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Discussion Starter #1
What are the problems that I will run into putting a JDM drivetrain into a US RS or L model impreza? I am looking for performance and all kinds of power? What legal, smog, certification, and repair issues could I run into?

I am building for street/strip use, but would love to do some rallying.

Thanks
 

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not that i've done a conversion or anything, but i imagine that the parts (assuming they're from a GC8) should fit in directly. wiring will probably be a mess. you also will probably have to get creative with the steering rack location as well. the exhaust will obviously have to be completely reworked.

legal issues-none that i know of as long as it passes all the regular checks.

smog-good luck.

certification-assuming it passes emmissions and all that, i doubt very much that the tech is going to notice that its a JDM engine. besides, its not illegal to modify your car as long as it still meets all the saftey/emmissions crap.

repairs-well, obviously the warrenty is gone. also, if you damage something in the JDM parts, thats where the replacements will have to come from. replacements which you will have to order yourself more than likely. if this car is your only one, if something breaks you could be seriously hosed.

all that being said, there are a few other issues you might want to keep in mind. J-spec performance engines are designed to run on 100 octane gas (which they have at the pumps). the best you can get at most places in this country is 91-93. this means that your going to have to change the fuel/timing maps more than likely if you want to run standard US pump gas. i know here in st louis, the gas station across the street from the big oval carries 99 or something like that, but its ~$5/gallon. another issue is if you want to rally it, there are certain safety rules that you must comply with at the very least, such as a roll cage, underbody protection, a fuel cell (unless you gaurd the gas tank really well), driving suit/helmet, fire system, kill switch, etc. rally cars just don't make very good street cars ;)

anyway, i'm in no means trying to discourage you, just pointing out some things to help you make the right choice. good luck!
 

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If you insist on going JDM, get a front clip. You can buy a USDM WRX motor, crossmember, and wiring(everything needed for the conversion) for $4800 + shipping. This will actually pass smog, even in CA. Once you did this swap, you would have available to you every WRX upgrade. Even with everything stock, you would spank WRXs bad due to the 300 lb weight advantage. The next step would be building up your 2.5 block and dropping it in with a much bigger turbo. I am doing the "big block" swap for one of my WRX customers now.
Kevin
 

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Discussion Starter #4
scoobyrs25

I was looking at a twin turbo EJ20TT JDM rated at 280bhp, for sale on the internet. I am sure it would work but it would be a lot of work.

So give me more details on how to big block, or hop up a 2.5. From what I know, which I will admit is not much, you would have to rebuild the longblock with lower compression pistons so as to be able to do serious forced induction. That is anything in excess of 5psi.

Give me the skinny Kevin,

Anthony
 

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The Legacy twin turbo motor you speak of doesn't really fit in our cars. The steering and brake parts on our cars interfere with the driver's side turbo. For making a stout 2.5 block, you will need to replace the pistons with 8.5:1 forged units, and forged rods. Don't forget the hidden costs of new bearings and gaskets, these get quite pricey. While the motor is apart, you might as well knife edge the crank. This will help the motor rev more freely.
Kevin
 

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I wish it wasn't so damn expensive to ship a big container to the US or I'd send the two WRX's that are here locally to the US. Cause $4800 is alot of cash for something that you can get here for less then a grand.
 

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Discussion Starter #7
scoobyrs25

what are we talking about in terms of cost? while the heads are off what about doing some porting?, of is that not necessary. i assume from your other post that this it the type of work you can do.

thanks,

N/A

where are you that these are so common and fair priced? england, austrailia, etc?
 

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I am in Southern California, of course it can be done! Actually, I use the same head shop that does the heads for the US Subaru rally team. I am in the process of building what I spoke of right now for a customer of mine.
Kevin
www.pkZero.com
 

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[rant mode on]

Why does everybody want these damn Legacy B4 TT motors? It's like every time somebody clicks around on a JDM import site they see "twin turbo" and their damn heads spin around and shit!

THE LEGACY B4 MOTOR IS SLOWER THAN THE STI EJ20T!!! GET THAT THROUGH YOUR HEADS PEOPLE!!! IT'S ONLY TWIN TURBO SO THEY COULD MAKE THE POWER DELIVERY EXTREMELY SMOOTH LIKE A LUXURY CAR SHOULD BE!!! IT GIVES YOU ABSOLUTELY NO EXTRA POWER AND MAKES IT A PAIN IN THE ASS TO TUNE!! NOT TO MENTION IT IS IMPOSSIBLE TO FIT A B4 MOTOR IN A LEFT HAND DRIVE CAR!!!!

Not only that, but it's a standard EJ20 with nothing special other than a completely annoying black box ECU that can't be modified or piggybacked.

The STi motors are far more advanced, far more reliable, make more horsepower given the same modifications, have forged internals and variable valve timing, and are just as cheap!

I WOULD THINK THAT THIS WOULD BE A NO BRAINER!

[/rant mode off]



....no offense intended, I just get sick of hearing "Dood, im'a gonna get me one of them twin turbo EJ20SRKAEFDETTs and drop it in for $1k and I'll have 500 horsepower on da pump gas! Doh!"

I'm not saying you're one of those people, it's just what comes to mind every time I read "EJ20 twin turbo".

Thanks for asking though! You only learn by asking questions!
 

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Discussion Starter #13
Porter,

First off, no offense taken. I have to say I am very new to Subaru, and for that reason I will probably ask these questions. I rely on answers like yours for the information needed so as to not make a stupid move. So, therefore, thanks for the information.

I think I will just buy a RS and do some mods to it, that is all I really need for now anyway.

thanks again
 

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Sweet! Welcome to the club. Good luck in your search for an RS! They've gotten fairly affordable recently, though some schmucks seem to think they can upcharge for the "nicer" body style of the GC8 RS.
 

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I rely on answers like yours for the information needed so as to not make a stupid move.
you said that about porter :confused: you need to spend more time here ;) though he is right for once, although i should make a note that only the v7 engine has variable valve timing (and Na filled valves for that matter :drool: ). actually, are they still calling it an EJ20 in the latest STi?
 

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Ok, Im doin the JDM swap(got a killer deal on a clip) and i was wondering what the specs are on the engine. You know, like what turbo is on it, and what can i upgrade before the engine goes in the car. I know the octane thing will be a problem since all i can find is 94 octane around here. If anyone can point me in the right direction, i would appreciate it. The front clip is a 99 ej20 sti with low miles.


Thanks,
Greg
 
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