[Karlot]

@yamahaSHO may know better and correct me.

but i think you should be able to use an ej257 longblock without issue, not sure if there are any connections with wiring that change with that. i dont think there are, but i could be wrong. though, i wouldnt expect any increased reliability from that motor. the shortblock aka the weak point is still very close to the same as the 255 from the wrx. so far as the ecu/ecm, i dont think you'd need to change that, but i would go with a custom tune, yamaha is a tuner and can get you squared away there, the oem tune leaves alot to be desired.

while you are in there, i'd say a must is going to be the killer b oil pickup and baffle (pan is nice, but not needed unless youre tracking the car), and i'd get a quality AOS (IAG, Cobb aka rebranded IAG, or killer b).

if you are going for bigger power, i'd consider just getting an IAG shortblock, and rebuilding the oem heads, especially because with a IAG installer (which there are quite a few) you'll get a warranty on the built motor. though, your power goals and use for the car you may not want to spend the extra money on this. and a type ra shortblock may be a better option here.

 

[Karlot]

I found an ecm rebuilder that can clone the sti program and flash it into the wrx ecm to resolve the immobilizer issue.
That will make the sti avcs fully functional. The goal is to have the full 305 hp from the sti setup but also put forged rods, non forged racing pistons, heavy duty head studs and head gasket. "Racing" rod and crank bearings but keep the hp about the same, at least for now.
The sti engine only has 60k but some damaged internals which I'll repair/replace as needed.
To summarize, maximize hp as designed, reliability, longevity, but have the option to play with the boost and programming.

few things here. unless you have a machine shop, you are probably going to be MUCH better off buying an already built motor from IAG or picking up an oem subaru type RA shortblock. having damaged internals could lead to ALOT of things you can not see until you are in there. which will really drive up the cost. IAG offers built motors with warranties. rebuilding vs buying a new shortblock tends to be a very minimal cost difference, and because of that, it's more common to pickup a new motor based on your goals.

the sti does not have 305whp at the tire, on our local dyno, it was typically in the 240 ish whp range. and even if you are making 300whp, all the extras are not necessary for reliability, it's just extra money. a type ra block will hold 300whp all day long without an issue (provided you have a good protune, which, yamahasho a few posts up can help you with). also adding rods/pistons/bearings will not add any horsepower, unless you are changing the compression ratio, and even then, it wont add much.

going with which motor depends on the end goal. not the for the moment goal. if your end goal is 600whp, sure, go with a built motor. if it's 300s, an ra block may be a better option

 

[Karlot]

I've looked at the iag engines, once I get these 2 disassembled and inspected I'll make the decision. I've had bad luck with machine shops and specialty mechanics in general. It either takes them too long or the work isn't good for the cost.
Normally I do everything myself, then I'm certain nothing has been overlooked or done poorly.
Most of the time, the parts all measure and don't need machining.
I did head and cylinder work on a Mercedes Benz 300te years ago, the cylinder walls on that engine are designed to have near zero wear , up to one million miles... Anyway
I believe the culprit in these wrx turbos is likely incorrect octane causing much of it, although suburu is demanding alot by putting turbo chargers on them in the first place.

cant speak for other shops, but IAG does quality work. i personally have a built motor from them with like 50k miles on it, still going strong. idk lead times currently, so i cant speak to that.

but yeah, if you have a hurt motor, you'll want machine work, on the cylinders almost certainly, possibly the heads, depends on where the damage was/is

 

[Karlot]

what's the power goal if you want a new turbo (also 2300 is EXPENSIVE AF for a timing belt even with parts and labor)

also, the wrx trans will only hold so much power, if you upgrade the turbo, you will need to look into either building the trans or swapping in an STi 6 speed.

 

[Karlot]

Yea, 2300.00 is a lot, it was surprising when I got the bill.
I'm not looking for major power, it's quite powerful stock, only looking to liven it up a hair. Quicker response, less lag. Maybe 30 more hp.
I just ordered a Rebuild kit for the turbo....the bad seals explain the oil usage and smoke.
The cylinders, pistons and rings all looked good.
Will a Cobb tuner allow changes to the boost, timing and fuel delivery?
Thank you

you will not find anything with quicker response than the stock turbo.

i will say, if you are only wanting another 30whp, adding a downpipe and a tune will gain that. heck a tune with an otherwise stock car would probably come close to it. but if you wanted a turbo that spools fast, but holds the power up top, a blouch 18g xtr would spool SLIGHTLY later (probably enough that you wouldnt really notice, i'd guess only a few hundred rpm), and will carry power past that 5500-6k rpm mark where the stock turbo completely falls off. when you tune it the stock turbo can peak 21 psi but will fall off to roughly 15-17psi by redline. hence suggesting something that will carry the power higher into the rev range.

and yes, the cobb tuner will allow changes to boost/timing/fuel etc. i'd HIGHLY suggest a protune, which @yamahaSHO can help you with. he's a tuner who frequents the forum and can get you an accessport and a protune to go with it, which will be MILES better than one of the cobb OTS (off the shelf) maps.