Thursday, August 16, 2012

Brembo GT Information Source, Part 8: Troubleshooting

Update 1
I think that my adjustable struts (Tokico D-specs), which allowed for flat stance braking, were not allowing enough weight transfer on the front wheels.
I've re-adjusted them a half turn softer, the car does some tilting under braking and I THINK i may have resolved this. I'll test some more when the weather gets better and post the results.

I'm at 5.5 turns of adjustment all around now.(D-spec)
Update 2
My issue with the brakes was never addressed quite satisfactory. There always was a tendency for the front to lock up and confuse the ABS, resulting in scary braking.
Especially at an intersection with red light camera. There they turned the yellow light duration to someting like 0.5 seconds and you have to make a quick decision to stop as soon as yellow shows up...

So, I decided to buy rear brake pads from Subaru, to test the info that I got repeatedly from the Brembo distributor, that these were engineered for the OEM rear brakes.

The first thing I noticed is that the OEM brake pads were wider by 1/8" on the contact patch.
Long story short, now I'm in better shape.

Update 3
Noticing that my Brembo provided DS1000 Ferodos are really thin now and seeing how firction coefficient-sensitive this setup is, I am trying to find out what has the same coefficient with those.
I have gotten an answer from Ferodo.
They were nice enough to clarify that the product is actually HP1000 and that it is a compound they use with Brembo for brake pads and the equivalent material in the racing range is DS2500.
The FM1000 is used for HP (high performance) applications by Brembo.

So I ended up getting the StopTech Street Performance brake pads for the front and rear of the car.

I also replaced the rear trailing arm front and rear bushings. The front with Sti pillow ball and the rear with Sti Group N.

I drove couple days with the Stoptech pads in the front and the Subaru genuine pads in the rear.

The Brembo OEM brake pads that come with the Brembo GT have a very high grip when cold even and continue with a very high initial grip, when they warm up.

There was no way for the OEM Subaru pads to keep up with that.
With the Stoptech in the front, the OEM rear pads had a chance to bite a bit and it took quite a bit of bedding at moderate speed, for the rears to start to be felt.

Once I replaced the rears too, I went for another set of bedding.
The one thing I'm still trying to figure out is that, after 2 sets of 10 slow-downs, the rear calipers got really hot, while the front ones, you could put your finger on the caliper and keep it there, the caliper was cool.

Maybe bedding pads on the Brembo GT takes something more severe than 10 slowdowns from 60 to 10 MPH.

I guess what they forget to advise you of, with this particular BBK kit is that it is ballanced, if you run the same brake pads front AND in your OEM rear calipers. DS2500 for the really small 2002 rear brakes are around $140. Probably worth it, at the track.
The Stoptech SP are a much better deal.

Getting the bushings done helps to even it out. I did have the Sti front control arms in the front, which were brand new and added rigidity to the front brakes.

Brembo GT Information Source, Part 7: Influence of BB kits over ABS, misc info

I wanted to link here a Stoptech article about the influence of BBK on ABS.

Also, I had some incidents with front ABS kicking in early/too strong (it seemed). I still didn't bleed the rears yet. Also, there's something about reverse bleeding the front Brembos.

Some more info: The 328mm kit, as well as the 332 does not need the rear Brembo upgrade, for sure.
I'm talking about the 1A1.6010A and 1H1.7001A
Basically, although the front rotors are larger in diameter than the Sti Brembo front rotors, the pistons are such that the rear upgrade is not needed.
The Brembo gold caliper kit with one piece rotor, 326mm still needs the rear upgrade.
The rear brembo upgrade is quite similar with Sti rear brembos, with drum matching the rear WRX shoes and drilled rotor. It shows in the literature as being 1-2 lb lighter than the regular Sti rear rotor.

I know that the Sti rear brake upgrade for WRX is done these days with the 170mm drum rotor but this rotor is much heavier than the Sti rotor, so I don't think that the 170mm extra thick shoes is a bad option.

I still have what I perceive as a brake torque imballance, tried bleeding the rears, as well as checking tire pressure (OEM now), next, I will try setting the Tokico D-specs to allow more loading of the front brakes, for more braking tire grip and later ABS actuation.

I got info that under normal/spirited driving conditions the Brembo friction rings may last 40K miles, with Ferodo pads.

I think now that my ABS braking problem from medium speed may be a form of the ABS on road imperfections problem.
It feels different than before (before meaning back in the days before the Subaru ABS campaign, in '06)

Brembo GT Information Source, Part 6: Brief review

My brief review of these:

-The OEM Ferodo pads are very very dusty
-They seem to begin working immediately, when I drive out of the carwash, the OEM needed 2 applications, with wet rotors.
- They make an oddball clunking/clamping noise when you reverse while parking (on the BMW forums someone compared it with kicking a full washing machine)
-The "added lightness" was imediately noticeable to me in acceleration. If you were to replace heavy Brembo OEM rotors, it should be even more noticeable
- I did not notice a severe front bias even with emergency brake testing with these. In dry weather, the ABS worked fine and my car has the ABS recall, the functionallity of the recall is preserved, I don't have that momentary loss of brakes, not even with these. I did not get the ABS to kick in in the rear anymore, but I haven't bled the rears in a while.

Brembo GT Information Source, Part 5: Spares

There is information available for the Brembo ring replacement procedure, Race Technologies has that.

One of these guys has posted on many forums. In one of the postings on a BMW forum, he noted that the installation hardware is designed to outlast the friction rings, but should be replaced at the time the rings are replaced.

The hardware comes with treadlocking compound already applied on its bolts and can be in the $100/wheel range, for just the fastening hardware, so you can replace the rings.

There are two cheaper sources for ring replacement.

One is Racing Brake, which provides a 330x28mm ring

This "may work" for 328x28mm applications, according to the site. It comes with its own hardware.
Important to know is that if you have the "old style" Brembo hat, you will need to have a lip machined inside the Brembo hat, to make these fit.

Another is Stoptech. they provide a 328x28mm replacement

My understanding is that the "new style" stoptech ring does not need the Brembo hat machining. This comes with its own hardware kit.

It is important to understand that the 3 options have 3 different installation methods. If you get the method wrong, you could be in danger of loosing your brakes.

Here is a site that has several of the installation instructions

In the past there have been problems with a hybrid rotor at the track. This has been debated a lot in BMW forums.

Here is a link to an older thread that discusses this.

My understanding is that the kit shown there has been changed and now requires no machining.

Here is some info about brake pad replacements:

Brembo GT Information Source, Part 4: What to look for, when purchasing used

What to look for, when buying these used:

-Be aware that even the most expensive Brembo calipers have an oddly low quality powder coating prep job.
What I mean is that the piston boots are "painted in" (powdercoated), just like the window moldings would be in a cheap car paint job.

I thought this surely means the calipers are refinished, then watched these videos on youtube.. Look around the outer rim of the boots, you can just peek inside the calipers.

-Many kits come on the market used with crossdrilled friction rings. When new, these holes have visible chamfer on them. When the chamfer is gone, the ring is most likely at minimum thickness.

-The brake pads for this kit are quite thick when new, 15mm. So they may seem to have a lot left, when you see them used, but may have only a quarter or less life left. OEM-Brembo pads are expensive, but there are other options available.

-If you have to replace the rings, with Brembo replacements and Brembo fastening hardware, you're spending in the $750-850 range....

Brembo GT Information Source, Part 3: Finishing Installation

So I needed to be sure which way the bracket goes in, in case the treaded holes are tapered, so I don't damage them.
Turns out that as shown in the photos is the only way it will go in correctly.

Once I figured this out, I was able to torque the bolts and the brackets held fine.

I've read in a thread about D2 brakes (different brakes, similar mounting system), that an Australian had problems with the 2 hub bolts loosening at the track and what worked for him was a small amount of treadlocker blue.
Subaru does not mention any treadlocker for these 2 bolts, but maybe there is more vibration with these and they are treading into aluminum, so I used it.
Any liquid can act as a lubricant, modifying the tightening torque perceived by the torque wrench. I decided to ignore this and was fine.

Then I had to install the calipers, the caliper bolts and tighten them. These bolts are shown in the above instructions to be tightened to 80 ft lbs.
The problem is that in the instructions a different style bracket is shown, one that has studs. You're fastening steel to steel at 80 ftlb in their diagram.

I decided to apply 80 ftlb, it was fine. No treadlocker here. I was hoping to get a bit better support with this issue. I got an installation drawing but no torque confirmation.

One thing to note is that the rotor hat thickenss is smaller with the Brembos. This effectively changes the wheel offset.

Brembo GT Information Source, Part 2: Installation


The old calipers are mounted with the "bracket" outboard (bolt heads behind hub)

The Brembo bracket has to be mounted inboard, (bolt heads in front)

I've located a copy of the installation instructions here:

Now with this, the Brembo bracket will be the nut, it's aluminum and the factory torque for fastening the caliper to the upright needs to still apply.
Once I've confirmed this, I knew I have to use 59 ft lb, into an aluminum aloy piece.
The bracket is a bit weird. As you tread into it, it acts like threads may be tapered, the deeper you go, the more it locks the bolt. This is my observation, I was not able to confirm it.
I was however able to confirm the part number, which is printed nicely on it. It is the right one for my car. So whatever features they built, they meant them for my WRX.

The next thing is that the bracket is not symmetric.

You can see in the above picture that one side sticks out at the mounting points. This is how it needs to be installed.

The instructions have you remove the dust shield unless there is a 3mm rotor-shield clearance all around. In preparation to this, I've read the Subaru factory repair manual, that shows the shield not coming off unless the hub is pressed out of the upright, like for bearing replacement.

So I prepared to cut the shield out.

I found that my early '02 had a different shield, much smalled and it did not go full circle around the hub, it was half-moon style. I could have removed them, but with couple hammer blows, I've obtained the 3mm clearance and decided to keep them in place.

Brembo GT Information Source, Part 1: Intro

Brembo GT information source

I've bought a set of Brembo GT brakes for my WRX and have spent some time acquiring information.
I decided to share what I found, to make life easier for those that buy these in the future.

My set is for the front only, with 328mm, 2-piece rotors and 4-piston calipers.
The calipers are radial mount with a bracket that is bolted to the upright, behind the hub.

The calipers are the Brembo A family. These can be used for smaller size rotors, upto 328mm. Below 328 the next size down are 1-piece rotors.

In the Tire Rack product page, these are shown as front-only system, designed to work ballanced with the OEM rear brakes. I thought I have seen a foot note in one of the many Brembo online catalogs I looked at recently that disagreed.

The 328mm fit no problem under my 18" Rota Formula.

The 2-piece rotors in the Brembo GT line-up are floating rotors. Yes, rotors can be of a floating type as well. Not all 2-piece are floating.

This means that the friction ring is attached to the hat with hardware that leaves some room for both axial and radial relative motion.

Some of the following information is first hand, from my installation, some is from Race Technologies, who are Brembo's US representative and some is from internet forums, especially BMW forums.
I'll note the last source, as it's not "confirmed".

Among advantages:
more even wear, lack of distortion of hat under severe heat/expansion, weight reduction,
reduction/elimination of knock-back (this from BMW forums).

A fact:
-The 328mm kit is lighter than the smallest WRX OEM 2002 front brakes.
The rotating mass reduction is over 2 lb/wheel. The caliper is noticeably lighter too.

Monday, August 13, 2012

EJ207 ID info

[B]How to ID your EJ207[/B]
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.

[B]What if the sticker is missing, or you suspect it's faked ?[/B]
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.

Here are some photos of these.

[B]Typical tune up and replacement parts[/B]
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.
[B]Spark plugs[/B]
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.
[B]Head Gaskets[/B]
The V7 gets 11044AA482/483, the same as an '02 USDM WRX EJ205.
The V8-9 gets 110AA651, not the same with any USDM gasket.
[B]Timing belt[/B]
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.
[B]Water pump[/B]
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.
[B]Accessory belts[/B]
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
[B]Coil Packs[/B]
V7 get the USDM WRX 2.0 coil packs for '02, the rest get the '05 WRX ones.

[B]Twinscroll wastegate actuator[/B]
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
[B]Final notes[/B]
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.
[COLOR="DarkGreen"]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.[/COLOR]
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

EJ207 Engine Swap Info

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 will not talk to any unit, other than 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 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..

-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.

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 crank and cam sensors, 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.

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.

General 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.
I think I saw a ROM for a South African market version.
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.
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 99 with semi-closed deck and coil pack over manifold.
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 have separated this engine from the other S engines, because I have read from some sources that it came with a special exhaust manifold, equal length. 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 equal length headers and the settings differ 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.

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 below has no marks.

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.

 This image has been resized. Click this bar to view the full image. The original image is sized 1234x896 and is 811KB.

 This image has been resized. Click this bar to view the full image. The original image is sized 1345x911 and is 792KB.

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 an updated block, and crankshaft and heads. 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, with 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, but the TGV partition wall inside the TGV body is not. 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.
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.
There is 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. Some people on the forum (including me) feel that with this location the readings are accurate enough, down to the limit of this unit. It is still not a wideband, you won't have readings in the 11 range and below.

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.


Welcome to SubMachina, a place where you can find info and read stories about cars.

I will share here among other things, info that I have put together about my Subaru WRX, powered by a JDM EJ207 STI engine.