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Keep 205 or Buy STI engine

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Discussion Starter · #1 ·
I have an '04 WRX. I want to continue my build, but I want to start with internals. My current EJ205 has around 118k on original motor. Should I buy and install forged internals, or just buy the STI engine that comes w/ forged?
 

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The STI engines don't have forged pistons outside of the JDM that I'm aware of.

You'll likely find buying a built block from a company like IAG to be similar in price to building what you have.
 

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Discussion Starter · #3 ·
The STI engines don't have forged pistons outside of the JDM that I'm aware of.

You'll likely find buying a built block from a company like IAG to be similar in price to building what you have.
Oh ok. I was told they do. Should I invest in a new engine or replace the rods/pistons with forged?
 

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Are you aware that forged pistons will necessitate a rebuild more frequently?

All turbocharged EJ motors have forged rods and crank. The STI motor won't just drop-in. You will need a new ECU (or re-purpose an existing ECU channel) and new wiring harness to make it "work" with a 2L WRX. That's a lot of money to spend on a car that isn't worth terribly much.

If you REALLY want to spend the money on the car, the best solution IMO is the 2.1L stroker build. This involves using a 2L crankcase and a 2.5L crankshaft to increase the stroke from 75mm to 79mm. Paired with a good piston and rod combo and headwork, these motors have all the great characteristics of the 2L (willingness to rev) while spooling a turbocharger similar to the 2.5L. I wonder if anyone will do that build anymore? The 2.1L with Polyquad would have been my dream build for an older WRX.
 

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BooSTIng
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What is your end whp goal? That will tell you a lot on what type of build you need to do. I agree with zax though, upgrading to a 2.5l STi engine is more of a headache than what is worth. If your current engine isn't blown up, I would personally just have it pulled and rebuild rather than buying a whole new shortblock. But that is just my opinion. It will be much cheaper in the long run.
 
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