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Discussion Starter #1
Well the car is in the shop and we are looking to figure out what the problem w/my boost is. It looks like I'm leaning towards a new block. Stock usdm Sti block. That will do for now...I wonder how much power I will make ?

How much stronger is that block vs. my stock 2.0 block ?

Is it expensive to replace the rods/pistons after the block is installed ?

How much boost do you think that can handle stock ? I'm looking to run 20-25 lbs depending on the gas?

What do you think ?
 

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It will allow you to make more power :)

It is slightly stronger.

You have to remove the engine again and break it down completely. Also, you would want to replace the main and rod bearings. So it is better to do it before you install it.

I wouldnt go higher than 25 psi.

-Mike
 

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13secwrx said:
Well the car is in the shop and we are looking to figure out what the problem w/my boost is. It looks like I'm leaning towards a new block. Stock usdm Sti block. That will do for now...I wonder how much power I will make ?

How much stronger is that block vs. my stock 2.0 block ?

Is it expensive to replace the rods/pistons after the block is installed ?

How much boost do you think that can handle stock ? I'm looking to run 20-25 lbs depending on the gas?

What do you think ?
I knew this day would come....the grim reaper of the engine netherworlds comes knocking at your door. Key points to notice on the STi block is that:

1. It's semi-closed deck (slightly stronger, but this arguement is BS unless you want to run 30+ lbs of boost since I have yet to hear of anyone busting open a cylinder wall)

2. It can't rev as high as a 2.0 liter would be able to with aftermarket valvetrain upgrades, but makes a lot more lowend torque and would definately pull harder in the 1/4 mile

3. Has forged rods but probably some of the worst pistons used in an STi or WRX to date (to quote a reputable engine builder who is earning lots of my money as we speak).

4. Would probably tire out your tiny little 18g running more than 20lbs of boost

5. This swap, assuming you use your stock wrx heads, would raise your compression ratio to 8.5:1 instead of the stock 8:1, making more power down low off boost, but slightly reducing your knock threshold and preventing you from using a lot of ignition advance under heavy load, making your high power tuning more finiky under heavy boost.

6. AZScoobie on Nasioc is using a completely stock USDM STi bottom end on his car with a garrett hybrid (I believe, correct me if I'm wrong) and can offer limitless knowledge when it comes to tuning this engine and has made a lot of very reliable/driveable power with AVCS STi heads from a v7 japanese car I believe.

7. Your fuel economy will be cut in half and you will hate it every time you fill up....literally, you'll get probably 15mpg on the highway under completely stoich afr's. Oh well...

8. If you want a fully forged/high power/balls to the wall engine with the STi block, balanced crankshaft, forged rods/pistons... do it now while the car is ripped apart, don't plan on doing it later because it will only cost you an extra $1500 in labor if you want to tear down your engine a second time after this initial fix.

9. Good luck, can't wait to whip your pansy @ss on the expressway service roads :D:D:D:D:wiggles::D:D:D:D
 

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i agree, if you are already set on the 2.5 block then it is a very good ideas to have the pistons/rods/ and even head work, etc. done before it goes in. that damned boxer is a pain in the a$$ when it comes to internal work. cam job on an evo is like 30min. subaru is more like 30 days...:(
as everyone said, usdm block you get a little more strength, but alot more torque down low!:)
 

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keep us posted on the status of the motor....if i remember correctly its was detuned alittle to be on the safe side right....when did you start felling the "lag" felling around 14 PSI....was it just one day after you started the car up or after a WOT run???

once again im sorry for your loss and i hope its nothing serious
 

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POLAR said:
i agree, if you are already set on the 2.5 block then it is a very good ideas to have the pistons/rods/ and even head work, etc. done before it goes in. that damned boxer is a pain in the a$$ when it comes to internal work. cam job on an evo is like 30min. subaru is more like 30 days...:(
as everyone said, usdm block you get a little more strength, but alot more torque down low!:)
Have you ever put cams in an EVO? Def not 30 minutes...
 

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Discussion Starter #8
Well my engine is out and the new one is being put in...I dont have enough $$$ right now to build it up, I only have enough to put the new engine in. Sucks I know...but well.

That gas milege thing sux but ah well...

I'm going to run a 22 lb map and a 17lb map right now at first. Then I will get my new gears and my bigger turbo and then go a little crazy...but for now it should make more power then what I had.

I'll keep you posted...should be ready in a week or so.

P.S: I'm ready for you tim...any time you are. 400 whp here I come.
 

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13secwrx said:
Well my engine is out and the new one is being put in...I dont have enough $$$ right now to build it up, I only have enough to put the new engine in. Sucks I know...but well.

That gas milege thing sux but ah well...

I'm going to run a 22 lb map and a 17lb map right now at first. Then I will get my new gears and my bigger turbo and then go a little crazy...but for now it should make more power then what I had.

I'll keep you posted...should be ready in a week or so.

P.S: I'm ready for you tim...any time you are. 400 whp here I come.
you have a sickness man......... seek help!!!

















every couple months you have a new *big* upgrade in your car... :rolleyes: :thumbup: :D



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After reading the usdm vs jdm STi swap it seems that the only way to go is to get a complete V7 motor and just throw that in...but then to control the avcs you need the jdm ecu...not worth it imho. Why not opt for the legacy 2.2? Its 1800ish and has a really strong bottom end and is the balance between the 2.0 and 2.5
 

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Well, my car went in today for the 18G etc. and I will have it on the road late next week. I think I am going to start saving now for a 2.5 block and gears......:(
 

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Worst pistons ever put in a Subaru motor(sti or wrx).... LOL thats funny. They might be worse than the forged sti pistons in the 2L when you are talking about detonation resistance. But, they are very very very strong pistons when it comes to holding power. None of the 2L motors in the stis have eclipsed the ej257 record for all boost horsepower that we know of. 504 or 510 with two STi's down in Puerto Rico. I wouldn't push it too much just so you arent the guinea pig and let the guys with more money push it. But, I would agree with Mike saying that 25 psi with a decent sized turbo should probably be a point where you start looking for stronger internals(pistons at least) because detonation is much more severe at higher loads than at lower loads(that being what kills our pistons). But, bear in mind that 30+ psi has been run through the stock block with a FP green turbo so its do-able. Good luck man and upgrade that turbo. They are SUPERCHEAP to upgrade through Deadbolt. Mine is off being Superzilla'd now. IM me on aim if you have any questions about it.

Richard
 

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MJU1983 said:
Have you ever put cams in an EVO? Def not 30 minutes...
sorry, i thought youd see the sarcasm in it when i mentioned the subaru took 30 days. just trying to make a contrast here.
but 13sec, i would def. go with the legacy 2.2. i use it, and its going to be much stronger, and will be able to run the high boost you need on a bigger turbo as opposed to the 2.5. either way, your set to make good power.:)
 

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Block has nothing to do with it. The dang 2.2L Leg motor is not so great under high boost(higher compression pistons, crap pistons, crap rods) Ok... well it does have squirters but thats the only good feature of that shortblock stock for stock. Now when you get into forged bottom end(which isnt needed for an 18g) all bets are off because no one has blown up either block at the walls or anything that we know of.

Richard
 

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Re: Re: 2.5 Block ????

Timdog1650 said:

7. Your fuel economy will be cut in half and you will hate it every time you fill up....literally, you'll get probably 15mpg on the highway under completely stoich afr's. Oh well...

expressway service roads :D:D:D:D:wiggles::D:D:D:D

I get 300 miles a tank and this is driving through Northern VA/DC suburbs so trust me this is not hwy driving by any means.
 
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