Thread: EJ207 Info
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Old 07-24-2012, 08:09 PM   #2
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
02 WRXstiV9 Spec C


Swapping an EJ207 in a USDM GDB body


The standard "swap package" that most vendors make available these days, is the complete engine, usually that radiator hoses are cut, the heater core hoses are cut, the oil radiator hoses are cut, the accelerator cable is cut, no pipe is included past the turbo inlet (none of the air filter piping and bellows), the alternator witing is cut and sometimes the same is done with the power steering and A/C piping.
Sometimes that piping is properly removed. But when it's cut, they try to make it into a cap, by flattening it, to protect from dust.
The engine harness is included, ends at the main harness connectors on the engine, left and right.
The turbo is included and the downpipe.
The BCS and hoses are many times included.
The fuel supply hoses are removed.
The front O2 sensor can be included.
The ECU is included and many times a clip of the ECU harness.

Most have the engine run by the JDM ECU and the USDM ECU should be able to start the engine up and run it for short durations, recommended is to disconnect the AVCS at the solenoids when you do this.
Reflashing with Ecuflash editing with Romraider and using the tactrix cable should be no problem.
I have not read of anyone using accessport with these ECUs
Connecting an EcuTek delta dash cable to the JDM ecu is no problem, the logger works nicely.

Always keep in mind requirements for inspection. One can be that the year-model reported by the ECU connected at inspection has to match the year-model of registration.
The USDM wiring at the OBD2 port left unmodified will make for the USDM ECU talking to whichever unit is needed (State inspection, or OBD2 reader), but once the JDM ECU is in, it may not talk to handheld OBD2 or State computers, but will talk to a tactrix cable.
One consequence is that if the JDM ECU has a code, most likely you won't be able to read it with a handheld scanner, but you will be able to work with a laptop and tactrix. The handheld scanners "speak" several protocols, some are reported to connect, some not.
There is a pin at the OBD2 connector that is ported diffrently for the JDM, for a V9. The JDM connector may not be called OBD2 anyway.

The right way to do a swap is to acquire the manual for both cars, including a full set of wiring diagrams. Then you don't relay upon internet information. IAPerformance can help you with JDM documentation.
Wiring always differs slightly for the USDM from one year to another and causes minor headaches.

If you have a 02-05 USDM WRX
You're swapping a cable throttle engine in the same type of car, the harness plugs at the ECU will fit.
You can keep the 5 speed, just use a 5 speed flywheel and clutch kit for a WRX.
The A/C conduits can be made to fit, just like the powersteering ones, or you can swap in your USDM items.

-If you swap a V7
Then everything will fit, only if you're swapping into a 2005, the polarity of the Neutral safety switch has to be changed. Check the reading of NSS status in the Romraider logger before trying to solve this.
Also, a 2005 body may have a sensor by the turbo inlet tube, that remains unplugged at this point. Depending on the year, there may be a need to unplug the air temp sensor on the intake manifold.
Your existing downpipe will fit.
You will need to buy the IAP AVCS wiring kit, or follow
to enable AVCS. The NSS will have to have proper polarity for it to work.

-If you swap a V8
Then if you're swapping into a 2005, the polarity of the Neutral safety switch has to be changed. Check the reading of NSS status in the Romraider logger before trying to solve this.
Also, a 2005 body may have a sensor by the turbo inlet tube, that remains unplugged at this point. Depending on the year, there may be a need to unplug the air temp sensor on the intake manifold.
You will need to buy the IAP AVCS wiring kit, or follow the write-up, to enable AVCS. The NSS will have to have proper polarity for it to work.

The exhaust will be different, your existing downpipe won't fit.
A cheap option is to cut the neck of the twinscroll downpipe and get it welded to whatever downpipe you have.
A high grade stainless existing downpipe may require you buying from ebay the high grade stainless twinscroll downpipe bellmouth and getting that welded to your existing unit.

The front oxygen sensor won't reach to the connector most likely, so you will have to re-use your USDM front oxygen sensor (WRX only) and weld a bung for it in the downpipe, where it belongs with these engines.
If you've re-used the stock twinscroll downpipe bellmouth, you already have the bung there.
It is almost impossible to check the function of the JDM front O2 sensor from a twinscroll against that of a USDM front oxygen sensor from a WRX.
But everyone is using them (USDM Sensors) and nobody had problems because of this.
As a note however, mine was tested by another board member and it could not be made to work on a USDM WRX, no matter how the leads were swapped. Maybe it was just defective..
K2Kevin has used the JDM twinscroll, short lead, front O2 sensor and found it puts out the same type of signal as a USDM WRX EJ205 front O2 sensor.

-If you swap a V9
Everything above applies, except, the NSS will work unmodified if the USDM body is a 2005, but has to be modified for earlier USDM bodies.

Be careful with V9 that could be imobilized. They can be swapped in, but you need at a minimum, the immobilizer box, the immobilizer antenna (located in the ignition switch ring) and the keys. Everything has to be from the same car, matching set. Otherwise, Subaru would have to reprogram to make them work together and SOA could most likely not do this, even if they wanted to.

Swapping an immobilized ECU is nothing exotic, people do this with USDM ECU's all the time, it's just a matter of not being stuck with an un-matching set. In the EJ207 community this has not yet been documented however.
In the USDM community it is being said that the cluster is not necessary in the swap kit and it's only a passthough.

I think I need to make a note here: The very late V9, such as in a 2006-2007 may have a bad surprise for the swapper that acquires a Spec C, with ECU and all immobilizer components. The Spec C ECU may be looking for a fast steering rack and if not finding it, disabling the ABS. This is done by the steering angle sensor that these have.

If you have an '06-'07 WRX or '04-'07 USDM Sti

There is a fundamental gap here. The JDM never had Sti with single AVCS, drive by wire, non canbus, 32bit.
There will be a need to pass state inspection as well.
The plugs at the JDM ECU will not match the connectors in the USDM 32bit harness.
Converting the harness to make the JDM ECU fit can probably be done, but it's a one way street as far as ever plugging the USDM ECU back in.
The immobilizer of the USDM ECU feature will be lost too.

This swap has been successfully done by 4 members on the board so far, via machining and adapting the cam sensors and swapping 32 bit USDM cams, so that the USDM ECU can control the JDM engine. Either somebody is going to make available a swap kit for this option, or you will need a machine shop assistance to get the swap to work, or you modify the harness at the ECU, and understand that state computers will never talk to it, so it's a race only vehicle.
This swap has also been accomplished via cam sensor replacement with aftermarket ones and swapping the cams, by K2Kevin and he posted in this thread. Apparently, the crank sensor is the same and only the plug for the temperature sensor has to be changed.

If you have a GRB WRX or Sti
There are some indications that at least one person has tried this, maybe somebody will post some information about this.

Maintenance, Owner's Manual

This is from the JDM Owner's manual, for EJ207 Sti Spec C and WRX. I am using an automatic translator and cleaning this up.

MT : マニュアル車
AT : オートマチック車
STI spec C 34B19L
1.5 55D23L
2.0 MT車55D23L
2.0 AT車65D23L
スバルモーターオイル SM 5W-30
スバルモーターオイル SM 0W-20
スバルモーターオイル SL 5W-30
エルフ 10W-50 レ・プレイアード10W-50
1.5i、1.5R 約4.0 約4.2
WRX AT車約4.0 約4.2
WRX MT車約4.0 約4.3
STI、STI spec C 約4.0 約4.3
STI spec C空冷オイル
約4.0 約4.6
10,000 kmごと、または12か月ごと
交換時期10,000 kmごと
1.5R以外60,000 kmごと
1.5R 100,000 kmごと
オルタネータ パワーステアリング
10 kgf)の力で押したとき
9~11 mm
10 kgf)の力で押したとき
9~10 mm
1.5i ※PFR5B-11 NGK 1.0~1.1 mm
1.5R ※ILFR6B NGK 0.7~0.8 mm
WRX ※PFR6G NGK 0.7~0.8 mm
STI、STI spec C ※PFR7G NGK 0.7~0.8 mm
交換時期100,000 km(白金プラグ使用)
遊び指で押して1~3 mm
約300N(約30 kgf)の力
85 mm以上
1.5 車約10~20 mm
2.0 車約3~13 mm
――― 80 mm以上
約200N(約20 kgf)の力
7~8 ノッチ
STI spec C 3.0
1.5i、1.5R 無鉛レギュラーガソリン使用約50
WRX、STI 無鉛プレミアムガソリン使用約60
STI spec C 無鉛プレミアムガソリン使用約50
交換時期50,000 kmごと

Battery Model MT (manual transm.) AT (auto transm)
STI spec C 34B19L
2.0 MT car 55D23L
2.0 AT car 65D23L

Engine oil
Subaru Motor Oil SM 5W-30
Subaru Motor Oil SM 0W-20 (Only non-turbo car)
Subaru Motor Oil SL 5W-30
Elf 10W-50 (performance)

Oil Capacity: 4.0 - 4.2 liters WRX AT car 4.0-4.3 liters WRX MT car
(changing oil and filter)
STI spec C air-cooled oil Cooler 4.0-4.6 liters

Oil Change intervals Every 12 months or 10,000 km, whichever comes first
Use a genuine oil filter, for no more than a 10,000 km interval

Fuel filter
Use genuine parts fuel filter, replacement interval 60,000 km

Accessory Belts
Amount of deflection of the belt
(during inspection, at the belt center, when you press with a force of 10 kgf, 100N) 9 ~ 11 mm
Amount of deflection of the air conditioning belt
(during inspection, at the belt center when you press with a force of 10 kgf, 100N) 9 ~ 10 mm


Specified spark plug, by car model

Car model Part Number Manufacturer Electrode gap
1.5i ※ PFR5B-11 NGK 1.0 ~ 1.1 mm
1.5R ※ ILFR6B NGK 0.7 ~ 0.8 mm
WRX ※ PFR6G NGK 0.7 ~ 0.8 mm
STI, STI spec C ※ PFR7G NGK 0.7 ~ 0.8 mm

Replacement interval 100,000 km (platinum plug.)

Pedal Play
1 ~ 3 mm by pressing with finger
When depressed (about 30 kgf) about 300N
Gap from pedal to floorboard 85 mm or more

Pedal play (pressing with finger)
10 ~ 20 mm 1.5 car
3 ~ 13 mm 2.0 car
Gap to floorboard 80mm or more

Parking/Emergency brake
When pulling slowly at 20kg F/200N 7-8 notch

Tire pressure see page 8-6

Washer tank capacity
All models except Spec C 4.0 liters
STI spec C 3.0

Fuel tank
About 50 liters 1.5i, 1.5R unleaded regular gasoline use
About 60 liters WRX, STI unleaded premium gasoline use
About 50 liters STI spec C unleaded premium gasoline use

Air cleaner
Element Use genuine parts air cleaner element 50,000 km replacement interval
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Last edited by Vlad; 12-18-2013 at 10:37 AM.
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