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Old 02-20-2018, 11:50 AM   #1
Felman
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Member#: 471691
Join Date: Jul 2017
Chapter/Region: International
Location: Europe
Vehicle:
2006 Impreza STI
Blue 02c

Default Aftermarket cast pistons?? - not the oem -

Hi Guys, how is it going!!

I am proud owner of a Impreza WRX 2007 (hawkeye 2.5 turbo 230hp)

I am going to to try to be concise and direct to the topic.

We all know the 2.5 pistons failure problem. I read A LOT (probably all the internet ) and I know/learned how to care the drive, how to drive this engines (not full load under 3.000rpm, not hard launches after minutes stop, good oil etc etc etc to avoid the failure ... but I still live with that fear, because I saw more than one stock 2.5 Subaru Turbo EJ25 crack the pistons

Mi WRX is stock, and if someday I decide to tune it, I will tune it up to 260/280/300 hp MAX (I dont want more, really, I dont want more)

Here where I live (Spain, Europe) there isnt too much culture of Subarus/engine rebuild etc, and everybody I know from Subaru clubs, they say the only way to reliable the engine is to put forged pistons. The problem is, when you put forged pistons, you need to give some CTW, wait for engine warm, even with "medium" alloy (4032), their longevity is lower than cast pistons, etc... and its all a mess .... because my Subaru is daily use, and i want to use it for many many years and milleage

so.... we know the main problem is the stock piston weakness ... now, the question is: I WONDER if does exist an AFTERMARKET, good quality, CAST strong enough piston to replace the stock ones, and solve that problem without need to go forged, something that is designed for high levels of power/hp .... because I want to stay very near to stock power (260/280 hp)

Do you know any? do the exist? - or the onlys aftermarket pistons are all forged all of them?

thank you very much!!
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Old 02-20-2018, 11:57 AM   #2
lowbee
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Member#: 254317
Join Date: Aug 2010
Location: Toronto, Canada
Vehicle:
2011 STi

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subscribed ... I also want to avoid the hassle of having a forged piston if/when that time comes... so interested to learn what is available out there

Last edited by lowbee; 02-20-2018 at 12:27 PM.
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Old 02-20-2018, 12:06 PM   #3
redrex009
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Member#: 337456
Join Date: Nov 2012
Chapter/Region: NWIC
Location: tigard,oregon
Vehicle:
2009 wrx
lightning red

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After getting severe rod knock, I went with OEM STI shortblock with forged pistons. My only complaint is sometimes it sounds like its knocking especially in the morning. However I think I just have a little ptsd. That is not a fun experience....
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Old 02-22-2018, 01:33 AM   #4
pooster.online
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Join Date: Jul 2006
Chapter/Region: PRSIC
Location: Philippines
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Davi WRX STi JBP
DavidAgorsAJ

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sounds like youre looking for a 4032 alloy vs a 2068.
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Old 02-22-2018, 08:55 AM   #5
Samurai Jack
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Location: Not in my own time
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2002 Enemy of Aku

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Quote:
Originally Posted by pooster.online View Post
sounds like youre looking for a 4032 alloy vs a 2068.
You're confusing what you are saying.

Both piston types will knock on cold start.
The 2618 typically knocks more than the 4032 because 2618 expands more when it gets hot, so more PTW clearance is needed, as compared to 4032.
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Old 02-25-2018, 01:47 PM   #6
subaru_gc8
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Join Date: Nov 2002
Chapter/Region: SCIC
Location: Orange County CA
Vehicle:
2004 WRX wagon
silver

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maybe wait til the STI RA pistons come out on the market
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Old 03-31-2021, 04:20 PM   #7
rsdrew
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Old thread ... any updates ??
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