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Old 11-20-2002, 01:23 PM   #1
AK'S REX
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2002 WRX

Default 2.5 shortblock w/ 2.0 head?'s

2.5 RS block
Forged JE pistons
Pauter Rods
Shaved (lightened/knife edged) crank
bored and honed
balanced
o-ringed for headgasket

What else will I need figuring I've got a toasted 2002 EJ20
I figure I can use the head and manifolds and turbo and all plumbing etc. What else if anything will i need? This should bolt up to my stock WRX tranny right?? What would be recommended for engine management. Would a UTEC suffice, or would i need something more standalone?
Any help or advice would be greatly appreciated. I need to do this quick as I've got a real expensive lawn ornament in my driveway right now

Thanks much,
-Adam
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Old 11-20-2002, 01:56 PM   #2
jmott
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cobb uses the unichip on their 2.5 lier 420 all wheel horsepower beat, so im sure the utec should suffice as well

=)
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Old 11-20-2002, 02:11 PM   #3
AK'S REX
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I figured a UTEC would hopefully work. Now I just need to know about the motor and my glass tranny.
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Old 11-20-2002, 02:25 PM   #4
jmott
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Quote:
Originally posted by AK'S REX
I figured a UTEC would hopefully work. Now I just need to know about the motor and my glass tranny.
I apologize for sounding like a broken record, but that same 420hp WRX runs the stock tranny. I hear it can smoke all 4 HUGE race tires coming out of corners too =)

Im sure some gentle care is in order though, and it probably won't last forever.
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Old 11-20-2002, 02:47 PM   #5
tolnep
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Default Re: 2.5 shortblock w/ 2.0 head?'s

Quote:
Originally posted by AK'S REX
2.5 RS block
Forged JE pistons
Pauter Rods
Shaved (lightened/knife edged) crank
bored and honed
balanced
o-ringed for headgasket

What else will I need figuring I've got a toasted 2002 EJ20
I figure I can use the head and manifolds and turbo and all plumbing etc. What else if anything will i need? This should bolt up to my stock WRX tranny right?? What would be recommended for engine management. Would a UTEC suffice, or would i need something more standalone?
Any help or advice would be greatly appreciated. I need to do this quick as I've got a real expensive lawn ornament in my driveway right now

Thanks much,
-Adam
I'm curious.. Supposedly the best pieced together Subie block is the ej22 (liberty?) block, the 2.5 crank. Seems like I heard there are problems with the 2.5 block if you turboing it (not strong enough). Is this a special or modified 2.5?
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Old 11-20-2002, 03:19 PM   #6
AK'S REX
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I was under the impression that the 2.5 internals and not the block were the weak point, and could not really take anything above 8 or 9 psi. Other than the above mentioned internals and machine work, the block is stock i think. I though i heard that Nathan @turboxs was running a 2.5 block, not sure to what extent though, for whatever that is worth.
I'm just thinking that this may be a decently reliable setup up to about 20 psi or so, and should yield some nice torque figures. Any insight or advice would be greatly appreciated.
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Old 11-20-2002, 04:46 PM   #7
WizardBlackWRX
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The first problem with the 2.5 block is the high compression. That is why you can only run lower boost; it will knock otherwise. Forged lower compression internals will fix that. The next thing to go is the open deck design. That is the real issue. I don't think many ppl really know at what range it will start to leak. You can brace it; that is what makes the 2.5 (with a few other things) a monster. Cobb does just those things, but they won't piece it together for you or tell you what they're doind. IMHO, sounds like they are ripping ppl off and trying to keep it quiet. I personally think they are.
The best setup, IMHO, is an STi V7 block with 2.5 crank and custom rods/pistons. It should be 2.15L, semi-closed deck with thick cylinder walls, etc.
The liberty block is great but the newer blocks are better designed, so I have been told. I haven't begun playing with the engine yet. I have a 2.5 phase 2 at the shop. I'm going to see what forged internals will do and how long the open deck can hang on.
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Old 11-20-2002, 04:57 PM   #8
AK'S REX
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So if i brace the open deck, i should be in business with the above mentioned parts? Figuring lower CR internals like u said.
I would like a V7 STI, but thats definitely out of my price range at this point. Wizard WRX, let me know what you come up with on your phase 2, thats essentially the same thing im looking at.
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Old 11-20-2002, 06:33 PM   #9
silverscooby
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You might want to ask Nathan at turbo xs. He is running a 2.5 block on his badass car.
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Old 11-21-2002, 02:12 AM   #10
HndaTch627
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the 2.5 itself is NOT weak, the piston ring lands are. Any detonation on them burns the ring land off like it's nothing. With forged internals and a proplerly built block you'll be fine.

jeremy
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Old 11-22-2002, 06:47 AM   #11
Avedis
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Some good info in here --> http://forums.nasioc.com/forums/show...hreadid=275816
Quote:
cost of 2.35L

ej22 block $1200-$1400
ej25 crank $200-$400
pistons $600-$1000
rods $600-$1000
o-ring block $200
head studs $200
gaskets $200
engine assembly $200-600

complete cost $3400-5400
...and more potentially useful info besides.

You might give Cobb a call, and see what they can offer you.

--jeff
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Old 11-22-2002, 12:28 PM   #12
yebokmj
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Default Aftermarket forum

Have you tried the aftermarket forum? Try a search of it or a post.
Joshua
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Old 11-22-2002, 01:29 PM   #13
Trey
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Default

Quote:
Cobb does just those things, but they won't piece it together for you or tell you what they're doind. IMHO, sounds like they are ripping ppl off and trying to keep it quiet. I personally think they are.
Our 2003 Pricelist and new web site (coming soon) will allow individual engine items to be purchased instead of only complete engine builds. We're also going to change the engine build stages to allow people to order either the individual parts or complete engines built to their tastes. Want a 2.5L block but only semi-closed with forged pistons, billet rods and a piston cooling oil system? Then you can order just that (and yes, I said piston cooling on a Phase 2 block).

As for releasing information, I'm working on some indepth technical articles on Subaru engine builds that will explain what and why we do things, the combination of parts you can use, compatibility, etc. Hopefully that'll help some of you in your quest for the ultimate engine build.

Last year we focused heavily on increasing the amount of racing programs we were involved in, in an effort to both improve our products and generate the capital needed to invest in development programs. As a result, our engines won several national and international races including the 2002 SCCA Pro Rally Overall Championship -- besting even Prodrive-Subaru and the other factory backed teams. We made over 100 design changes to engine parts as a result to what we learned in professional level.

The primary goal with our engine program is to provide the best quality and most technically advanced parts available in the market place. Unfortunately, that type of development costs money which the business has to generate somehow.

Best regards,
Trey Cobb.
www.cobbtuning.com
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Old 11-22-2002, 06:01 PM   #14
WizardBlackWRX
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Indeed, but will you supply a closed deck with oil squirters only?
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