Welcome to the North American Subaru Impreza Owners Club Monday December 6, 2021
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.

* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 07-24-2012, 08:09 PM   #1
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG

Default EJ207 Info

So, I decided to put together some information about the EJ207.

This is not an FAQ for the EJ207 thread, but a collection of info that I have, which will allow those that are interested in these awesome engines to be informed more efficiently and not to have to go and re-ask the same questions in the said thread over and over again.

My style has been to clearly differentiate what I hold as fact (supported by backup) from what I have seen others post.
I will point out facts and mention some of the more interesting things that I've seen people post, again describing them as such.

What is an EJ207?

It is an engine that has been in production (wikipedia) since 1999.
It is still in production today and used for Sti and Sti Spec C cars for the Japanese market.

In time, this engine has equipped Subaru Impreza Sti cars in many countries, in Asia, in Europe, in Australia and New Zealand and maybe in South Africa.

It was never made available for the US market.

It is considered a 2.0 (1994 cubical cm) and has the following main measurements (factory brochure):

BorexStroke 3.62"x2.95"
Compression ratio 8.0 +_0.2

It is semi-closed deck, since the GDB Rev A (V7)
To be noted is that the latest EJ207 for Spec C models has a configuration of sleeve support that can be called better than semi-closed deck.
Some versions have had forged pistons and some have had cast pistons.
Some versions have had equal length headers, most of these with twinscroll. The differences will be reviewed below.

Why was the EJ207 engine not made available for the US market?

In 2003, Mitsubishi created a site with a countdown clock for their upcoming Lancer Evolution launching for the US market.
Subaru was at the time a competitor of Mitsubishi in the WRC and had similar vehicles in their line-up for sales.
Both companies were emphasising sportiness, handling and AWD.

Subaru wanted to create a vehicle that would upstage the Lancer Evolution. The terms of the upstaging were never "which could be modded to produce more HP", but "which is more enjoyable stock".
Subaru may have felt at the time that the 2.5 provides more torque and more HP than the Lancer and that at the time, it was showcasing quite a number of technologies and gadgets making the EJ257 equipped Sti more desirable/enjoyable than the Lancer.

Brief history of the EJ207

Begins in '98 with open deck and coil pack over manifold. Starts to be semi open deck with the V7 (GDB Rev A)
The subject of AVCS for early EJ207 has been debated in the past on this board.
With the appearance of the "New Age" Impreza, Subaru dropped the "Version" designation for the Impreza Sti, they differentiate the Sti by the factory designation "revision" A-G.
The talk of versions, which continues, is only a fan-club talk and we are trying to put some order into what we are describing:

Factory revisions A and B, amounting from 02/01/2000 to 10/31/2002, are called V7
Factory revisions C and D, amounting from 09/01/'02 to 05/31/'04, are called V8
Factory revisions E, F, G amounting from 03/01/'04 to 04/30/'07, are called V9

GRB bodystyle EJ207 are called V10.

As information, UK guys call a revision F and G a V10 and I think I've seen Australians call a rev F V10 and a rev G V11.
Both UK and AUS, due to being RHD, are better environments to have complete JDM cars on the street and under my opinion, there are a lot more of the complete cars on the road, than there are in the US.

Once you discuss complete cars, it becomes useful to have a conversation based on factory code number (It's the code that begins with GDB) and it can be useful to discuss V10 and V11 in GDB. However, in US, with only having engine, or only engine and transmission, there will be too few differences between a rev E, F, and G and it is suitable to call all of these a V9.

Also, discussing code numbers does not seem to be productive, when the engines of the two codes are actually identical and the difference between the two codes is a set of stickers that one car had and one did not have. If you will never see the donor car, it's a waste of time, I think.

I will focus this information on engines that start with V7.

The Gentleman's Agreement (jishu-kisei)

Wikipedia/Theory: Sometime in 1988 there has been a meeting between the top executives in the Japanese automobile manufacturing industry, regarding the production of cars for usage in the Japanese Domestic Market.
At this meeting, a more or less verbal agreement had been reached, to the effect that no Japanese maker will make available for the domestic market a vehicle with an output higher than 280 HP (crank).

Now, understand that the definition of the HP differs from US to Japan to EU, so you will see numbers anywhere from 280 to 275, depends on who's horses we're counting.

As time went by, nobody wanted to be second in domestic car magazine reviews, so rumor had it that all makers continued to advertise 280 but beefed up the power significantly....

The agreement never was intended to cover one-off vehicles or limited series, therefore the S 202, 203, 204 were advertised always at full potential. Also, I have never seen anything suggesting that the torque was going to also be limited, so the advertised torque could have been realistic.

The agreement was said to have been widely considered invalidated in 2004, so it is an interesting exercise to locate factory specs for a 2006-2007 Sti and compare them with earlier advertisements.
The importance of the Agreement is going to become clear when I will start to list advertised engine output below..

Involvement in Motorsports
According to Wikipedia, the Rally engines were develloped beginning, at the base, with an EJ207. Of course, a rally engine is a very-very expensive engine, well beyond the resources of .. your common guy.

Why would I want an EJ207 in my car, what can it do for me?

What has been said about the EJ207 is that is the genuinely "under-rated Japanese engine", maybe due to the Gentleman's agreement, they were laying the hardware foundation to keep quietly increasing the power every year, to stay ahead of the competition.

Basically, this is best suited for someone that does have a relatively tight budget and wants to avoid the constant horror stories about ringlands of the EJ257, the constant horror stories about spun bearings of the EJ205 and the constant sories about lower-end-power built engines still needing refresh/rebuilds every so often.
My personal opinion is that a built EJ207 is not any more reliable than a built EJ257, I think this reliabillity is only for the factory put together engines.

Basically, the hope with an EJ207 is that you reach a power level that allows you to enjoy your car and still run without a rebuild 100K miles or maybe even more.
The power levels will differ based on driving style, quality of mods and quality of tune.

Special versions of the EJ207 engine

Type RA Sti Rev A (Version 7 engines)
People usually refer to these wrongly as V7 Spec C. Spec C did not exist as a designation right away, when the bugeye Sti began.
These engines were the only ones to have different and bigger ports on the inlet ports of the heads. The ports are bigger due to extra 0.5mm smoothing of the port radius on the narrow side of the "pear" shape. Also, these had the shoulder removed by the valve guide in the casting of the head, at the intake port.


All the following years Sti and Spec C have the same size ports on the intake.

Sti Spec C Type RA Rev B (Version 7 engines)
These engines were the only ones to receive dedicated internal engine parts in GDB. They got only for '02 special springs and special cams. The cams were then used on all Sti for the next year. Different turbo, with roller bearings, VF34, the ROM reflected this.

To recap: Rev A, is not called Spec C yet, gets slightly bigger ports. Rev B, is called Spec C type RA, gets run of the mill JDM big ports, but gets upgraded cams and springs.

V8 Spec C engines
The V8 Spec C received a different turbo, the VF36, with roller bearings. Some sources indicate it has titanium aluminide turbine and shaft. I tried to check mine with a magnet, but it's not a good test unless you remove the housings, which is not that easy on VF ballbearing turbos.
There is an intercooler autowash feature that can be activated from the ECU that stabilizes the intake temperature, using tables in the ECU.
The intercooler received a redesign, compared with a V7.
There are two possible spec C engines, with all years: there is a model with A/C and one without. The one without gets a different front belt cover, metal. The Type RA designation that some Spec C carry may or may not be related to this.

V9 Spec C engines
The V9 Spec C also received the VF36 turbo. An optional package became available for the Spec C engines, for Air-to-Air oil cooler. I like to call it oil radiator, to differenciate it easier from oil cooler. The oil radiator package, replaces the oil cooler with an oil manifold, that then is connected via rubber couplers (no ordinary rubber), to a metal oil riser that takes the oil behind the right side headlight and in front of the coolant radiator where some more rubber couplers connect it to the oil radiator.
The oil manifold is thermostatic and there is a group N option for braided hoses adaptor.
There is an intercooler autowash feature that can be activated from the ECU that stabilizes the intake temperature, using tables in the ECU. This engine received a more advanced intercooler than the V8, but still not so advanced as a GRB Sti intercooler.

S202 Engines
I found the old S202 press release. The turbo was a VF34, like the Spec C. It got OEM the expensive sti turbo inlet. It did not get an immobilizer. It did not receive separate assembly line ballancing. The ROM reflects settings different from even the Spec C. The engine speed limit is still 8000 rpm.
This engine received a separate oil cooler package with braided stainless hoses. There was no version for the Spec C V7 for oil radiator. Some comments about equal length headers did not check out.

S203-S204, RA-R Engines
These engines received the VF42 turbo. I have seen one picture of this turbo with a compressor wheel speed sensor port. All sources indicate this turbo as having titanium aluminide turbine and shaft, with 9 turbine blades.
If Ti-Al has a affinity for bright-red oxidation, then this can confirm that this is the material for the VF42. VF36 also does bright red oxidation.
The ROM is different for these, notable the AVCS more aggressive and timing map different.
They came from the factory with oil radiator, the same one as the Spec C.
The S204 had immobilizer for sure. The S203 may have had it too.
I have seen no evidence of hand porting of the inlets of the heads on these.
The internals have been separately ballanced for the S203 (official info), The internals have been select weight ballanced and crank manually ballanced for S204 (official info).
The RA-R was not ballanced (official info).
It has been said that the ballanced engines have marks by the flywheel.
The Ra-R had no marks.


Below S204 Flywheel vs USDM, by Fierysun, owner of this rare engine.

The speed limit for these engines is still 8000 rpm.

Other special engines
There could also be a yet different category of engines, that the factory provides for privateers. These are not the super-expensive Rally engines, nor the Prodrive engines. You can get an idea by looking at the WRSpares inventory.
I arbitrarily have decided to call these "inbetween engines" "group N engines".
These may sometimes show up in a batch of imported used engines and some of the guys that look into these engines see features that they then extrapolate to the whole line of JDM Sti engines.

Differences between standard Sti engines V7-V9

Internal differences

I think the best available info about differences in V7-V9 and Spec C versions can be found in the work of Jeff Sponaugle, a compiled huge list of all part numbers of all JDM and export Ej207.

It is to be noted that the models for '05 are wrong in that they should be designated (By Ex.:GDAD4HD should read GDAE4HD). Rev E has E in 4th position. This will not affect anything else.
In short:

V7 pistons are different, universally said is that these are forged, evidence below.
I found information at the APS site, comparing a USDM Sti piston with what had been the standard before it, a forged piston.

Forged piston is 12 grams lighter, but the pin is 10 grams heavier, with most weight distributed around the centre.

V8+ pistons are cast, hypereuthectic.
Here is a link to a photo of part number 12006AC430, the piston for V8-9


In the link, at the sides of the piston, by the wrist pin bore there are casting marks where the forged pistons are smooth.

V8 and V9 receive updated block, and crankshaft and heads headgaskets. The crankshaft is said to be doublecrossdrilled.

V9 receive updated rods, these rods are backward compatible, are the same part number as the USDM rods.

V8 use the V7 spec C cam, without those V7 Spec C springs

V9 get updated cam

Overall, V9 is a completely different engine from the V7, different part numbers for all main parts, except valve springs. Those they only briefly tried to upgrade back in '02.

Important Note
EJ207 for other than JDM, continued with forged pistons beyond V7. It was discontinued with the arrival of the EJ255-257 in 2006. The V8 export (UK, AUS, EU, SA), was likely not twinscroll, different than JDM turbo.

Other Differences

V7 are single scroll, AVCS, throttle by cable, topfeed injectors, engines.
The TGV are deleted from the factory. The factory deletion is incomplete, even on the Spec C and even on the Type RA.
The exhaust is compatible all the way to the downpipe to the USDM WRX/Sti. Oxygen sensor same as USDM EJ205
The oil pan is like the USDM WRX 2.0
The Turbo is the VF30.
The ECU has the same number and shape harness plugs as the USDM WRX 2.0.
No immobilizer.
The engine speed is limited from the factory at 8000rpm

V8, 9 are twinscroll, AVCS, throttle by cable, topfeed injectors, engines.
There are no TGV's, the intake manifold is one piece.
The spark plugs are specified one step colder, compared with other Sti.
The exhaust is completely different/incompatible with the USDM WRX/Sti, all the way from the header to the downpipe. It can be replaced by a USDM exhaust, the USDM does bolt up to the block.
The oil pan is like the USDM Sti.
The turbo is a VF37.
The ECU has the same number and shape harness plugs as the USDM WRX 2.0
There is no immobilizer for V8 and for some V9.
The V9 known so far to not have immobilizer have been early V9 Spec C (revision E engines).
The engine speed is limited from the factory at 8000 rpm
When compared with the USDM A/C Compressor, the JDM Sti is of a different part number and smaller in size. It is possible that the losses while using it are smaller.
Many have an additional intake air temperature sensor by the throttle body. It's function has been discussed but not completely clarified.
The power steering pump is different. The JDM cars included some Spec C with 13:1 steering rack. The pump remained the same, so it is designed to handle a fast rack.
The com protocol is not canbus for any of these.
Some of the Sti engines don't come with provision for cruise control. It's next to impossible to tell which had it.
The ROM settings are quite different from a V7.
The turbo inlet has one less connection in it and most likely is of a larger diameter than the USDM, from the factory.
The front Oxygen sensor has been relocated after the turbo, in the downpipe. Different part number 22641AA042.

Advertised Engine Output

Sti 2002 (internet source)
Horsepower (PS/rpm) 280 / 6000 [206kW/rpm]
Torque 394N.m/rpm(Kgm/rpm) 40.2 / 3500

Meaning: 290.5 ftlb @ 3500 RPM, 276.1 BHP
Comments: the single scroll provides the fastest spool, stock.

Sti Type Ra Spec C 2002 (from press release)
Max. torque output 384 Nm
Max. Power "Enhanced power"

Meaning: 283.4 ftlb
Comments: there was really no figure on power and neither on the RPM at which the torque was reached. This was with those special valve springs too.

2004 Sti Spec C (internet source)
Max. Power 205.8 kw / 276 bhp @ 6400 rpm
Max torque 412 nm / 303.9 ft lbs @ 4400 rpm

Meaning: 303.9 ftlb @ 4400 , 276 BHP
Comments: the twinscroll arrives, bringing higher torque, but slowing spool down. I have to revisit my stock JDM ROM collection, but I think that the boost went up a bit like 1 PSI.

2005 Sti (internet source)
Horsepower (PS/rpm) 280 / 6400 [206kW/rpm]
Torque 422N.m/rpm(Kgm/rpm) 43.0 / 4400

Meaning: 311.2 ftlb @ 4400 , 276.1 BHP
Comments: V9 arrives, with the completion of engine internals updates and they are confident to increase the torque at this point.

2005 Sti Spec C (internet source)
Horsepower (PS/rpm) 280 / 6400 [206kW/rpm]
Torque 422N.m/rpm(Kgm/rpm) 43.0 / 4400

Meaning: 311.2 ftlb @ 4400, 276.1 BHP
Comments: The ROM shows an earlier spool designed for the Spec C and a higher boost designed for the Sti, the maximum numbers don't tell the whole story.

2007 Sti Spec C (internet source)
Max. Power 205.8 kw / 276 bhp @ 6400 rpm
Max Torque 422 nm / 311.3 ft lbs @ 4400 rpm

Meaning: 311.3 ftlb @ 4400, 276 BHP
Comments: no more changes in performance at this point. This is another reason for which this is also called a V9.

S202 (from official page)
Max. Output (net) 235 kW (320 ps) / 6400 rpm
Max. Torque (net) 384 Nm (39.2 kgm) / 4400 rpm

Meaning: 283.2 ftlb @ 4400, 315.6 BHP
Comments: the RPM at which this is reached suggests the equal length headers.

Max. Output (net) 235 kW (320 ps) / 6400 rpm
Max. Torque (net) 422 Nm (43.0 kgm) / 4400 rpm

Meaning: 311.2 ftlb @ 4400, 315.6 BHP
Comments: Twinscroll arrives to the S engines. Increased torque is reached.

Max. Output (net) 235 kW (320 ps) / 6400 rpm
Max. Torque (net) 432 Nm (44.0 kgm) / 4400 rpm

Meaning: 318.6 ftlb @ 4400, 315.6 BHP
Comments: V9 arrives, with internals updates completed, they are confident to reach a higher torque.

Type RA-R
Max. Output (net) 235 kW (320 ps) / 6400 rpm
Max. Torque (net) 432 Nm (44.0 kgm) / 4400 rpm

Meaning: 318.6 ftlb @ 4400, 315.6 BHP
Comments: while this engine has the same performance as an S204, the car is faster, because it also combines Spec C lightness into the mix, something that the S cars did not have. The difference in weight of the two cars is signifficant.
* Registered users of the site do not see these ads.

Last edited by Vlad; 01-21-2020 at 09:26 PM.
Vlad is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-24-2012, 08:09 PM   #2
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


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.

For state Inspection, it 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 http://www.importtuner.com/tech/0311it_sti_conversion/
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.

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 : ***12510;***12491;***12517;***12450;***12523;***36554;
AT : ***12458;***12540;***12488;***12510;***12481;***12483;***12463;***36554;
STI spec C 34B19L
1.5 55D23L
2.0 MT***36554;55D23L
2.0 AT***36554;65D23L
***12473;***12496;***12523;***12514;***12540;***12479;***12540;***12458;***12452;***12523; SM 5W-30
***12473;***12496;***12523;***12514;***12540;***12479;***12540;***12458;***12452;***12523; SM 0W-20
***12473;***12496;***12523;***12514;***12540;***12479;***12540;***12458;***12452;***12523; SL 5W-30
***12456;***12523;***12501; 10W-50 ***12524;***65381;***12503;***12524;***12452;***12450;***12540;***12489;10W-50
1.5i***12289;1.5R ***32004;4.0 ***32004;4.2
WRX AT***36554;***32004;4.0 ***32004;4.2
WRX MT***36554;***32004;4.0 ***32004;4.3
STI***12289;STI spec C ***32004;4.0 ***32004;4.3
STI spec C***31354;***20919;***12458;***12452;***12523;
***32004;4.0 ***32004;4.6
10,000 km***12372;***12392;***12289;***12414;***12383;***12399;12***12363;***26376;***12372;***12392;
***20132;***25563;***26178;***26399;10,000 km***12372;***12392;
1.5R***20197;***22806;60,000 km***12372;***12392;
1.5R 100,000 km***12372;***12392;
10 kgf***65289;***12398;***21147;***12391;***25276;***12375;***12383;***12392;***12365;
9***65374;11 mm
10 kgf***65289;***12398;***21147;***12391;***25276;***12375;***12383;***12392;***12365;
9***65374;10 mm
1.5i ***8251;PFR5B-11 NGK 1.0***65374;1.1 mm
1.5R ***8251;ILFR6B NGK 0.7***65374;0.8 mm
WRX ***8251;PFR6G NGK 0.7***65374;0.8 mm
STI***12289;STI spec C ***8251;PFR7G NGK 0.7***65374;0.8 mm
***20132;***25563;***26178;***26399;100,000 km***65288;***30333;***37329;***12503;***12521;***12464;***20351;***29992;***65289;
***36938;***12403;***25351;***12391;***25276;***12375;***12390;1***65374;3 mm
***32004;300N***65288;***32004;30 kgf***65289;***12398;***21147;
85 mm***20197;***19978;
1.5 ***36554;***32004;10***65374;20 mm
2.0 ***36554;***32004;3***65374;13 mm
***8213;***8213;***8213; 80 mm***20197;***19978;
***32004;200N***65288;***32004;20 kgf***65289;***12398;***21147;
7***65374;8 ***12494;***12483;***12481;
STI spec C 3.0
1.5i***12289;1.5R ***28961;***37467;***12524;***12462;***12517;***12521;***12540;***12460;***12477;***12522;***12531;***20351;***29992;***32004;50
WRX***12289;STI ***28961;***37467;***12503;***12524;***12511;***12450;***12512;***12460;***12477;***12522;***12531;***20351;***29992;***32004;60
STI spec C ***28961;***37467;***12503;***12524;***12511;***12450;***12512;***12460;***12477;***12522;***12531;***20351;***29992;***32004;50
***20132;***25563;***26178;***26399;50,000 km***12372;***12392;

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 ***8251; PFR5B-11 NGK 1.0 ~ 1.1 mm
1.5R ***8251; ILFR6B NGK 0.7 ~ 0.8 mm
WRX ***8251; PFR6G NGK 0.7 ~ 0.8 mm
STI, STI spec C ***8251; 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

Some part numbers when you initially replace the timing belt:
13073AA142 (two of these)
Idler bolt for the superseded one 800110360, you will pull a single bearing and install a double bearing idler, the JDM part number changed. You may not need this bolt, the existing one may work.
Spec C water pump replacement
gasket 21114AA051
left side timing cover, always comes damaged
Sti pink timing belt

Last edited by Vlad; 05-27-2018 at 11:20 AM.
Vlad is offline   Reply With Quote
Old 07-24-2012, 08:10 PM   #3
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


How to ID your EJ207

The easiest way, is to look for a white sticker, on the bottom of the left timing cover.
Then take the number there and compare it with the table that I posted the link to above, then find out what engine you have.

What if the sticker is missing, or you suspect it's faked ?

You have to think for a minute. If somebody is going to fake the sticker, what would be the purpose of doing that?
Financial, to charge more money, to make the engine more desirable.

So then, there could be suspicion that an engine is not really a Spec C.
But now we know what a spec C should really be...

A spec C is for most of the part an Sti engine with a few add-on parts. If the add-on parts are there, then it's a Spec C engine, it's as simple as that. There would not be any point in adding all the spec C parts to an Sti engine, in order to fake it.
In sum: If this is not a V7 spec C, then if it has the VF36, if the ECU checks out to be a Spec C code number, if the ROM checks out to be a Spec C ROM, if it has no cruise control, then it's a spec C..
It could be a Spec C with the oil radiator option or with the no A/C as well.
Manifold for oil above the filter, instead of cooler, for the oil radiator option..


If it's a V7 spec C, you would have to acquire the knowledge of reading the codes etched on the camshafts, then pull the valve covers and ID the camshafts.

Here I will ad camshaft info.
Below for now are some specs for v8+ cams

Here is information about the clearance to deck, the distance from the top of the piston at TDC and the gasket plane, as well as compressed gasket thickness:
For V7 RA clearance is -1.5 +/- 0.5mm
For V7 Spec C clearance is -1.5 +/- 0.15mm, headgasket crushed 0.7 +/-0.2mm
For V9 clearance is -1.5 +/- 0.15mm, headgasket crushed thickness is 0.7 +/- 0.2mm
For V10, clearance is -1.5 +0.15mm to -1.5 -0.30mm, headgasket crushed thickness is 0.7 +/- 0.2mm

If it's an S engine, it has been said that there are clear maks of it having been ballanced, visible by the flywheel. The ECU carries a special sticker with a serial number, maybe that can be traced to one of the numbers on the block.. Not to mention that if the VF42 is present, odds are good that it's genuine.

Some Spec C engines do not come with an A/C compressor. This was not an option package, it was a spec C model. For a while people believed that a Spec C did not have A/C and that a Spec C type RA did have it. This is not the case, both cars were called Spec C type Ra, or in Subaru designaton RASC.
The factory created a dedicated metal belt cover, that replaces the plastic belt cover, for this engine.


Typical tune up and replacement parts

I'm not going to go into what some people have substituted and the engine still ran. For that it's still best to ask on the EJ207 thread. This is a decision every person has to make, based on their budget and ideas.

There are a very large, majority number of parts that are the same between USDM and JDM.
There are a small number of parts that are speciffic to this engine.
Those can be bought through IAP or Japanparts.

Spark plugs

Specified in the owner's manual are the NGK PFR7G with 0.7-0.8mm gap
There are some NGK that have a similar part number, but wrong gap. It has been said that attempting to re-gap these plugs results in having misfires.
The iridium equivalent of these plugs is available, it's the best choice. Get the BKR7EIX, or BKR7EIX-P, but not BKR7EIX-11.
I have seen specified for a V9 as racing use PFR8G, in the Sti catalog.

Head Gaskets
The V7 gets 11044AA482/483, the same as an '02 USDM WRX EJ205.

The V8-9 gets 11044AA651, not the same with any USDM gasket.

Timing belt

The timing belt has a different part number than any belt sold in US. The replacement interval is at 62K miles. Coincidentally, the reinforced Sti timing belt sold here in US as the Sti pink belt, also has the replacement at 62K miles and the same part number for this belt is also specified for the EJ207.
I think that there is a mandated minimum timing belt replacement interval and that softer belts meet that, for USDM.
For higher rpm you need a more rigid belt, which in turn requires replacement more often.
So I reccomend the Sti pink belt, because by the time you buy the OEM belt from Japanparts, if you really shop the pink belt well, the prices will be similar. For probably $20 less, you can also get the reinforced belt from a different supplier: Gates, by example.
When you replace the belt, replace also the silver sticker on the right top side of the timing cover. That keeps track of belt replacements.

Water pump
If you have the oil radiator option on a Spec C engine, you need to use a 2008+ WRX (non-sti) water pump, it's the proper part number.
For the regular setup, a 2005 USDM water pump is good for V8 and 9.
V7 has a part number not found in US. Check the thread for substitutions.

Accessory belts
I just took of mine, walked to the parts counter at the dealer and bought identical replacements. If you have the no A/C Spec C engine, this may be a bit different.

It's the same part number as for the USDM GDB WRX & STI

Coil Packs
V7 get the USDM WRX 2.0 coil packs for '02, the rest get the '05 WRX ones.

Twinscroll wastegate actuator
The stock actuator is rated at 12.3 PSI.

I will expand this later
If you finished the swap, turn the key and before trying to start, the check engine light does not come up, the fuel pump does not prime, you may have an immobilized ECU

Final notes
Once the swap is in, get yourself familiar with logging and start checking the parameters of your engine BEFORE you start driving around.
Odds are, you will need a tune to get your engine within safety, to protect your investment.

As far as the fueling, Subaru decided to settle the urban legend of the "JDM Super-fuel", by printing in the 2015 BRZ Owner's manual that the JDM Octane rating of 98 RON is one and the same with the USDM octane rating of 93 AKI.

This has been a looong-running urban legend and it took a lot of time posting, researching, to bring this to light.

It is important to note that tuning wise, that which applies to the EJ257, timing-wise, is not one and the same with an EJ207.
This can be easily seen, by comparing the timing tables of a JDM EJ257 (as seen in the Sti A-line), with the JDM EJ207 timing table.
The 207 needs its timing, to shine.
Adjustments need to be done based on your mods and surely if you can't fuel 93 AKI.
If you don't know much about tuning and wish to understand what your tuner did to the timing of your EJ207, look at the torque curve, on the dyno.

Take a 2004 V8 Spec C engine:
From the factory it's rated at 304 ftlb. Now, we know that the torque rating is not crank/wheels, but only one value, corrected to the engine.
Say that your dyno results are 320WHP but 280 Ftlb.
This means that your tuner gave you less torque than the factory, they tuned your engine down. If the fuel quality is the problem (you can't fuel 93 AKI), then this is the explanation.
A timing-rich tune often yields dyno results where the torque number is higher than the WHP number. This is how you ID your tune.

Some tuners will give JDM fuel rating as a reason for removing the timing from your engine, then will bring up reliability concerns.

The overwhelming tuning method is the boost based tuning.
The factory did a timing based tuning and many tuners remove this.
Building on top of the factory tuning is also an idea, something I always had an interest in and worked on.

Here is a link to the 207 owners thread.

Here is a link to the twinscroll stock location upgrade thread.

Newer Twinscroll turbos from GRB body '08+: VF49, 53, 56 are backwards compatible with V8, 9 engines

Last edited by Vlad; 02-11-2018 at 08:53 AM.
Vlad is offline   Reply With Quote
Old 07-24-2012, 08:14 PM   #4
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG



The early GRB EJ207

As the GRB bodystyle started for the JDM, Subaru did not yet have a Spec C model. They quickly started an A-line Sti, equipped with an EJ257 and automatic transmission (different than the USDM EJ255 GRB one) and used an EJ207 converted to throttle by wire, canbus, no intercooler autospray, immobilized, dual AVCS.
All GRB EJ207 have the dark blue injectors, replacing the GDB pinks.
The turbo is a VF49, twinscroll. The intake manifold has functional TGV's. The engine speed limit is 8000 rpm

It is possible, but not confirmed yet, that for these engines, the castings were the thick liner, desirable ones, described below in detail, under "spec C".
The part number for the kit of : block half-castings, castings bolts, castings plugs is:
1008AB210. This is the same part number as for the later Spec C engines, suggesting that while the long block is different, the castings are the same, you'd still get the thick liners.

I believe that these were the Rev A and B
The codes of these engines are

The factory notes for these are two, the first is "for EJ207", the second is "for Sti".

So in a confusing way, the first of these engines, went into a car called "EJ207". My opinion is that this refers to the factory prototype, it could be ANY chassis.

The Sti in Rev A was not yet a Spec C

The Spec C EJ207

Sobaru finally rolls out the Spec C. They were definitely putting together the base for a strong engine for this particular EJ207.
These are dual AVCS, topfeed injectors (they switched to dark blue ones), with functional TGV's, canbus, throttle by wire, immobilized.
These came, at least in the beginning, still with the VF49, then the VF53. Then the VF56 for the R205 and then for the S206.
This engine was homologated for Group N.
The intake ports in the heads are much bigger than anything before, by as much as 2 milimeters. The exhaust ports are larger by 0.7mm, but the inner diameter of the exhaust manifold is unchanged.
The block for the Spec C is a thick casting, reinforced block, I call it a 3/4 closed deck.

The total thickness of the liner and liner support, measured at the headgasket seating area is:
EJ257 7.7 mm
EJ207 GDB 9.6mm
EJ207 GRB 13.2mm
Here is a photo:


I believe that these were the revision B Spec C engines.
the codes for these are:

The factory notes for these two are "for Spec C" and then you have couple option packages.

An important note is that the option packages marked OPC are starting to show up again, with the beginning of the Spec C.
I never really decoded the OPC yet, but within OPC 91-93, in GDB, you had oil radiator, no AC, lightweight battery and maybe small windshield washer tank.
So now OPC91-94 are showing up, hinting to a possible GRB Spec C with no AC and maybe with oil radiator.
A new OPC 98 appears..

How to ID your GRB EJ207

This becomes a very important question, if the early GRB EJ207 can be different..
I have partial information available, from the work of dr20t (Mick).
This partial information is important because it points towards the spec C engine.
As in the photo below, it is marked with B25C. Don't forget that there WERE JDM EJ257 Sti, they can also be marked B25C. However, the EJ20 sqare casting mark, singles thisone out as EJ207.


Mick noted that the extra thickness of the liners (and maybe of sleeves too?) is obtained from a casting similar to an EJ257, but with thicker liners, to account for the reduced displacement (and cylinder diameter) pf the EJ207.
Apparently, the coolant jacket holes in the headgasket, line up with those in an EJ257 headgasket.

The pistons are cast, from all the info available at this time.

These were provided by Mick.

There is still a significant amount of TDC to deck clearance with these. The clearance to deck is the same as a V8-V9, the compression ratio with a hybrid based on heads from V8-9 would not change.
Headgaskets are particular to these.
The part number for the kit of : block half-castings, castings bolts, castings plugs is:

Swapping the GRB EJ207

Swapping into a GDB Body
The GRB needs its ECU to work properly. This time, the discrepancy in range between AVCS and other parameters is larger.
The GRB both in US and JDM can only be CANBUS.
CANBUS is vaguely similar to Ethernet.
So your GBD ECU does not have the "network switch" installed, hardware is missing. It could not control a GRB engine.

Caution: the following is theory only, nobody has tried this yet.

-You could use your GDB JDM EJ207 ECU

-You could use your GDB EJ207 heads and manifold, with all associated sensors.

-You would in this case use the GRB EJ207 headgaskets and bolts, the compression ratio will not change.

-There are 3 sensors that normally would be located on the GRB block and their compatibility has to be looked at:
The knock sensor, water temp sensor and the Crank position sensor. The information available suggests that these should work even from GDB.
In fact, K2Kevin posted in this thread that the 32bit crank sensor is the same as the 16 bit crank sensor and that the only other 32bit conversion was to change the plug style for the temperature sensor, to splice a different style plug into the engine harness.
This has been done in reverse (16 bit sensor substituted by 32 bit sensor), by Kpluiten and K2Kevin, in their projects of converting a 16bit EJ207 to a 32 bit EJ207.

-You would use GDB EJ207 spark plugs and coil packs that you already have.

This combo should in theory be more sturdy than a regular GDB EJ207, due to the thicker liners and flow air the same way a GDB 207 would.

From the latest research and clearance to deck info above, the compression ratio of the hybrid will not change.

Swapping into a GRB USDM body

I am seeing two swaps GRB into GRB with one other possibly done with the owner unwilling to post or share any info. I believe that this third and oldest one is a full and complete swap, including wiring, etc, therefore not that interesting or important.

Once again, here is my theory:

Since CANBUS cand be vaguely compared with Ethernet, each ethernet device must have a switch and a software driver.
When you get a JDM ECU, the first step is going to be to get the immobilizer to allow the ECU to start the car.

For the GRB, the latest information collected from Mick and Dave is that you need as a matching kit: the Cluster, Body control unit, ECU, keys and immobilizer unit.
The GRB would already have the antenna built into the ring.
This may sound like a lot, but many convert their clusters anyway

Once you start the car, the problems you may be facing will have to do with the ECU seeing on the network devices for which it has no drivers.
By example: USDM ABS.

The only thing i happen to know is that German VW implementation of CANBUS uses the VAG software to install drivers each time you replace a sensor.
So maybe there is a driver installation device, like a Subaru laptop and there are drivers that they download from a database.

End of theory, beginning of collected data.

One fo the other two swaps mentioned above, resulted into the engine started but idrive and ABS/VDC non functional. The owner believes that swapping a JDM ABS unit may solve that problem.
I have a different theory:
A board member has tried to implement a quick steering rack, made by Qrack in a GRB Sti, the ECU of that car has then disabled the VDC/ABS, due to unmatching output from the steering angle sensor.
A Spec C ECU would expect to find a 13:1 steering rack, and if it finds a 15:1 standard Sti rack, it will then disable the ABS/VDC probably (this is a theory). The solution would be to get a Qrack.

Last edited by Vlad; 02-11-2018 at 09:08 AM.
Vlad is offline   Reply With Quote
Old 07-24-2012, 08:46 PM   #5
Scooby Specialist
Member#: 224785
Join Date: Sep 2009
Chapter/Region: MWSOC
Location: neenah
2005 wrx-jdm207
i went black...


THANK YOU, had enough of the same questions asked again and again in the ej207 thread.
WhiteBgeye02 is offline   Reply With Quote
Old 07-24-2012, 09:15 PM   #6
Scooby Specialist
Member#: 175334
Join Date: Mar 2008
Chapter/Region: TXIC
Location: Dallas, TX
2003 Impreza WRX
JDM v8 EJ207 WRB


Kudos to you Vlad for putting together such a useful compendium of EJ207 knowledge! Perfect supplement to the already existing Mega Thread that so many of us have subscribed to.
Torquey is offline   Reply With Quote
Old 07-24-2012, 09:47 PM   #7
Scooby Specialist
Member#: 114208
Join Date: May 2006
Chapter/Region: BAIC
Location: EWWW, CA
2007 MINI Cooper S
Grumpy Old Man Tan (SSM)


Cool, good stuff. Subscribed for the later updates
darthalal is offline   Reply With Quote
Old 07-24-2012, 11:46 PM   #8
Scooby Newbie
Member#: 289486
Join Date: Jul 2011
Chapter/Region: NWIC
Location: Yakima
03 WRX



Edit: Thank you sir.

Last edited by Gam30vR; 07-25-2012 at 01:33 AM.
Gam30vR is offline   Reply With Quote
Old 07-25-2012, 01:00 AM   #9
Scooby Specialist
Member#: 123625
Join Date: Aug 2006
Chapter/Region: NESIC
Location: Dover, NH
2015 WRX
Galaxy Blue


Also subscribed, This will come in useful when I buy a 207. Thanks vlad.
2gnt2wrx is offline   Reply With Quote
Old 07-28-2012, 12:37 AM   #10
hybrid gti 2
Scooby Guru
Member#: 67004
Join Date: Jul 2004
Chapter/Region: SCIC
Location: (818) 300k+ ej205 ppg 5mt
02 vf30 pnp wagon
silver and cf

Thumbs up

This should be a sticky or part of a sticky.

Thank you Vlad
hybrid gti 2 is offline   Reply With Quote
Old 07-31-2012, 10:53 AM   #11
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


Thanks, guys, this is complete for now..
Vlad is offline   Reply With Quote
Old 07-31-2012, 11:07 AM   #12
Scooby Specialist
Member#: 191495
Join Date: Oct 2008
Chapter/Region: NESIC
Location: Lowell MA
'05 WRB GTX3071R


Vlad is the man
todeswalzer is offline   Reply With Quote
Old 07-31-2012, 04:40 PM   #13
Scooby Guru
Member#: 82745
Join Date: Mar 2005
Chapter/Region: SCIC
Location: So Cal
2005 Subaru STI
2003 EJ207 S204 Wagon


Nicely done Vlad.
Fierysun is offline   Reply With Quote
Old 07-31-2012, 05:30 PM   #14
Scooby Specialist
Member#: 54060
Join Date: Feb 2004
Chapter/Region: Tri-State
Location: N Jersey
Now: 16 FXT/04v8 207
Then:JRTuned fastest td04


Very nice, thanks!
OppositeLock is offline   Reply With Quote
Old 07-31-2012, 05:49 PM   #15
Scooby Specialist
Member#: 151739
Join Date: Jun 2007
Chapter/Region: NESIC
Location: Lakeville, MA

Great read, thanks!
DNut is offline   Reply With Quote
Old 08-13-2012, 08:44 AM   #16
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


Thanks guys, it seems this is working, because there have not been anymore recurring "where do I start this" type questions in the EJ207 Owners thread.
I've applied for a sticky for this, let's see what happens..
Vlad is offline   Reply With Quote
Old 08-13-2012, 09:31 AM   #17
Scooby Specialist
Member#: 57287
Join Date: Mar 2004
Chapter/Region: MWSOC
Location: Kalamazoo, MI
2002 Bugeye STi


Great write up Vlad.
kayen is offline   Reply With Quote
Old 08-13-2012, 09:34 AM   #18
Scooby Specialist
Member#: 166427
Join Date: Dec 2007
Chapter/Region: South East
Location: boynton bch, fl
03 wrx


this is what im been looking for.
561wrx is offline   Reply With Quote
Old 08-13-2012, 09:49 PM   #19
Scooby Newbie
Member#: 255146
Join Date: Aug 2010
Chapter/Region: International
Location: Ashford,UK
2001 2002 WRX Wagon


JDM V7 STi has been equipped with VF30

JDM V7 Spec C Type RA has been equipped with VF34 as only one

Rev limit on the JDM STi V7/V8/V9 is 8250RPM

jura11 is offline   Reply With Quote
Old 08-13-2012, 10:27 PM   #20
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


Hi Jura,
You can find the Spec C Type RA under special versions. The two versions refers to engines, not turbos, fixed, thanks.

I compare the "regular" JDM Sti under "Differences V7-V9". It is there that the Vf30 is mentioned, under other differences. I will clarify that this refers to run-of-the-mill JDM Sti.

As far as the 8250 RPM limit, the ROM does not support that for any JDM Sti, V7-V10.
The limit in ROM for all these cars is at 8000 RPM.
Now, while the limitator kicks in, it is possible that a log could show slightly over 8000, however, what shows is not part of the RPM span that is intended for use, that is not sustained RPM.
Unless you have evidence to the contrary, please correct your information, the limit is 8000.

Last edited by Vlad; 10-17-2012 at 05:31 PM.
Vlad is offline   Reply With Quote
Old 08-14-2012, 01:37 PM   #21
Samurai Jack
Scooby Guru
Member#: 21145
Join Date: Jul 2002
Chapter/Region: NESIC
Location: Not in my own time
2002 Enemy of Aku


Fast forwarding to the end until I finish reading this thread

Nicely done and thanks for the work to put this together
Samurai Jack is offline   Reply With Quote
Old 09-17-2012, 08:28 PM   #22
Scooby Newbie
Member#: 234645
Join Date: Jan 2010
Chapter/Region: TXIC
Location: Houston, TX
2002 WRX Wagon
Midnight Black Pearl;


Vlad, thanks for the great info. After reading this a couple time I dont fully understand what i need to do with my ecu/ecu's. I would like to put a V8 into a 2002 wrx, keeping the 5spd. Can you clarify. I would like to have the avcs and the obd scanner to work. I am not a wiring wizard. What is the simplest way to do this.
BugEyeBetty is offline   Reply With Quote
Old 09-17-2012, 09:03 PM   #23
Scooby Guru
Member#: 46135
Join Date: Oct 2003
Chapter/Region: Tri-State
Location: NY
19 GLA45 AMG


The V8 engine that you buy should come with it's own V8 ECU. This will plug into the existing 2002 WRX harness.
Later, you can add the AVCS harness, the easiest way is by buying it from IAP.
Looking at the diagrams, some of the pins seem flopped for the JDM ons2.
But I am getting reports of form members being able to use obd2 scanners with the JDM ECU.

Edit: I revisited this issue with greater detail, OBDII scanners use ISO Protocols. These can differ in the pin that is needed for communication. SOme handheld scanners are multi-prtocol and can scan several pins, until they actually connect.
SOme otherones look just for the pin that has a different connection for the JDM.
Subaru uses a different protocol, the flashing and reflashing software all work, I think due to this: Ecutek, Ecuedit, Ecuflash, Romraider logger, Ecutek data monitor, Ecutek delta dash and road dyno, all work, with no repinning needed.

However, a state inspector computer could pull 3 different kinds of info that have to match: year, country and model.
So even if the state inspector computer can now communicate with the JDM ECU, they will expect to see: 2002, USA, WRX and they will see 2004 Japan Sti.
So getting the JDM ECU to do OBD2 is.... not that desirable...

Last edited by Vlad; 10-17-2012 at 08:40 AM.
Vlad is offline   Reply With Quote
Old 09-17-2012, 10:26 PM   #24
Scooby Specialist
Member#: 59837
Join Date: Apr 2004
Chapter/Region: SWIC
Location: Nor Cal
2004 Spec-C Type RA
What MAF? -Speed Density!


Some states OBD emissions just look for sensor status and not the model, year, ect. The JDM ecu will say that the various emissions sensors are OK when prompted by the emissions computers and therefor will pass without any issues.

I know this is the case for Arizona(passing with no issues) but I have heard some people on the east coast having trouble.
lukeskywrx is offline   Reply With Quote
Old 09-17-2012, 10:48 PM   #25
Scooby Newbie
Member#: 234645
Join Date: Jan 2010
Chapter/Region: TXIC
Location: Houston, TX
2002 WRX Wagon
Midnight Black Pearl;


Im in Texas. I will check into the obd scan. So, i can run the jdm ecu with my dash harness. The obd2 scanner will not work. If i need to.scan the ecu i will have to connect directly to it. If my state does check the engine year info when getting an inspection i can just unhook the jdm ecu and replace it with my usdm ecu. There shouldn't be any issues, just that my avcs will not work.
BugEyeBetty is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 05:06 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2021 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.