Welcome to the North American Subaru Impreza Owners Club Friday October 31, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 11-20-2002, 01:23 PM   #1
AK'S REX
Scooby Newbie
 
Member#: 12163
Join Date: Nov 2001
Location: West Palm, FL
Vehicle:
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
* Registered users of the site do not see these ads.
AK'S REX is offline   Reply With Quote
Old 11-20-2002, 01:56 PM   #2
jmott
Scooby Guru
 
Member#: 6713
Join Date: May 2001
Chapter/Region: TXIC
Location: Houston TX USA
Vehicle:
2007 Prius
brown

Default

cobb uses the unichip on their 2.5 lier 420 all wheel horsepower beat, so im sure the utec should suffice as well

=)
jmott is offline   Reply With Quote
Old 11-20-2002, 02:11 PM   #3
AK'S REX
Scooby Newbie
 
Member#: 12163
Join Date: Nov 2001
Location: West Palm, FL
Vehicle:
2002 WRX

Default

I figured a UTEC would hopefully work. Now I just need to know about the motor and my glass tranny.
AK'S REX is offline   Reply With Quote
Old 11-20-2002, 02:25 PM   #4
jmott
Scooby Guru
 
Member#: 6713
Join Date: May 2001
Chapter/Region: TXIC
Location: Houston TX USA
Vehicle:
2007 Prius
brown

Default

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.
jmott is offline   Reply With Quote
Old 11-20-2002, 02:47 PM   #5
tolnep
Scooby Specialist
 
Member#: 18602
Join Date: May 2002
Location: Planet tolnep
Vehicle:
2005 Moller Skycar
glow in dark purple

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?
tolnep is offline   Reply With Quote
Old 11-20-2002, 03:19 PM   #6
AK'S REX
Scooby Newbie
 
Member#: 12163
Join Date: Nov 2001
Location: West Palm, FL
Vehicle:
2002 WRX

Default

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.
AK'S REX is offline   Reply With Quote
Old 11-20-2002, 04:46 PM   #7
WizardBlackWRX
Scooby Specialist
 
Member#: 14979
Join Date: Feb 2002
Location: Columbus, OH
Vehicle:
2002 WRX
Black

Default

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.
WizardBlackWRX is offline   Reply With Quote
Old 11-20-2002, 04:57 PM   #8
AK'S REX
Scooby Newbie
 
Member#: 12163
Join Date: Nov 2001
Location: West Palm, FL
Vehicle:
2002 WRX

Default

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.
AK'S REX is offline   Reply With Quote
Old 11-20-2002, 06:33 PM   #9
silverscooby
Scooby Specialist
 
Member#: 15060
Join Date: Feb 2002
Location: NC
Default

You might want to ask Nathan at turbo xs. He is running a 2.5 block on his badass car.
silverscooby is offline   Reply With Quote
Old 11-21-2002, 02:12 AM   #10
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

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
HndaTch627 is offline   Reply With Quote
Old 11-22-2002, 06:47 AM   #11
Avedis
Scooby Specialist
 
Member#: 8171
Join Date: Jul 2001
Chapter/Region: NWIC
Location: Mountlake Terrace
Vehicle:
2005 WRX STi
Blue / Gold

Default

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
Avedis is offline   Reply With Quote
Old 11-22-2002, 12:28 PM   #12
yebokmj
Scooby Specialist
 
Member#: 2213
Join Date: Aug 2000
Chapter/Region: South East
Location: Raymond, NH USA
Vehicle:
1995 Impreza w/EJ257
Brilliant Red

Default Aftermarket forum

Have you tried the aftermarket forum? Try a search of it or a post.
Joshua
yebokmj is offline   Reply With Quote
Old 11-22-2002, 01:29 PM   #13
Trey
Scooby Newbie
 
Member#: 670
Join Date: Dec 1999
Chapter/Region: TXIC
Location: Austin, the Republic of Texas
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
Trey is offline   Reply With Quote
Old 11-22-2002, 06:01 PM   #14
WizardBlackWRX
Scooby Specialist
 
Member#: 14979
Join Date: Feb 2002
Location: Columbus, OH
Vehicle:
2002 WRX
Black

Default

Indeed, but will you supply a closed deck with oil squirters only?
WizardBlackWRX is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
doing the 2.5 shortblock w/ 2.0 heads n8t_dog Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 5 03-03-2008 08:37 PM
Clearance and moving sale: forged 2.5 shortblocks, forged 2.0 shortblocks, and more Gruppe-S Engine/Power/Exhaust 14 06-20-2007 05:23 AM
Anyone see a 2.5 shortblock with 2.0 heads and TD04 or similar? AcquaCow Built Motor Discussion 27 02-08-2007 01:42 PM
wtb 2.5 shortblock & 2.2 heads kylemcspecial RMIC Private Classifieds 0 06-20-2006 01:59 PM
STI 2.5 shortblock bolted into 02 WRX with 2.0 heads Worth it? Davenow Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 12-24-2003 11:00 AM


All times are GMT -4. The time now is 06:58 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.