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Old 10-30-2005, 11:14 PM   #1
mannslayer
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Talking 02' 2.5 RS-T Build

Heres the current build for my rs-t :

Garrett T28 Turbo
Spearco TMIC
WRX Fuel Pump
WRX Injectors
Custom Catless Down/Up Pipe
Borla Headers
Custom Fuel Rails
TurboXS H-RFL BOV
K&N Air Intake
Sti Catback Exhaust
Apexi S-AFC II
TurboXS Dual Stage Boost Controller
Sti 2.5 Shortblock
TWE Stage II SOHC Cams
TWE Valve Springs / Ti Retainers


What do you guys think, any suggestions, anything I am missing? I am going to replace the S-AFC II with a PP or something similar. I am also going to do weight reduction and possibly a rollcage at some point. Will be running 94 octane daily at about 13 - 18 psi, and hopefully around 20 - 25 psi track, race, etc.
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Old 10-30-2005, 11:23 PM   #2
Master2192
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Hydra EMS, also the WRX injectors will not be big enough unless you mod them. TWE stuff is good.

But seriously you car will have trouble starting with unmodded WRX injectors on a 2.5L block. especially if you planned on using the stock ECU.

Also i think that turbo is alittle small to be trying to run more than 18 psi, it just can't flow enough

My build is going to consist of:
Sti Shortblock
Hydra EMS
Fuel Rail and injectors from outback motorsports (i've got a 98, hard to find injectors)
WRX crossmember, headers, uppipe, downpipe, turbo, tmic
Upgraded Radiator (The RS radiators are TOO small for alot of boost, atleast track runs anyway)
Walbro Fuel Pump
PPG 1-4 Straight Cut Synchro Gearset

Then later i'll upgrade the turbo with a rotated mount GT30R. Aiming for 400whp daily
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Old 10-31-2005, 12:48 AM   #3
mannslayer
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Yes, the wrx injectors have been modified. How important is a wrx crossmember, what exactly is it and what does it do?
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Old 10-31-2005, 01:58 AM   #4
Master2192
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The WRX crossmember allows you to use the WRX manifold, up pipe, and down pipe. You can also notch your crossmember instead but some say that weakens it. The reason is it has a notched area for the uppipe to go up.

I planned on using it because i'm going with WRX components, this makes it alot less custom and I can easily bolt things on later without going to a shop everytime to get something made.
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Old 10-31-2005, 03:18 AM   #5
Sko
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Also: Mabe upgrade your pistons before you upgrade your cams? STi pistons are good, don't get me wrong, but they aren't paired for the RS cylander heads, and TWE pistons will kick @ss.

I've actualy heard that TWE says the stock RS short block ain't too bad, and replacing the pistons, cams, and putting in titanium valve/retainer kit wouldn't be too bad of a way to go for high boost either.

Nick
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Old 10-31-2005, 08:42 AM   #6
Handsdown
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i'd agree, you're going to want standalone if you're doing cams and 20psi. a PP6 might be able to handle it but it won't handle it half as well as a standalone with some tuning time. with all the custom fabrication you should get a wideband o2 sensor anyway.

and yeah, the crossmember just allows the uppipe to fit. the wrx headers bolt right up to the sohc heads though, right?

twe cams/springs/retainers and 20psi will be crazy.
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Old 10-31-2005, 12:06 PM   #7
kgb
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The T28 is a little small for a 2.5L engine - it might be better to go a little bigger and run less boost (which would produce the same amount of compressed air but more efficient = cooler air)
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Old 10-31-2005, 12:09 PM   #8
2.5 Blue Roo
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fyi- if your using wrx headers/uppipe be aware of 2 things

first, the headers will not clear the N/A waterpump, youll have to install a turbo waterpump

second, apparently the wrx uppipe wont clear ther SOHC heads, therefore a spacer of about 1 inch is needed between the headers and uppipe to give it a good amount of clearance
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Old 10-31-2005, 09:04 PM   #9
wnabwrx
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I want to get more hp out of my 05 rs but not many companys make stuff for it. what do i do?
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Old 11-01-2005, 10:59 AM   #10
kgb
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Quote:
Originally Posted by wnabwrx
I want to get more hp out of my 05 rs but not many companys make stuff for it. what do i do?
Seriously, just save up and trade to a 06 WRX which gives you a 2.5L engine. Even if you don't like the styling, find a 05 WRX on the lot and trade for that it will still give you a better base to start modding for power
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Old 11-01-2005, 06:51 PM   #11
mannslayer
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What turbo should I replace the GT28 with? GT30R?
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Old 11-02-2005, 02:52 AM   #12
kgb
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You could try the GT28RS but the GT30R would require a different flange (a T3 style flange) - that would give you access to something bigger like the GT35R
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Old 11-02-2005, 04:43 PM   #13
MY99 2.5GT
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It also may require you to have the turbo custom clocked.
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Old 11-02-2005, 08:05 PM   #14
powerlabs
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Quote:
Originally Posted by Master2192
Upgraded Radiator (The RS radiators are TOO small for alot of boost, atleast track runs anyway)
Is it really? I've been running around 340 HP daily on a JDM WRX motor for over 4 months now on the stock RS radiator and the coolant temperatures have never reached the midpoint on the gauge, regardless of how hard I run it.
Has anyone actually overheated an engine with the 2.5RS radiator?
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Old 11-03-2005, 03:01 AM   #15
tony_subaru
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Make sure you come talk to me on Saturday Just make sure you have a tranny lined up. That RS tranny won't last more than a week with that kind of power...
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Old 11-03-2005, 12:33 PM   #16
MY99 2.5GT
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Quote:
Originally Posted by powerlabs
Has anyone actually overheated an engine with the 2.5RS radiator?

Yes

Because of Head Gasket Failure
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Old 11-03-2005, 03:20 PM   #17
v_dubs37
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Is there any high performance head gaskets for the RS?
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Old 11-03-2005, 03:42 PM   #18
v_dubs37
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does the WRX Water pump bolt right up?
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Old 11-03-2005, 04:28 PM   #19
2.5 Blue Roo
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yeah it bolts right up, but the install involves taking off yur timing belt
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Old 11-03-2005, 05:41 PM   #20
powerlabs
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Quote:
Originally Posted by v_dubs37
Is there any high performance head gaskets for the RS?
Yes. Cometic makes them out of copper.
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Old 11-03-2005, 07:46 PM   #21
v_dubs37
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should the head gasket be a consideration for a turbo set on the 2.5?

Last edited by v_dubs37; 11-03-2005 at 07:46 PM. Reason: forgot the ? mark
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Old 11-03-2005, 11:24 PM   #22
powerlabs
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Quote:
Originally Posted by v_dubs37
should the head gasket be a consideration for a turbo set on the 2.5?

Considering that the EJ25 blows head gaskets in stock trim, my answer would most definitely have to be YES.
Plus, you could get a thicker head gasket, drop the compression a little bit and run somewhat safer (or somewhat higher boost )
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Old 11-04-2005, 07:36 AM   #23
darioc
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something to think about when they go! no need in replacing them before hand. with a good tune they will last anyways.
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Old 11-04-2005, 04:14 PM   #24
kgb
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I would say the stock radiator on the RS needs some work, esp if you run water-cooled turbo like mine (GT28R). I still remember on a late afternoon drive in the summer when I was on boost for most of a 25 minute trip and my coolant temp stayed well over 110C (that's over 212F at least), and the car wouldn't cool down for a long while. Scared me for a bit and I say never do that until I get the cooling addressed.
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Old 11-04-2005, 04:26 PM   #25
Master2192
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Quote:
Originally Posted by powerlabs
Is it really? I've been running around 340 HP daily on a JDM WRX motor for over 4 months now on the stock RS radiator and the coolant temperatures have never reached the midpoint on the gauge, regardless of how hard I run it.
Has anyone actually overheated an engine with the 2.5RS radiator?
Alittle late on my response. I'm not sure how hard you run it, but there are several counts of overheating at track days with RS-Ts. He said he wanted to track his car so an upgraded radiator is in order i think. Better safe than sorry.

The RS radiator is just on the verge of being too small, so thats why it only shows up at track days or long drives under boost like kgb said. I doubt on the street you can run your car hard long enough to get it to overheat, unless your running from the cops or something....
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