont use another IHI turbo, they are all too similar

Go FP GREEN
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Old 06-17-2004, 09:48 AM   #6
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i am thinking more and more about a vf-22 when i do upgrade. i had one on my wrx and i loved it, but i think it would be a better match for the 2.5, and at under $600 how can you go wrong?
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Old 06-17-2004, 10:00 AM   #7
WRX Jim
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vf22 couldnt hold boost on my 2.0 WRX, how could it hold much more in my 2.5... doesnt make sense to me.
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Old 06-17-2004, 10:53 AM   #8
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he said he wants 300whp. the stock one does that. he wants it to spool as quick as possible. the vf39 spools by 3000 and is very RESPONSIVE. what bigger turbo is going to do that without going twin scroll?

the green definately isnt going to be an auto-x turbo.
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Old 06-17-2004, 11:19 AM   #9
WRX Jim
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o..lol.. 300 awhp? thats acheivable with just turboback and engine managment
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Old 06-17-2004, 11:31 AM   #10
happasaiyan
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exactly.
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Old 06-17-2004, 11:36 AM   #11
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Quote:
Originally posted by WRX Jim
vf22 couldnt hold boost on my 2.0 WRX, how could it hold much more in my 2.5... doesnt make sense to me.
i never had a problem with mine at 21psi?


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Old 06-17-2004, 11:58 AM   #12
WRX Jim
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i made about 21 psi on my VF22 but it fell to about 17 psi by redline...

thats on my old stage 4+ wrx i used to own
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Old 06-17-2004, 12:05 PM   #13
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Quote:
Originally posted by WRX Jim
i made about 21 psi on my VF22 but it fell to about 17 psi by redline...

thats on my old stage 4+ wrx i used to own
If you change the WG actuator it'll hold boost till redline.
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Old 06-17-2004, 12:39 PM   #14
dorao
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Quote:
Originally posted by WRX Jim
o..lol.. 300 awhp? thats acheivable with just turboback and engine managment
+300whp means exactly what it states; *more* than 300whp (I'll take 500whp if it spools quick enough )

I'm more interested in getting into boost relatively quickly (<=3k rpm), and maintaining it to redline which the vf39/vf34 do not seem to do.

Thanks,
Masuo
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Old 06-17-2004, 01:18 PM   #15
Wombat North
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green


Quote:
Originally posted by nmyeti


Modifications:
TurboXS UTEC
TurboXS TBE (2.5 inch old school version)
TurboXS HPMBC
TurboXS Intake
Perrin modified injectors
FP Green
Walbro fuel pump

The lowest line is a stock STI. The middle (dotted red) line is the green on 21psi and pump gas. The highest line is at 28psi (falling to 23.8 at redline) on C16. The car would make more but the clutch won't take it. During this run the car kind of skipped a little on the dyno. I assumed it was the dyno acting a little funny, but it turns out it was the first signs that our clutch was on the way out. For the next run we cooled the car back down and turned up the boost to 29psi. The clutch completely let go as the boost hit 29psi. I havenít driven the car on the road yet, but I donít expect the clutch to hold in the higher gears. We need to get a replacement out here so we can take this thing to the track.

-Nathan
ps, no coils were harmed during this test
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Old 06-17-2004, 03:52 PM   #16
dorao
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Quote:
Originally posted by Wombat North
green
oo. *drool*


BTW, am I blind? I don't see the dotted red line that is supposed to be with pump gas @ 21psi

Thanks,
Masuo
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Old 06-17-2004, 04:13 PM   #17
T3RMIN4L
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Play with your brightness... its there but VERY hard to see.
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Old 06-17-2004, 05:09 PM   #18
happasaiyan
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yeah...hard to see on lcds
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Old 06-17-2004, 05:41 PM   #19
dorao
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Thanks, I see it now. very impressive.

Still would like something that would make power about 500rpm sooner though. Something a little smaller...

As was suggested by trent, I'll have to give FP a call and see if they'll make a smaller green .

decisions decisions; pe1818, pe1820, sr40, small green, FPWRX20G, etc...

Thanks,
Masuo

Last edited by dorao; 06-17-2004 at 06:00 PM.
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Old 06-17-2004, 05:48 PM   #20
STiLL WILL
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Masuo, if you want something smaller than a Green but will spool almost instantaneously, there's always the JDM STi twin scroll VF37 kit Mauro is installing on his STi. We already have the proper oil pan for the twin scroll equal length headers so there's a start!


-Matt
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Old 06-17-2004, 06:04 PM   #21
dorao
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Quote:
Originally posted by STiLL WILL
Masuo, if you want something smaller than a Green but will spool almost instantaneously, there's always the JDM STi twin scroll VF37 kit Mauro is installing on his STi. We already have the proper oil pan for the twin scroll equal length headers so there's a start!


-Matt
How much will it be all said and done?

Are there any dyno plots of the vf37 on a USDM STi?

(I pretty much ruled out twinscroll as I already had header, etc...)

Thanks,
Masuo
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Old 06-17-2004, 06:57 PM   #22
STiLL WILL
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Peep this thread for more info on the VF37:

http://forums.nasioc.com/forums/show...hreadid=552016


I'm pretty sure you'd absolutely LOVE it for auto-x considering how fast it spools up.



-Matt
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Old 06-17-2004, 07:00 PM   #23
wgknestrick
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Any turbo that doesn't have a "VF" in front of it.
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Old 06-17-2004, 09:44 PM   #24
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just wonderin

if u upgrade your turbo will u need to get a turbo timer afterwards for cooling it down?
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Old 06-17-2004, 11:42 PM   #25
dorao
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Quote:
Originally posted by JikJak
just wonderin

if u upgrade your turbo will u need to get a turbo timer afterwards for cooling it down?
Depends of its water & oil cooled; but I have a turbo timer that I was trying to sell laying around. Guy who wanted it had me hold it forever, then backed out on me at the last second... *grr*

Masuo
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