JDM EJ20tt

[spooln30]

Well today I ran into a huge problem, my headgaskets are starting to go. I planned on swapping in a Version 6 STI engine but I just can afford it right now so I'm looking into the twin turbo jdm Legacy engine/ trans/diff swap instead. I know the reason they don't fit directly into out cars. Couple of questions about these engines.

1: Can you swap this engine in with the twinturbos and what modifications will I need to do, like the brake booster and subframe? I've read something about the BMW 7 series booster?

2: How strong are these engines and are they a open deck, do they have forged pistons? I've read they do.

3: Which version is the best to get. Ej20h, Ej20R or the Ej208 which is the 3rd gen TT engine.

4: If I wanted to make it a single turbo right away what US market parts would fit? I'm thinking the USDM WRX 02-07 stuff would work, for the exhaust header and fuel rails?

5: I might want to run a AEM so what AEM would work? Also thinking the WRX 02-07?

 

Thanks for any info you guys can provide.

[spooln30]

Forgot 2 things.

What clutch would work with this set up as I would get a better one right away and is there a direct fit drive shaft? Would a 96-99 Legacy manual trans drive shaft work with the jdm swap?

[koiracer]

Have you priced headgasket work yet?

 

I know some about the twin turbo engines. I can help with a few of the questions.

 

1: the only issue is the steering shaft. It goes in the same spot the "2nd" turbo sits. I have read about people fabbing up a custom steering shaft. But I think it is more trouble than it is worth on that aspect.

 

2: Not sure on the specs of the engine, but I have read numerous articles regarding the engine's performance. They have a notorious "dead spot" when the turbos switch over. I believe (correct me if im wrong) one turbo is for low end, and then it switches to the other turbo for the high end (never running at the same time).

 

3: ?

 

4: I have seen it done a few times, but not sure what exactly was involved.

 

I would consider new headgaskets and waiting until you can do any other engine besides the TT set up. To be honest, I have never seen a TT into a USDM car.... maybe for a reason.

 

I dont mean to discourage, but I hope people can chime in with more useful info.

[Zues Marine]

i can absolutely promise you this will be more trouble than it is worth.

 

the ac stuff is completely different as well as a lot of connected circuits for the jdm motors, like the digitized ac stuff for example

 

massive firewall modification or a very long and grueling process of converting to single turbo

 

its better to get a ej20g at the minimum if you're considering this route

[Sludgeroo]

The ej20tt is unfortunetly such a tight knit design that it truly needs to run the jdm ecu which is illegal in the US, or you'd have to run a standalone as you know.

 

The design is literally built around a RHD Legacy.

 

Im not saying you couldn't do it or you shouldn't do it, but as a cheaper alternative it wouldnt be fiscal.

 

Not sure if AEM makes a piggyback, but I know for sure that Mine's and Zerosports both make aftermarket ECU's.

 

Again... good luck.

 

I've also heard (as im not in japan/europe) that the tt setup is very finicky and a PITA to deal with, im comparison to its power benefits.

 

Youre way better off building a hybrid or 20g.

 

Just my .02

[spooln30]

I'm a mechanic so it would only cost me the parts and machining but fixing the headgaskets isn't an option due to the previous owner not changing the oil when they should've. It's a tad sludged but it runs good. There are 4 guys I know of here in WI who have swapped in these motors, and 2 went single and the other 2 actually have the twin turbos. I don't have their contact info so asking them isn't an option unless I get a hold of them. I don't see how converting it to a single turbo would we hard especially if the Wrx stuff fits. I did it with my jdm 2jzgte and it cleans up a bunch of room. Almost every twin turbo will have the "dead spot" when the second turbo kicks in and that can be worked out with adjusting the wastegate and solenoids. I would think that the USDM Wrx ej205 header and fuel rails would work in the TT engine. I also can't see a massive firewall modification nessesary because it's not like the engines are close to the firewall. With the AC I'm sure I can use my compressor along with all of the lines if I convert to single turbo. I would more than likely install a FMIC, I'm not a fan of TMIC as they get heat soaked fast due to the placement.

[fahr_side]

You should ask GEE-OTTO. He has all sorts of knowledge on these engines, swaps etc.

[spooln30]

I'm not looking for a piggyback I would run a standalone. Running a JDM is illegal? I know plenty of guys who do and here in WI in 80% of the state there's no emission testing. When I registered my 99 LGT I did so in northern WI I don't ever have to take a emission test so running a JDM ECU isn't a problem for me at all. LOL.

I am sure if I would go this route it would be a single turbo so it would be finicky IMO.

[spooln30]

Another question guys, are all WRX rear diffs the same with the same gear ratios? I can get a jdm Wrx engine and trans with ECU for $2k and I found a guy that has a bunch of almost brand new rear diffs for cheap and I'm thinking of piecing it together that way. I would probably need the axles for the rear that fit the Wrx diff as well right? He lists the Wrx ratio as a 3.70 and he has a STI 3.90.

[fahr_side]

A lot of JDM models went to OBD-II much later than say the USDM. Even if you don't have to face a sniffer test they may expect that a car which was mandated to have OBD-II to be able to pass readiness monitor at a minimum.

Most of the JDM models from this era have Hall-effect two wire sensors that differ greatly from those on cars sold elsewhere, and are incompatible with the ECUs. This is where you'd have problems.

[spooln30]

Farhside here in Wisconsin there is no sniffer testing only plugging into the OBD2 and checking for codes and readiness monitors. They used to do the roller testing on OBD1&2 but they got rid of that thus eliminating any and all testing of OBD1 and prior vehicles, then they got rid of the DMV emission testing stations altogether and now just have certified repair shops do the testing on only OBD2 vehicles. Also only the larger counties have emission testing, like I said only about 20% of the state. The rest don't have yo take any test of any kind, you just get your license plate sticker renewal in the mail and pay to get new stickers. There's a part on the registration paperwork asking " vehicle kept in the county of" and you fill in where you want. My family actually has land in such a county so it just makes it that much easier but I know people who don't and they've never had a issue.

[spooln30]

This is one of the many reasons Wisconsin rocks, plus we have a kick a$$ Governor, Scott Walker!!! Who by the way will be our next President.

[fahr_side]

Enjoy this freedom while it lasts!

[Sludgeroo]

Not taking away your mechanical ability, BUT it is built around that firewall. Think about all the stuff ran thru the firewall that is aimed a certain direction.

 

If your trying to do this as a cheap alternative, I have no idea why this is your choice.

if your trying to do a crazy swap on a motor to just do it, more power to ya.

 

But headgasket and possible rebuild vs. Most difficult subaru engine to fit (f**k im sure an eg33 may be easier) don't make sense to me.

 

And they would plug your car in and the motor from japanland will say does not work and make the inspection station confused.

 

Idk, I've heard that motor is garbage, you asked opinions and knowledge and ya got em.

 

Good luck

[DOHCEJ22E1]

EJ20R, single turbo conversion, & a standalone.

Have we forgotten Brock's car already? Look him up.

My next few paragraphs will be from what I have personally seen/experienced.

The EJ20R & the EJ208 are 2 completely different engines & shouldn't be classified in the same sentence unless you're generalizing twin turbo EJs.

The 20R is STRIKINGLY close to our own 25D except obviously it's twin turbo, 2.0L, & it's JDM but things can be swapped between the 2, like camshafts, cam gears, crank gear, & our USDM ECU will run them.

 

However, that is all. Our ECUs will not run the turbo aspect of the engine. The vacuum box & various other solenoids that have nowhere to wire up to if you were to just drop it in. As for calling the 20R a piece of crap, well, in twin turbo format, it is a piece of crap. Hot spots, overheating, 2 turbos coking the oil, it was a hot mess created by the R&D of FHI. On the bright side of everything, the 20R is practically the twin turbo variant of the EJ20K. The even share the same exact aggressive & very high profile camshafts (reported to be Subaru's most aggressive set from the factory).

 

Running the 20R as a single turbo would probably be no more finicky than a WRX swap. Also to add, EJ20G twin turbos are more closer to the 96 25D engine that we have here & parts (cams, crank gear, can gears,) can be swapped from that engine to ours as well. They have the same limitations though & must be used with a standalone.

 

Power differences between the engines:

EJ20G - 250bhp. Phase 1. Replaced by EJ206.

EJ20R - 276bhp. Phase 1. Replaced by EJ208.

EJ208 - 276bhp. Phase 2, OBD1 & OBD2 in its final forms. Replaced by superior EJ205 & EJ255.

[subikid90]

Have you priced headgasket work yet?

 

I know some about the twin turbo engines. I can help with a few of the questions.

 

1: the only issue is the steering shaft. It goes in the same spot the "2nd" turbo sits. I have read about people fabbing up a custom steering shaft. But I think it is more trouble than it is worth on that aspect.

 

2: Not sure on the specs of the engine, but I have read numerous articles regarding the engine's performance. They have a notorious "dead spot" when the turbos switch over. I believe (correct me if im wrong) one turbo is for low end, and then it switches to the other turbo for the high end (never running at the same time).

 

3: ?

 

4: I have seen it done a few times, but not sure what exactly was involved.

 

I would consider new headgaskets and waiting until you can do any other engine besides the TT set up. To be honest, I have never seen a TT into a USDM car.... maybe for a reason.

 

I dont mean to discourage, but I hope people can chime in with more useful info.

 

 

^ I agree with this comment. The single turbo mod is not to difficult and has been documented (nasioc, rs25 or uklegacy).

[Bandit240]

Hmmmm. Reading all this makes me wonder what the chances of finding a JDM front clip and swapping all the needed bits into my postal. It's RHD, so it should be doable.

[DOHCEJ22E1]

Hmmmm. Reading all this makes me wonder what the chances of finding a JDM front clip and swapping all the needed bits into my postal. It's RHD, so it should be doable.

 

Just get the engine/wiring harness for it & the car & you're smooth sailing. The twin turbo setup will fit & drop with in our RHD models.

[Bandit240]

I'd rather have a whole front clip. I like the climate control system.

[Sludgeroo]

If you found a postal and did a 6mt swap and put something wacky in it like the eg33 or ej20r and have a really unique ride. Fo shooo

[Bandit240]

I've got the postal already. It's in need of engine work right now too. Been thinking about buying a little nicer Legacy for my wife and use the drive line from my L model in the postal. That would make the postal 5-speed at least.

 

I've also considered the EJ25 block and EJ22 heads combo.

[Sludgeroo]

High comp would be cool. I have a 255 block with a spun 4th in my garage right now I gotta figure out what to do with it.