[Rootus]

Originally Posted by xerox445

I don't know for sure, but hasnt the 2.0 JDM STI block always had forged internals?

Nope. The EJ207 had forged pistons up through v7. Since that time Subaru switched over to hypereutectic.

I'm not sure why all the hate for cast pistons, anyway? It's not like forged pistons are magical. They break too if you have a bad tune. The biggest problem with the stock EJ257 pistons is thin ringlands, not the fact that they're cast. Even then, a number of people make an awful lot of power with competent tuning on stock STI engines.

[SNE2040]

Originally Posted by unclejemima

Are they any different material than the 07's?
-mark

Honestly, i'm not sure about the complete difference of the 06 Evo IX and the 08 Evo X. I know that they made the Evo X 5-Speed a LOT beefier to handle more torque, and rumors say that the Evo X motor will be able to handle high boost because of its new internals and motor design.

[snorky]

Originally Posted by SNE2040

Honestly, i'm not sure about the complete difference of the 06 Evo IX and the 08 Evo X. I know that they made the Evo X 5-Speed a LOT beefier to handle more torque, and rumors say that the Evo X motor will be able to handle high boost because of its new internals and motor design.

wrong forum bro

[modaddict]

"My 08 Sti runs rough, eats oil, and blows smoke just like the 04, 05, 06, 07"



drrrrr...I think you broke a piston.

[supermarkus]

Originally Posted by subaru_sti293

CHECK THIS SITE: 2008 Subaru Impreza WRX, STI specifications, options, prices, and photographs They never mention what kind of piston there using for in STI 08 , the same thing what happen in STI 07 they never given you a brochure coz they using Aluminum alloy pistons not forged piston its a part of subaru trick how they rip-off a lot of customer especially the Subaru dealership .


2007 WRX AND STi MECHANICAL AND STANDARD FEATURES
S = standard, 0=optional
subject to change, correction model WRX and TR
sedan WRX wagon Limited sedan, wagon STI, STI Limited sedan Engine 2.5L boxer DOHC, 4 cylinder, 16 valves
Active Valve System
Turbocharged
Hood scoop air intake with Intercooler
Block and heads, Aluminum alloy. open deck design, with
cast iron cylinder liners
Sequential multi-port fuel injection
Bore: 99.5x79mm, 3.92x3.11
Redline 7000 rpm

2.5L boxer DOHC 4cylinder, 16 valve
Turbocharged, high-boost, IHI Brand
Air-Intake Hood scoop with Water-Sprayed intercooler: manually operated hood-scoop water spray provides additional cooling to the intercooler, use distilled water, do not overfill if freezing is possible.
Drive-by-wire throttle
Aluminum alloy pistons
Cast iron cylinder liners
Reinforced "semi-closed deck" alloy block
Forged high-carbon steel connecting rods
Resin composite intake manifold
Electronic Drive by Wire throttle
Bore: 99.5 x 79mm, 3.92 x 3.11"
Redline 7000rpm
Tach to 9000rpm

so, umm... what part of a forged aluminum piston is not aluminum alloy? Good luck with your conspiracy theory.

[sponaugle]

Originally Posted by Flycaster

BTW, I just thought I'd add that all of this is "eyes-on" confirmed - Sponaugle tore his brand new motor apart just to have a look-see.

Indeed. I put in CP pistons while I was in there. The pistons are exactly the same as the 04,05,06, and 07 pistons. The rings are a new part number, but not sure what has changed. The rods are also new.

Originally Posted by xerox445

I don't know for sure, but hasnt the 2.0 JDM STI block always had forged internals?

I ran a Spec C V7 block for a while, and the pistons were a high silicon forged type, and were very strong.

Originally Posted by unclejemima

Are they any different material than the 07's?
-mark

No, and the 07s are the same as the 06, 05, and 04.

Originally Posted by Rootus

Nope. The EJ207 had forged pistons up through v7. Since that time Subaru switched over to hypereutectic.

I'm not sure why all the hate for cast pistons, anyway? It's not like forged pistons are magical. They break too if you have a bad tune. The biggest problem with the stock EJ257 pistons is thin ringlands, not the fact that they're cast. Even then, a number of people make an awful lot of power with competent tuning on stock STI engines.

Indeed the cast vs forged is not as significant as the alloy choice and design.

Jeff Sponaugle

[unclejemima]

Good post sponaugle...thanks. You cleared up alot for me.
-mark
PS
I know its not part of this forum, but does anyone know if the evoX is running forged pistons stock in US spec?

[unclejemima]

Originally Posted by unclejemima

PS
I know its not part of this forum, but does anyone know if the evoX is running forged pistons stock in US spec?

not that anyone will care, but what i can find for info, the 08 evo x DOES NOT have forged pistons either, just forged crank and forged connecting rods. The only reason i wanted to know, so i can sleep at night knowing my buddie with the EVO X doesnt get forged pistons either!
-mark

[brnsingh]

Originally Posted by Rootus

Nope. The EJ207 had forged pistons up through v7. Since that time Subaru switched over to hypereutectic.

I'm not sure why all the hate for cast pistons, anyway? It's not like forged pistons are magical. They break too if you have a bad tune. The biggest problem with the stock EJ257 pistons is thin ringlands, not the fact that they're cast. Even then, a number of people make an awful lot of power with competent tuning on stock STI engines.

I wish to concur , i have a JDM V7 does indeed have forged internals , from V8 onwards hypereutectic casts.Only benefit of forged allows higher boost and a bit more resistant to detonation , but will still blow on bad tune .

[bytor]

Originally Posted by Blip

Sometime people are never happy, think of it this way would you pay another 2-3 K extra for a STI with forged pistons. And before you say forged pistons only cost X you have to look at warranty and able to last. Do you know that most people in Japan do not keep there cars longer than 3 yrs and they do not put the same mileage on there cars as we do. How many motors do know with over 100K on the clock. I my self put a 125K on a highly tuned 01 S4 in 7 years. The Last 2 years that I had that car I only put 20K on it most of it was on the track or going to tracks so freeway. Car companies are in that line for work to make money. What if you paid the same money for an 08 STI and got the car with forged pistons, but at 75-100K mile you needed a new motor would you still buy it. So they detune a motor so that it last longer hell I can get a 1.2 liter V8 bi turbo that makes 1200 HP and around 1800 TQ that would last for about 200 KM and at the time cost around 500,000 US Dollars. Subaru does a great job of giving you a high HP car 122HP per liter in stock mode that you should be able to put a 100K miles on it with out a problem this is one reason I made the switch from Audi to the new STI.
People say the new STI/EVO cost to much will the next AWD car that would even come close is a S4 or S5 and they cost 55-60k. BTW the new 08 S4 is going to be a DI 3.4 Bi-turbo and it will have forged pistons and if Audi does it's normal thing you should be able to get about 188 HP per liter with mods so that would be around 600 HP or around 490 WHP. The engine will still be bullet proof, But it comes at a $$$$$$ the upgrades on the Engine I am guessing 8-9K.

Having broken a ring land and put two vertical cracks in a piston between the rings (along with a much more catastrophic failure) in less than 2k miles, I wouldn't mind the extra cost for forged pistons and if it won't void the warranty, may go that route. I have zero confidence in the stock pistons for the (admittedly extreme) way I use my car.

[upncummr]

Originally Posted by bytor

Having broken a ring land and put two vertical cracks in a piston between the rings (along with a much more catastrophic failure), I wouldn't mind the extra cost for forged pistons and if it won't void the warranty, may go that route. I have zero confidence in the stock pistons for the (admittedly extreme) way I use my car.

So add in the cost of forged pistons, engine removal and reconfiguration, engine re-installation and it's starting to sound like this could be expensive.

Gary

[mofoSTI]

I would pay extra for a package that would include better pistons and the recaro seats.

[inpuressa]

Originally Posted by bytor

Having broken a ring land and put two vertical cracks in a piston between the rings (along with a much more catastrophic failure) in less than 2k miles, I wouldn't mind the extra cost for forged pistons and if it won't void the warranty, may go that route. I have zero confidence in the stock pistons for the (admittedly extreme) way I use my car.

man, what did you do to the car? I was thinking stage two, but got a little concerned now.

[supermarkus]

Originally Posted by inpuressa

man, what did you do to the car? I was thinking stage two, but got a little concerned now.

You're kidding right? His thread is only one of the busiest threads in 08 discussion.