Welcome to the North American Subaru Impreza Owners Club Sunday December 4, 2016
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L 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. 
Closed Thread
 
Thread Tools Display Modes
Old 11-20-2003, 09:41 PM   #51
ANZAC_1915
Moderator
 
Member#: 456
Join Date: Oct 1999
Chapter/Region: NWIC
Location: Redmond, WA, USA
Vehicle:
2008 Forester XT
Steel Gray Metallic

Default

Dave, the last time I was home (Queensland) there was a lot of talk about the 2.5 STi being sold in Australia during 2004. Any news on that?
* Registered users of the site do not see these ads.
ANZAC_1915 is offline  
Sponsored Links
* Registered users of the site do not see these ads.
Old 11-20-2003, 11:40 PM   #52
APS
Scooby Newbie
 
Member#: 6894
Join Date: May 2001
Location: Melbourne, VIC, Australia
Default

Quote:
Dave, the last time I was home (Queensland) there was a lot of talk about the 2.5 STi being sold in Australia during 2004. Any news on that?
2.5 litre STi in Australia – no believable information at this time.

Further to the 2.5 litre short “mass produced” – the original context of this comment was explanation of the price difference of the different markets’ new vehicles. However, perhaps of more interest to everyone here; one can and we have, made over 600 hp flywheel on correctly clearanced 2 litre V7/8 shorts, in road racing applications. One would not keep a 2.5 litre US Spec short together in the same application, within 100 hp of that number.

Simple. You get what you pay for. Nothing new in that concept (applies to a lot of aftermarket product, also! ).

Dave, APS
APS is offline  
Old 11-20-2003, 11:43 PM   #53
Mudguts
Scooby Newbie
 
Member#: 46409
Join Date: Oct 2003
Location: Toronto, Canada
Vehicle:
04 STI
Blue/Gold

Default Hypereutectic vs Forged info.

FYI:
here is an interesting comparison (light reading) from a manufacturer of Hypereutectic pistons. See: http://www.beckracing.com/page11.htm

Beck Racing make some stong arguments for Hypereutectic Vs. Forged. PR or the evolution of piston technology?

Thanks,
MG
Mudguts is offline  
Old 11-20-2003, 11:54 PM   #54
strangerq
Scooby Specialist
 
Member#: 13095
Join Date: Dec 2001
Default

Quote:
Originally posted by APS
One would not keep a 2.5 litre US Spec short together in the same application, within 100 hp of that number.

Dave, APS

So does that mean your 468 hp USDM STI engine is nearly tapped out?
strangerq is offline  
Old 11-21-2003, 12:58 AM   #55
APS
Scooby Newbie
 
Member#: 6894
Join Date: May 2001
Location: Melbourne, VIC, Australia
Default

MG – PR!! – cheaper is the point!

StrangerQ– tapped out? In what context? A road race engine? Oh, we are well beyond that point! – i.e. 500 hp.

However, we are also well aware that most Americans assess durability in 10-12 second straight line bursts, not on a road race circuit. What will live for years in the former may well fail in two laps of the latter.

So, “tapped out” is too general, sorry.

Dave, APS.
APS is offline  
Old 11-21-2003, 01:42 AM   #56
blinguskahn
Scooby Specialist
 
Member#: 39301
Join Date: Jul 2003
Chapter/Region: BAIC
Location: The Haystack
Vehicle:
STi 05 8cm FPRed
WRX 06 Blue FP20G

Default

After reading these posts there is one thing that I think everyone so far has missed:

The brochure states that the pistons are forged. Since they are not forged, I'd like to demand some compensation form subaru. Look at recent dealings with Mazda and the RX-8. Subaru should offer current owners either a buy-back, free extened warranty, and cash back.

This kind of false advertising is really beginning to piss me off. I am going to call Suabru tomorrow and demand one of the three options be extended to all of us with these crappy motors.
blinguskahn is offline  
Old 11-21-2003, 02:51 AM   #57
hatchy
Scooby Specialist
 
Member#: 36852
Join Date: May 2003
Location: North West
Vehicle:
2004 STI

Default

So our mass produced pistons are "cheap" and "not as strong" as the "race" inspired forged pistons found in the "real" STIs... but no one can show me an example of a 2.5L piston letting go?
hatchy is offline  
Old 11-21-2003, 03:37 AM   #58
ANZAC_1915
Moderator
 
Member#: 456
Join Date: Oct 1999
Chapter/Region: NWIC
Location: Redmond, WA, USA
Vehicle:
2008 Forester XT
Steel Gray Metallic

Default

Quote:
Originally posted by blinguskahn
After reading these posts there is one thing that I think everyone so far has missed:

The brochure states that the pistons are forged.

...

This kind of false advertising is really beginning to piss me off. I am going to call Suabru tomorrow and demand one of the three options be extended to all of us with these crappy motors.
Which brochure, which page?

Yeah, I guess the motors are crap. They're dropping like flies.
ANZAC_1915 is offline  
Old 11-21-2003, 04:48 AM   #59
totoherbs
Scooby Guru
 
Member#: 7321
Join Date: Jun 2001
Chapter/Region: NESIC
Location: waltham, ma
Vehicle:
.... 122 IggPoints
Work... ahhh... so tired.

Default

Quote:
Originally posted by blinguskahn
After reading these posts there is one thing that I think everyone so far has missed:

The brochure states that the pistons are forged. Since they are not forged, I'd like to demand some compensation form subaru. Look at recent dealings with Mazda and the RX-8. Subaru should offer current owners either a buy-back, free extened warranty, and cash back.

This kind of false advertising is really beginning to piss me off. I am going to call Suabru tomorrow and demand one of the three options be extended to all of us with these crappy motors.

Not in any brochure I have read.... There are auto reporters say this but they have no offical word from subaru. So the rx-8 comparison is nul.

Quote:
Originally posted by hatchy
So our mass produced pistons are "cheap" and "not as strong" as the "race" inspired forged pistons found in the "real" STIs... but no one can show me an example of a 2.5L piston letting go?
Well ver8 uses cast, so....

And ya the pistons arnt as strong as forged but its not like there made of paper. So clam down.
totoherbs is offline  
Old 11-21-2003, 09:39 AM   #60
strangerq
Scooby Specialist
 
Member#: 13095
Join Date: Dec 2001
Default

Quote:
Originally posted by APS
MG – PR!! – cheaper is the point!

StrangerQ– tapped out? In what context? A road race engine? Oh, we are well beyond that point! – i.e. 500 hp.So, “tapped out” is too general, sorry.

Dave, APS.

Well it's your modded engine so if the question is general you provide the specifics. You're saying if you road race and APS modded USDM STI......the engine would blow? The pistons would melt? And what's the big deal about a road race in terms of engine stress......road race is every bit as general and could mean anything as well in terms of degree of stress. (one lap of america, a street race, pikes peak)

If what you are saying is true then you should be able to put the engine on a dyno and document the stress level's reaching some unacceptible point (temp, detting).

Sorry Dave, you can't blow the question off as being general just because you don't want to give a frank answer....or provide any real proof.
strangerq is offline  
Old 11-21-2003, 09:42 AM   #61
roybfr
Scooby Specialist
 
Member#: 14456
Join Date: Jan 2002
Chapter/Region: MWSOC
Location: WDM Iowa
Vehicle:
09 BMW 335i Sedan
69/72/01 Corvettes

Default

Rallispec is not selling USDM STi or WRX pistons that you CAN order from a dealer they are selling JDM Ver 3 thru 8 pistons that you CAN'T order though a dealer and must be imported. I just wanted to make that clarification. And please Dave if you think that $1022 is to much for a set of JDM forged pistons you should see what some people charge for a Turbo, talk about over priced

Last edited by roybfr; 11-21-2003 at 09:51 AM.
roybfr is offline  
Old 11-21-2003, 10:46 AM   #62
dwx
Scooby Guru
 
Member#: 8343
Join Date: Jul 2001
Chapter/Region: MWSOC
Location: Atlanta, GA
Vehicle:
2005 2012 Jeep
2013 DGM BRZ

Default

My whole point is the forged pistons aren't that much more than the cast ones. If you order STI pistons from SOJ right now, you will get cast pistons. The reasoning I've heard behind them switching to cast from forged was heat problems and the expansion of the pistons with tight clearances having piston rock problems and in some cases catching the cylinder wall. This was specifically in GroupN rally conditions, not drag racing. And not in cars that are 500hp.

The price thing is completely stupid, like they are specifically going to switch to a part that in quantity costs $10 less per car, and then throw in the DCCD transmission which is not available anywhere else but Japan mind you, which costs a helluva alot more than the standard 6MT. The wheel sensors, DCCD computer, dash cluster, switch, etc. would more than make up the price of that forged versus cast pison. And also put wheels on the car that cost an order of magnitude more than the ones found on the Aus car or any other international spec STI?

You are kidding yourself if you don't think the STI engines are mass produced.
dwx is offline  
Old 11-21-2003, 11:51 AM   #63
ANZAC_1915
Moderator
 
Member#: 456
Join Date: Oct 1999
Chapter/Region: NWIC
Location: Redmond, WA, USA
Vehicle:
2008 Forester XT
Steel Gray Metallic

Default

Quote:
The wheel sensors
For the record the TCU uses the ABS sensors.

Glenn
ANZAC_1915 is offline  
Old 11-21-2003, 01:42 PM   #64
n2xlr8n
Scooby Specialist
 
Member#: 18960
Join Date: May 2002
Chapter/Region: South East
Location: Bama
Vehicle:
02 WRX MBP
It lives! ; )

Default

"IMHO The one thing I do notice about the USDM STI piston is its smaller thickness from the top of the piston to the first ring land. This alone says its not as strong."


That would be known as compression height...it has nothing to do with strength. The reason there is a difference between the two in that regard relates to stroke and rod length.

.0015"........hmmmm. Noted.


Steve
n2xlr8n is offline  
Old 11-21-2003, 02:06 PM   #65
Daytona
Scooby Newbie
 
Member#: 39468
Join Date: Jul 2003
Chapter/Region: TXIC
Location: Houston
Vehicle:
2004 STi
Blue/Silver

Default

I am seeing a major difference in the pic APS shows and the other ones coming out of STi's USDM. APS's pic has a point in the middle, maybe this is the forester's piston that they got for $80?

I am not clear on the fuss about the RX8, haven't been following that one, could u post a link?

About the high-silicon content of the cast pistons, for those of you who ever raced Moto-X, the Nigu-sil pistons were all the rage in aftermarket 2-stroke motors, years ago. High silicon content is a great thing to have, as is a coating, whether a micro-film of ceramic or molybdenum...
Daytona is offline  
Old 11-21-2003, 02:09 PM   #66
totoherbs
Scooby Guru
 
Member#: 7321
Join Date: Jun 2001
Chapter/Region: NESIC
Location: waltham, ma
Vehicle:
.... 122 IggPoints
Work... ahhh... so tired.

Default

Quote:
Originally posted by Daytona
I am seeing a major difference in the pic APS shows and the other ones coming out of STi's USDM. APS's pic has a point in the middle, maybe this is the forester's piston that they got for $80?

I am not clear on the fuss about the RX8, haven't been following that one, could u post a link?

About the high-silicon content of the cast pistons, for those of you who ever raced Moto-X, the Nigu-sil pistons were all the rage in aftermarket 2-stroke motors, years ago. High silicon content is a great thing to have, as is a coating, whether a micro-film of ceramic or molybdenum...
Forester and the sti have the same piston, the rod is the only piece with a different part number between the 2 blocks. But it may be the same part too.

rx-8 doesnt make the power mazda said it did.
totoherbs is offline  
Old 11-21-2003, 02:14 PM   #67
Daytona
Scooby Newbie
 
Member#: 39468
Join Date: Jul 2003
Chapter/Region: TXIC
Location: Houston
Vehicle:
2004 STi
Blue/Silver

Default

This is what aps bought for $80
Attached Images
File Type: jpg us_piston1.jpg (10.6 KB, 284 views)
Daytona is offline  
Old 11-21-2003, 02:15 PM   #68
Daytona
Scooby Newbie
 
Member#: 39468
Join Date: Jul 2003
Chapter/Region: TXIC
Location: Houston
Vehicle:
2004 STi
Blue/Silver

Default

This is the USDM piston/con rod
Attached Images
File Type: jpg p1.jpg (4.2 KB, 286 views)
Daytona is offline  
Old 11-21-2003, 02:21 PM   #69
totoherbs
Scooby Guru
 
Member#: 7321
Join Date: Jun 2001
Chapter/Region: NESIC
Location: waltham, ma
Vehicle:
.... 122 IggPoints
Work... ahhh... so tired.

Default

Quote:
Originally posted by Daytona
This is the USDM piston/con rod
That is not the usdm piston.... the first one is. That is a jdm piston.




http://www.i-speed.us/news/sti_parts.shtml

The two pistons on rallispecs page are the forged ver7 and the cast ver8s.
totoherbs is offline  
Old 11-21-2003, 02:44 PM   #70
strangerq
Scooby Specialist
 
Member#: 13095
Join Date: Dec 2001
Default

Quote:
Originally posted by Daytona
I am not clear on the fuss about the RX8, haven't been following that one, could u post a link?

RX8 doesn't make the advertised horsepower. A real issue vs. an ahem.....non-issue in this case.
strangerq is offline  
Old 11-21-2003, 02:52 PM   #71
Daytona
Scooby Newbie
 
Member#: 39468
Join Date: Jul 2003
Chapter/Region: TXIC
Location: Houston
Vehicle:
2004 STi
Blue/Silver

Default

agreed, as long as my car makes lots of hp and torque, I am perfectly happy with a 'crappy' cast piston that doesn't eat the cylinder walls, clank around as much, etc. I did not buy a drag-racer from Subaru, I bought an amazingly capable vehicle that I can drive daily, have a warranty on, get good mileage in and put alot of miles on. I know some people have products to sell, and others feel cheated b/c they didn't get a WRC car off the showroom. Me, I'll most likely not heavily modify my car, just a reflashed ECU, a downpipe if someone can cure boost-creep, drop-in filter and that resonator remover plastic doohiky. No NOS, no track use. sorry
Daytona is offline  
Old 11-21-2003, 04:55 PM   #72
ToddStratton
Scooby Specialist
 
Member#: 8351
Join Date: Jul 2001
Location: Alabama
Vehicle:
2002 WRX Wagon

Default

Quote:
Originally posted by APS

However, perhaps of more interest to everyone here; one can and we have, made over 600 hp flywheel on correctly clearanced 2 litre V7/8 shorts, in road racing applications. One would not keep a 2.5 litre US Spec short together in the same application, within 100 hp of that number.
Dave, I think the problem a lot of people have in this thread is you have offered no quantitative proof for this and other statements regarding your perceived "quality" of the 2.5l block. For example, until you have tested, to failure, a large sample of the new JDM/USDM STi cast pistons, you're just making assumptions.

Quote:
Originally posted by APS

Simple. You get what you pay for. Nothing new in that concept (applies to a lot of aftermarket product, also! ).

Dave, APS
Do you really want a list of everything that your more expensive STi doesn't have that the "cheaper" JDM and USDM ones do have? STi decided that the new cast pistons are good enough for their best performance-oriented cars...hmmm.

It is interesting that what could have been useful information from you degraded into the "mass produced, weak piston" theme you keep talking about.

Why not mention the improvements made to the short block in other areas? Areas that may address the big-end problems seen overseas in previous STis.

TRS
ToddStratton is offline  
Old 11-21-2003, 07:55 PM   #73
tolnep
Scooby Specialist
 
Member#: 18602
Join Date: May 2002
Location: Planet tolnep
Vehicle:
2005 Moller Skycar
glow in dark purple

Default To APS, others, secrets of the Subie block

I wish, I wish.. some of the true experts, and I have no idea who they are would address technically, why one engine, or block or piston or piston and rod or piston and sleeved cyclinders is better.. What is better about the 2.0 block. What have you done to it that makes it better, what can be done to make it stronger... In the last several months, the discussion has become centered around pistons and piston slap and what it does to the block...

As a sort of aside. And I have no idea if what I am about to relate is BS or truth. But I was reading in a mag about a company putting darton sleeves in Honda b16-b18 block.. ERL Superdeck block I think. What is interesting is that they like to use 'seasoned' blocks to start because the blocks tend to oval and also the main bearings get out of align. So part of their process is to somehow realign the main bearings and press in the sleeves. What I found interesting was the discussion of what high HP mods did to these blocks (ovalling and bearing misalignment. Also there was a discussion about what different thicknesses of sleeves did to expansion and to cooling within the sleeved cylinder. Things that caught my attention were the ovaling, main bearing warping (not the best way to describe it but the bearing area became miss-aligned) and techniques used to strengthen a aluminum block. I wonder if any of the APS guys or anyone else would care to comment on what is needed to modify this block so it is 'better' than the STI 2.5. I don't doubt that there are secrets out their and I for one would like to know more....

At one time, I was going to mod up one of these things for my WRX or get an STI and mod it up. But I'm older and I want it to be dependable when I'm done. Increasingly I am beginning to believe that no matter what you do, beyond 350, maybe 400+ HP this block isn't strong enough to last. It gets 'ovaled' or the main bearings go for some reason or the pistons attack the cylinder walls or det bangs the bearings, piston skirt and the motor becomes a 'cropper'....
tolnep is offline  
Old 11-21-2003, 08:09 PM   #74
singletrack
Scooby Specialist
 
Member#: 42440
Join Date: Aug 2003
Location: Pittsburgh, PA
Vehicle:
04 Impreza WRX STi
Platinum Silver

Default

Quote:
Originally posted by blinguskahn
After reading these posts there is one thing that I think everyone so far has missed:

The brochure states that the pistons are forged. Since they are not forged, I'd like to demand some compensation form subaru. Look at recent dealings with Mazda and the RX-8. Subaru should offer current owners either a buy-back, free extened warranty, and cash back.

This kind of false advertising is really beginning to piss me off. I am going to call Suabru tomorrow and demand one of the three options be extended to all of us with these crappy motors.
BWAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA...stop, you're killing me.

-st
singletrack is offline  
Old 11-21-2003, 08:09 PM   #75
totoherbs
Scooby Guru
 
Member#: 7321
Join Date: Jun 2001
Chapter/Region: NESIC
Location: waltham, ma
Vehicle:
.... 122 IggPoints
Work... ahhh... so tired.

Default Re: To APS, others, secrets of the Subie block

Quote:
Originally posted by tolnep
I wish, I wish.. some of the true experts, and I have no idea who they are would address technically, why one engine, or block or piston or piston and rod or piston and sleeved cyclinders is better.. What is better about the 2.0 block. What have you done to it that makes it better, what can be done to make it stronger... In the last several months, the discussion has become centered around pistons and piston slap and what it does to the block...

As a sort of aside. And I have no idea if what I am about to relate is BS or truth. But I was reading in a mag about a company putting darton sleeves in Honda b16-b18 block.. ERL Superdeck block I think. What is interesting is that they like to use 'seasoned' blocks to start because the blocks tend to oval and also the main bearings get out of align. So part of their process is to somehow realign the main bearings and press in the sleeves. What I found interesting was the discussion of what high HP mods did to these blocks (ovalling and bearing misalignment. Also there was a discussion about what different thicknesses of sleeves did to expansion and to cooling within the sleeved cylinder. Things that caught my attention were the ovaling, main bearing warping (not the best way to describe it but the bearing area became miss-aligned) and techniques used to strengthen a aluminum block. I wonder if any of the APS guys or anyone else would care to comment on what is needed to modify this block so it is 'better' than the STI 2.5. I don't doubt that there are secrets out their and I for one would like to know more....

At one time, I was going to mod up one of these things for my WRX or get an STI and mod it up. But I'm older and I want it to be dependable when I'm done. Increasingly I am beginning to believe that no matter what you do, beyond 350, maybe 400+ HP this block isn't strong enough to last. It gets 'ovaled' or the main bearings go for some reason or the pistons attack the cylinder walls or det bangs the bearings, piston skirt and the motor becomes a 'cropper'....
Have you taken a look at the axis, ispeed, cobb, txs' builder(forget the name) motors.... ?they will be more reilable at the higher powers and wont oval.

As for the 2.0 vs 2.5, I personally think it comes down to what you like, lots of torque or a high reving motor.
totoherbs is offline  
Closed Thread

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
FS: 2.5L STi Block with CP Forged Pistons Suby_06_STI RMIC Private Classifieds 9 03-23-2009 01:32 PM
Version 8 turbo kit, 2.5L CP pistons, sti block, wrx heads jermany755 Engine/Power/Exhaust 8 09-26-2008 01:54 PM
a realistic compression for 07 sti 2.5L FORGED PISTONS jhook Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 1 08-04-2008 09:58 AM
FS: Rays Engineering Volks TE37 White , ej207 shortblock, 2.5L sti pistons, kvr rotor GC8_SpecC VIC Private Classifieds 3 09-11-2007 02:42 AM
FS: 4 2.5l Sti pistons Turbo4me North West Impreza Club Forum -- NWIC 8 09-16-2004 07:28 PM

All times are GMT -4. The time now is 01:48 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2016 Axivo Inc.
Copyright ©1999 - 2016, North American Subaru Impreza Owners Club, Inc.