complete jdm front clip or usdm 2.0L?

[MixeD_MenacE]

i've been trying to keep up with some threads here and there but have never really seen a comparison type thread (could be wrong) dealing the pros and cons of swapping to a JDM motor vs a USDM motor.

basically the car will be daily driven, both in winter and summer (wonderful canadian climate). auto-xed and on a road coarse. simple bolt on mods will most likely be done in the future ( UP,DP, UTEC...etc)

what are the pros and cons with both the JDM and USDM 2.0L's?

finacially, reliability, mechanically, ease of install...etc.

as well as sources for swaps. thanks a bunch

please post your feedback

even if there is an existing thread, post it =D

cheers!

* Registered users of the site do not see these ads.

[stimpy]

JDM
pros:

• Typically a lot cheaper unless it's a late-model STi. Can often get an entire front clip versus just the USDM drivetrain (or less)
• Some may be pushing more power than USDM swaps, if it is STi it will probably be a LOT more
• Could land a TD05-16g, VF22, or other upgraded turbo
• Some are closed deck
• Some will argue that the transmission strength in some are stronger
• Some say that wiring will be easier if the doner and the donee are of the same model year
• Will most likely be below 30k miles

cons:

• Could be drastically more expensive if it's a late-model STi
• While few know the wiring for the USDM swap, even fewer know the wiring for the JDM swaps
• Could land something significantly smaller than a TD04
• Many opt for aftermarket engine management to ease wiring problems
• No ODB-II compliance unless wired by Lachute Subaru
• ECU upgrades must be sought across the pond
• Most engine parts are not found in the US
• Many upgrades are not compatible with the JDM engine orientations
• JDM ECUs are tuned with a higher octane rating and power may be down or not possible without additional octane
• Older engineering (not necessarily bad, just older)

-Jon

[stimpy]

USDM
pros:

• Easily found (for cheap, now that's another story)
• Parts can be sought at SOA dealerships
• Typical upgrade paths are out there and compatible
• OBD-II compliance if wired correctly
• Plenty of documentation to fully wire ECU
• Makes the 227hp on regular US gasoline
• Will be significantly cheaper than a late-model STi swap
• Newer engineering
• Can be found nearly bround new

cons:

• Some yards are charging way too much for the drivetrain (read: upwards of $5k for just the engine)
• Turbo is a little small
• Not as unique?
• Has more electronic complexities to be wired in
• Can be a lot more expensive than a full JDM swap
• Many drivetrains can be at or above 30k logged miles

-Jon

[stimpy]

Originally posted by MixeD_MenacE
finacially, reliability, mechanically, ease of install...etc.

as well as sources for swaps. thanks a bunch

Those answers can be found in the FAQ and other threads. However, just to sum it all up:

Financially, an engine swap is expensive. I am approaching $10k for my USDM swap with extras.

Reliability is easy. You are installing a factory turbo engine. If you go JDM, you will need to watch octane levels and possible wear due to the older engine.

Mechanical... well... uh... It is a turbo engine, but some are older than others in design. What are you looking for here? You want the best? STi Type RA Spec C with 6MT.

Ease of install? There is no such thing. This is not a Honda swap. Unless you are swapping from a USDM engine to an EJ207 wiring will be a whore. Mechanically, however, it is fairly straight forward as long as you know what parts must be swapped.

-Jon

[Homemade WRX]

As far as the US engine's go keep your head up and look around. I found mine with only 11k miles on it and got it for $2000
Take it easy, Micah

[Puckaveli]

Originally posted by stimpy
JDM

cons:

• ECU upgrades are almost nonexistant unless aftermarket engine management is used
  

-Jon

There are at least 5 ECU upgrades that I know off the top of my head. 2 for 96 and earlier and 1 98 and newer and 2 any year. Subaru changed the EPROM format in 97 for a larger airflow meter and different boost solenoids. The biggest change was when they went from having direct-fire ignition to having two double-ended coils and a set of hi-tension leads.

Power Engineering (sister, UK, company of ECUTEK) - Only for 98 and newer.
ScoobyECU - They can do any year remap.
ChipTorque - Any year
Fueltronics - 96 and older
Powerchip - 96 and older

[garface]

I have been told that JDM cars are OBDII by numerous people.

[stimpy]

Sorry Puck, guess I should stick to my USDM I changed that con.

garface, if I remember correctly, only the GD/GG chassis possess ODB-II compliant systems. Before that they used something else. I'm going off of a faint rememberance of a conversation I had with Lachute.... Lachute did say that they could work their magic on a non OBD-II JDM system and convert it; however, I have no idea what that consists of.

-Jon

[garface]

I believe Scooby Steve has a Ver. 6 RA which is OBDII compliant.

[stimpy]

--taken from www.scoobysport.co.uk--
Every Subaru manufactured after 2000 has On Board Diagnostics (OBDII), which monitor the efficiency of the original catalysts. If the downpipe and/or the up pipe are replaced with de-cat versions, OBDII will trigger an error code. The error code is P0420 “Catalyst below efficiency threshold”. This will also illuminate the Check Engine Light on the dashboard.

-Jon

[Scoobie Steve]

Garface is correct my swap has a OBDII compliant plug, but will not post OBDII is ready code. Stimpy 10g is getting a little high. I did my swap for slightly less but i did all the work myself.
If you do go JDM be sure to get a complete clip, with uncut wiring. Stimpy is 100% right about the wiring, I cant find anyone willing to even sell me a diagram for my car.
I have had no problems running 14-15 psi on 93 octane.

[stimpy]

$10k is a _little_ more than just the drivetrain swap. It is basically everything I have done to my car including shipping and tax for every part purchased. This includes wheels, lugs, tires, mounting and balancing, AccessECU, drivetrain and shipping, flywheel, clutch, downpipe, SVX master cylinder, brake lines, speed bleeders, full WRX brake conversion from drums, hydraulic pedal conversion from cable, a couple bushings, aluminum hood, up-pipe, axles, control arms, trailing arms, endlinks, sway bars, and many other parts I'm sure.

The reality of it is, you can spend a helluva lot on this stuff. And as I said before (somewhere), I have only spent around $5600 for all the drivetrain parts necessary for the swap. What most people don't realize is that you probably won't spend just what is necessary to get it running. You start thinking about how easy xx part would be to install while the block is out of the car, or how nice it would be to go ahead and spend the cake on yy part.

Just shop smart. Don't be fooled by how cheap some say it cost them because there are things forgotten and different cars require different parts.

-Jon

[supermoose]

ive talked to a guy at a local shop (who knows waay more about this game, tunes 290 AWHP wrx's all day) and he said teh usdm EJ205 swap into a 98 RS was utter hell. congrats to those on the board who can tackle the wiring, but im JDM all hte way

u can buy a decent clip (not libero usa's 100K mile one) for under $4000, i did myslf (60K mile JDM 94 STI)

and provided u have all the wiring, it will plug almost right in. we've got it slotted into a 93 L, tore off the whole front end (fenders, bumpers the works) to replace evey single bit of wiring on the car.

im assuming 80% of the guys doing ej20 swaps are using older L's, so the wiring is really compatible as opposed to the GDA stuff. no elec speedo poo, no fuel controller thingybob, no obd100, etc. if u are in cali and are screwed by smog, i suggest u find a slightly friendly (disthonst) smog man or just run cats and have a clean install. mike shields has a 96 JDM WRX ej20g in his 94, and his car passes smog. legally. ive personally played with the car. its fast

if u want to make the wiring simple, buy a good condition (uncrashed clip ideally) and do a RHD converison. it will all plug right in, i dont care what somone who has heard of it etc say, ive personally (with my own hands that are typing right now) torn apart 2 similar year cars, (94 JDM STI, 93 usdm L) and i feel that a RHD converison would be simple as hell. in that case, u dont need to do any wiring at all. just plug in the rear harnesses and u are set. run teh JDM AC, the JDM rack, JDM heater/AC boxes with crazy cool electronic climate control, and u will have a full spec WRX with ZERO wiring.

ZERO wiring, if u whine about not being able to drive RHD, u arnt a man, im sure u would drive a skyling if u had the chance to. besides the rest of the world is fine with it, if u have a brain u can figure it out in a couple days.

if u want to keep LHD (like my friend did on our conveison) then u need to only extend the harness. this involves cutting a mad bundle of wire (one at a time) and making them longer for re-routing. i could train a monkey to do this. slight brainwork is required tofigure out which wires, etc where they go, but if u can change a brake pad u should be able to figure it out.

we are using the full JDM harness, full JDM motor, radiator, accesories, ecu, etc. the swap shoudl be completed this weekend or next, and we;ve spent a 6 weeks working on it. 1.5 days a week (my budy lives at school 1 hour away from his car)

yeha. another point the USA ej20 guys are failing to mention.

the USDM GDA gearbox sucks. eveyone knows that, it is a horrible mate to the engine, designed simply to beat the man on emissions, 3.9 final drive and a 3rd gear that can hit 100mph? no wonder they cant power outa corners on teh track, they have the wait until the gearing will let the motor make boost. sux.

strength is not the issue here, if u arnt a lead-footed monkey, u can drive a 300 hp GDA no problem w/o any gearbox worries, its simply the mechanical gearing.

the JDM GDA (wrx-nb or whateve its called) has a 4.11 gearbox, i would bet my car (basically a STI v6 with a DOHC ej25) that if u were to rate the most effective modification from swapping a part from the JDM gda to the usdm one, that the gearbox would be the most important asset. screw the extra 20 ps it has, or the 9:1 compression or the tgv issue, its the frekin gearbox that makes it pull harder than hell compared to the USDM one.

simple mechanical advantage.

okay, so unless u are like aspen25 and buy a GDA for $2400 (complete car) dont bother with a USDM ej205 swap. its not worth it.

FYI we are getting the JDM ej20g (with TDO5 turbo) into my buddys car for under 2500 easy.


the gearbox is in my car, and makes things faster than hell.........


sorry for my ranting. i suppose the USDM has one redeming value, its newer and u can get them with really low miles. although most likely abused by some moron who crashed it.

i bought my JDM front clip UNCRASHED. NON crashed,

parts for JDM? easy.

bottom end: crank/rods = EJ18 parts. most likely u will have for free bc thats what u are pulling outa it.

air filter? same as the EJ18
oil filter: ditto
turbo: im sure any bolt on WRX one will fit
header: i spoke to HKS personally in asia and they said that their header will fit
up-pipe: dont need on. its already no-cat and made outa incronel
downpipe: same deal. most likely usdm will fit. u probbly dont need it though, i dotn think 280PS will be slower than any exhaust modded GDA
some parts should be compatible with USDM legacy turbo. that is only a suspicion though
rallispec can get u gaskets (although USDM ej20 shoudl work fine)
clutch is identical to a USDM WRX GDA clutch. i have one in my attic. i have a exedy USDM GDA clutch on my 94 JDM STI trans
TD05 turbo issue: if u are afraid of a small turbo, simply look up the vin. u shoudl do it anyway before u drop 2g's on anything. u will be able to figure out exactally what u are getting. besides, whats so bad with a small turbo. 240 or 260 hp isnt anythign to be ashamed of, last i knew the usa td04 cars only came stock with 227....


yeha, sorry i dont mean to offend anyone, as u can see im in the severe boat of JDM ej20. i simply dont like the junkyard markup of the GDA motors, and the severe complexity of the wiring.

i suppose when we are discussing motorswapping, 1 thing comes up beyond all other things. WIRING. and simply put, my personal experiance in wiring (the JDM) or the lack of wiring ive done, makes me severly biased towards that side. im hella super afraid of wiring.


if u guys haev any questions or need advice on JDM clips, find me. ive been hunting them for years now.


peace

h

[stimpy]

ive talked to a guy at a local shop (who knows waay more about this game, tunes 290 AWHP wrx's all day) and he said teh usdm EJ205 swap into a 98 RS was utter hell. congrats to those on the board who can tackle the wiring, but im JDM all hte way

Funny, I-Speed says the older Imprezas are the worst of the cars to work on. Dig around for some of their stories.

im assuming 80% of the guys doing ej20 swaps are using older L's, so the wiring is really compatible as opposed to the GDA stuff.

I wouldn't make this assumption. Take a look at the swappers out there and a good half of them are newer cars (read OBD-II and up). The person who started this thread has an RS... If you are one of those with a newer car, in my mind, it would be best to stick with an engine of equal or newer year. I've heard California, for instance, requires the engine be of equal or newer year and all emissions equipment must be intact. Now many of us may bend the rules for emissions, but it all comes down to how much hassle you want when your emissions date comes up each year. Again, a severe negative for me since I want to be as close to legal as possible.

Most of your points are valid, though mileage plays a large roll in my decision. Installing a high mileage motor, superior gearing or not, may imply a transmission rebuild and/or other things. That is not to say that the USDM swaps are exempt from this either, though. It is hard to tell what may be needed until the car gets up and running. Again, that can apply to both.

turbo: im sure any bolt on WRX one will fit

Not so. The TD05 as well as the IHI RHB52 (VF11) has a right angle inlet, not the straight inlet of the new turbos. Bolt-on it is not. I also believe Jaxx said the turbo is cocked in a slightly different manner as well.

the USDM GDA gearbox sucks. eveyone knows that, it is a horrible mate to the engine, designed simply to beat the man on emissions, 3.9 final drive and a 3rd gear that can hit 100mph? no wonder they cant power outa corners on teh track, they have the wait until the gearing will let the motor make boost. sux.

That is all hearsay. You tune the car right and with the proper components and you can be making good boost at 2k rpms; which, coincidentally enough, has absolutely nothing to do with gearing. Boost and gearing only really overlap when the gearing limits the speed of the car which, in turn, limits the engine speed.

If it is an L swap, the gearing will play a larger factor. However, I have owned a 4.11 EJ25, a 3.9 EJ20, and a 3.9 EJ22 and I can say that while the 4.11 would be fun in the EJ20, it isn't necessary. I've autocrossed the 4.11 and the 3.9 and on some courses the 4.11 is perfect, some courses it is too short and needs a 3rd gear selection, some courses the 3.9 was perfect, and some it was a touch long and in need of 1st. For the RS guys, they already have the 4.11 in their car and they usually just source the engine, not the entire drivetrain.

You wanna road race? Get the 6MT box. You want to rally? Get the Type RA 4.44 box or some other close-ratio. Talk to some of the RS-T guys and they will tell you that the gearing is too short. Talk to some with a 6MT swap and they will tell you that they are suffering bigtime at the track. The USDM WRX gearing lets you hit 60mph in 2nd for better 0-60. Take your pick.

At some point, the intake manifold was also shortened to provide room for a larger topmount. If you have one of the older manifolds (similar to the EJ25 design) you will not be able to use the the newer topmounts without work. Just a little side note.

Wiring will not be too bad I don't think. I've dug around and worked on the wiring for my car for a number of hours already and it is pretty straight forward. Soldering cannot be avoid when going with a swap like mine, but I'll gladly dig in for modern-day factory turbo.

TD05 turbo issue: if u are afraid of a small turbo, simply look up the vin. u shoudl do it anyway before u drop 2g's on anything. u will be able to figure out exactally what u are getting. besides, whats so bad with a small turbo.

I think you misunderstood me. The TD05 is comparable to a VF30, but with better spooling characteristics. Not a small turbo...

-Jon
Good discussion...

[MixeD_MenacE]

wow thanks for the insight guys, keep the comments coming =D i enjoy looking at different angles of the swap.

[Matt Monson]

Stimpy,
I am going to take a slightly different interpretation of Super Moose's comments regarding most people doing these swaps are using older L's. Not only do I agree with that from what I have seen around multiple forums, but I might have an insight into why the wiring may be easier on these cars...

If one is getting a JDM front clip from a GC/GF chassis impreza and dropping it into the same, the wiring should be similar. The problem conversions I have heard about are largely GD chassis USDM swaps and wiring harnesses going into GC/GF chassis... I am just speculatiing here, but this makes sense to my pee wee brain and would explain why same year donor to donee swaps are smoother. This should apply to this '98RS as well, if I am correct.

Beyond that, the deal with California is more than just having the same year or newer donor car. To make it truly legal, it must be from a USDM donor and have been sold in the state of California in that year. This would be why I-speed uses USDM donors. Since the WRX didn't hit until MY02, you couldn't use a V6 STi swap in a CA car and make it truly legal...

But there is an old trick we used to use with Honda B16 swaps. The Del Sol was first sold in CA in 92 and 93 with a B16. We just lied and said the donor was a Del Sol even though it came from a '90 JDM CT-R. You just set it up bone stock for your Referee appointment(which is a multiple hour inspection you go through after the swap) They ran a little rich and you messed with the advance for the testing and they passed both the visual and the sniffer.The Ref gives you a BAR sticker for your doorjamb and you go home and put on all your JDM and Mugen parts on and are "street legal",

There are guys doing this with EJ20 swaps as we speak claiming they are USDM donors...

And in case it was mentioned and I missed it, USDM Subaru's went OBII in '97...

[stimpy]

Originally posted by Matt Monson
Stimpy,
I am going to take a slightly different interpretation of Super Moose's comments regarding most people doing these swaps are using older L's.

I have no problem with people disagreeing with what I say. It is definitely not the right way to do it, just A way. I must rebute, though. While wiring length may be different between the GD/GG chassis and the GC/GM/GF chassis, the only thing drastically different is going to be the fuel controller (on the newer cars). The rest is merely incorporating the engine harness into the existing bulkhead wiring harness; something that must be done no matter which engine/year you use. If you are crazy enough to swap the entire harness then yes, it will be a lot more compatible to stick to the same chassis and even the same chassis year.

With all that said, my own personal count is this:
MY94 -> USDM (Eby)
MY96 -> USDM (stimpy)
MY93 -> JDM (Jaxx)
MY93 -> JDM (Jude DeMeis)
MY99 -> JDM (underground-mpyre)
MY00 -> JDM (garface)
MY00 -> JDM (a Canadian fellow whom I have forgotten the name)
MY00 -> JDM (d00f)
MY99 -> JDM (AWJunkies)
MY98 -> JDM (Scoobie Steve)
MY00 -> USDM (Scooby South)
MY94 -> JDM (Mike Shields)
MY95 -> JDM (Simon Sirin)
MY93 -> JDM (supermoose)
MY94 -> USDM (Homemade WRX)
MY98 -> USDM (Trey Cobb)
MY00 -> USDM (liberty2000rs)
MY95 -> USDM (Aspen_2.5RS)
MY93 -> JDM (suberboy)

That is all I can think of for now, but it doesn't look very conclusive to me. I'm sure I-Speed could chime in with their counts too.

Originally posted by Matt Monson
And in case it was mentioned and I missed it, USDM Subaru's went OBII in '97...

Sorry, but I disagree. Some Subaru's went OBD-II as early as 1995 while it was federally mandated in 1996. My 1996 is most definitely OBD-II and will stay so even after the swap.

I do thank you for your input on the Cali swap scene. I haven't bothered to research it much since I'm in Utah. That also goes to show that though they do a severe check on everything, they don't actually verify VINs and engine serial numbers. I'm legel if I can just pass OBD-II emissions, though I will have as much paperwork as possible in case it requires more in later years.

-Jon

[Crawford/I-Speed]

Here is a brief list of the ones ,I can remember we did, of the top of my head:

Adam 98 RS USDM Conversion
Eddy 98 RS USDM Conversion
Chris 97 obs USDM Conversion - PITA
Steve 99 legacy gt USDM Conversion
Kevin 98 Legacy gt USDM Conversion
Jeremy - seattle 98 Legacy gt USDM Conversion
Gary 99 RS USDM Conversion
Gary 98 OBS USDM Conversion
Craig 99 RS USDM Conversion
Medwyn 98 RS USDM Conversion
Bill 99 RS JDM VII Conversion W/ usdm and jdm harness
Andrew 98 RS USDM Conversion
Steve - seattle 00 RS USDM Conversion
Chris 99 L wagon USDM Conversion w/special sauce
Chris 94 L sedan USDM Conversion - PITA

Ones due before New Year
Mike - seattle 98 RS
Mike -San Jose 95 L
Neal ???
Bradon 98 Legacy GT

Chris

[Soon2Bgreat]

just to add i've got 2001 jdm sti ver7 swap, no fuel pump controller. The fuel pump had to be wired in on it's own and not with the rest of the car, so it has it's own sort of little antitheft, kill switch device. It runs a little rich but not at wot. I have the stock rs gears with 4.11 ratio and i want the 4.44. That's all.

[supermoose]

my argument on wiring is this:

i am a monkey. i can easily look at 2 differnt clips and 2 complete wiring bundles and take enough pictures to figure out what shoudl go where after i tear them both apart.

why bother with splicing stuff, and hybriding 2 harnesses, when u could simply stuff the JDM one in, look and see what needs to be extended and then extend them all. if u have a front clip, u dont need to intergrate both harnesses. completely remove the like year harness and then make the JDM one longer and plug everything in.

everything will plug in BC they are like year.

if u could do that with a USDM one, that would be most ideal. i suppose if u were doing GDA 2.5rs to EJ205, i guess it would work. most likely, that is not the case though.


yeah, the only things i can appreciate with a USDM swap is that 1- u COULD take it to the local dealership anad have them work on it if it needed a h-gasket or somthing etc-, and the technical legality issue (which i have no regard for personally)

JDM gives more sho points!!!!!!!
RHD CONVERISON!!!!!

yeah. if i EJ20, ill be doing RHD as well......

h

[supermoose]

mikes shields car is a 93 impreza with a 96 JDM wrx

h

[Matt Monson]

Stimpy,
For a second there I thought you were listing all the conversions you had personally performed and was going to say you were too modest for calling it short and non-comprehensive...

Not having done the conversion myself, as I said above, I was speculating why it may seem easier, and supermoose provides a pretty good explanation on his end. And of course you are dead on with idea that there is no absolute right way in this. I-Speed obviously has it dialed by their method. To me the full re-wire method seems simpler and when I get my project GF or BF will likely go the strip and re-wire method myself. I only participated in one DX to SI-R civic conversion( my own car wasn't V-tec compatible because of the AWD tranny, so it got a ZC), but I always thought it would been easier to just put in a new harness.

Now if the I-speed guys (hint hint) were to market a conversion loom like some of the Honda and Nissan shops, I think they could up their retail sales and still not hurt their conversion business. I know I would likely buy one if it was plug and play...

[garface]

I think ever year is different and even worse there are differences from car to car.

[Crawford/I-Speed]

Each MY has its differences. We have tossed the idea around about making "loom" kits. However, sourcing all the correct connectors has become a huge obstacle.

A few xtra notes:
The Wiring difficulty decreases as you up go up in MY (93-02 impreza).
Converting from OBD I to OBD II is a PITA
Of course these things matter more to those who want a smog legal car

Chris
I-Speed USA
cescamilla@i-speedusa.com

[supermoose]

poo.

i-speed, u guys do an early cars to JDM motor swaps? i know u guys have a GDA WRX-NB swap with AVCS, so u guys do do JDM motors.

smog issues,

to my knowledge if a car:

passes visual, pases the sniffer, and has motor same year or +, then it should work right?

so a JDM 96 ej20 in a 93 is totally smog legal right?
im friends with mike shields in LA, and his car had no problems getting a smog cert. but by the rule of the law, what is legal?

the ease ive had so far with my own personal conversion, im quite sold on the harness transplant issue. how long do you guys spend on wiring conversions? i know u guys got mad wiring skils, comparitively speaking- how long would a full harness swapout take for you pros?

h