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Old 09-14-2004, 01:18 AM   #1
trail*of*dead
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Default Most reliable way to reach 300 - 350 whp on a STi?

i can't really picture myself wanting much more than that to the wheels, but for me it is all about reliability and driveability so even around 300 to the wheels would probably be fine. all modifications aren't created equal, and it seems that certain modifcation paths are more risky than others.

so far i have just been reading and seeing other peoples mistakes and trying to choose the best path for myself. if possible i would like to keep my car with the same no lag feel that it has now. the dragstrip where i go is only 1/8th mi and some cars with bigger turbos , don't really get to use them to there full potential.

i would be happy with something that would have no trouble beating the lightly/ to heavily modded cars that i face now. right now i can run the 1/8th in 8.5 - 8.6, some practice would get the time down a couple more tenths, i am looking to be down to around anywhere between 7.9 and lower.
in any case thank you for reading and any advice would be much appreciated.
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Last edited by trail*of*dead; 09-14-2004 at 01:27 PM.
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Old 09-14-2004, 01:20 AM   #2
WRX Jim
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300 can be reached with turboback/utec,

i dont know what my numbers are

but my 1/8 is 8.1 with turboback/utec.
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Old 09-14-2004, 01:49 AM   #3
trail*of*dead
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i guess 350 at the wheels on pump gas would be a nice goal, i think that means that i would have to up the turbo size from what i have read. i just really don't know a whole lot about turbos and the correct way to choose one for my application.
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Old 09-14-2004, 02:02 AM   #4
WRX Jim
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green, modded injectors, turboback, walbro and utec.
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Old 09-14-2004, 02:19 AM   #5
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I'm of a similar vane. I think that's right, engine management of some kind with give you around 35-40 whp and a 3 in exhaust from the turbo back another 10-15 whp. A larger intercooler or front mount intercooler or water injection another 20-25 whp with a good deal of safety margin. You would still be in the operating range of the stock transmission components and might find your fuel economy improves if you lay off the right foot. Headers would give you more high end power, but at the expense of some spool and the possible quirks of headers due to there lighter weight and torsional strain.

For me, I'm using similar components and I'm hoping for about 325 whp total. Down the road I may upgrade the turbo for some added flexibilty should I want to spend more time on the track or at altitude.

I think engine management is a fairly personal choice with very similar power gains using any of them. Some systems better preserve stock functions than others, and others have greater flexibilty at the expense of self correction.

I'd look for a shop in your area and listen to what they propose; you can always test their ideas out on these boards for a more broad perspective. The only performance shop I know near Tennesee is SMC Enterprises in Cadiz, KY. Steve Chlupsa is there and seems like a very knowledgeable and helpful guy that is familiar with WRX/STI. I bought some nifty exhaust gas thermocouples from him. He's maybe two hours from you, north and west of Nashville. Also nearby is 3SX Performance in Concord, NC. They specialize in DSM cars, but I imagine they could, at the very least, give you advice on parts, install, other local shops. Good luck.
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Old 09-14-2004, 02:43 AM   #6
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XEDE with turboback will get you 310-320whp. Maybe 10 more if cat-less. Up to 350whp (dynojet) if runnning a race gas map with race gas.

shiv
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Old 09-14-2004, 10:00 AM   #7
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whats EXED??
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Old 09-14-2004, 10:01 AM   #8
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sorry i meant XEDE???
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Old 09-14-2004, 10:07 AM   #9
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Vishnu's form of engine management.
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Old 09-14-2004, 10:41 AM   #10
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Watching Tuner Transformation the other day a larger fuel pump, ECUtech, APS FMIC and a CAI (I disagreed with that one) led to 300 wheel torque and 273 whp on an '04 STi.

-J
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Old 09-14-2004, 12:31 PM   #11
trail*of*dead
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Quote:
Originally Posted by WRX Jim
green, modded injectors, turboback, walbro and utec.
couple questions about this.
what are common hp #s associated with these mods?
how does changing to a green affect the cars boost lag?
how much would this set me back?
would it be something that i could do on my own, or would i need to take it to someone to install?
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Old 09-14-2004, 12:35 PM   #12
WRX Jim
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your car bone stock vs green, full turbobck, utec ..lag would be identical to a stock car.

commen numbers.. ive seen up to 400+ awhp on pump.. commenly its around 350ish depending on your setup.

3800 dollars or so

you can do it on your own if your mechanically inclined. Of course you would have to pay for a tune ....
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Old 09-14-2004, 01:26 PM   #13
trail*of*dead
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Quote:
Originally Posted by WRX Jim
you can do it on your own if your mechanically inclined. Of course you would have to pay for a tune ....
well so far i have done all of my modifications. but those were on n/a cars that had a lot more working space in them. probably with some instruction i might be up to it. when you say that i would have to pay for a tune, i am assuming that you mean with utec. what is involved with that? i mean i have read some about utec, i just don't trust my knowledge on it enough.
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Old 09-14-2004, 02:32 PM   #14
WRX Jim
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a wideband and reading the manuel will really help if you want to tune yourself...
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Old 09-14-2004, 03:50 PM   #15
trail*of*dead
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i don't know if i would trust myself to tune it. would a standalone EM setup be worth me spending extra money on, or would utec be all i need to reach my hp goals?
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Old 09-14-2004, 04:29 PM   #16
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utec will work just fine.
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Old 09-15-2004, 02:25 PM   #17
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Arent you guys telling him green, injectors, turbo back, and em for like $3800 forgetting intercooler and fuel pump? Should be more like $5500 Right?
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