So you've bought youself a JDM twin turbo eh? [Archive]

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Reuben

04-10-2019, 08:24 AM

I'm seeing a lot of TT's starting to pop up stateside now, I've helped out a couple of the boys out in the pacific northwest with theirs, but there's more and more entering the states now that they've hit that sweet 25. SO. This thread is for those that just got their own TT, and now have the joy of working on them... There's going to be tips and tricks, pitfalls, and work arounds. Don't worry, there's only a small bit of devil magic in these engine bays, otherwise they are pretty straight forward!!! I will be updating this thread as it progresses, and adding Q+A's into this first post.

Working on Subarus Sequential Twin Turbo.

Pictured, an 1996-1998 BG5B GTB
https://sl-i.net/FORUM/images/imported/2019/04/neY3VSh-1.jpg

Working on a twin turbo is very similar to signle turbo, only a bit more shit. As far as removing turbo's, playing with exhausts, this should all be like USDM stuff... But when it comes to vac lines, it's easy to get yourself in trouble.

Tip Number ONE: DO NOT PULL THE VAC LINES OFF THE BLACK BOX. On top of the black box is a 10mm bolt, securing down a fork shaped clamp. The fork shaped clamp is holding in up to 4 vacuum plugs, that have up to 4 vac lines on each plug. These plugs are numbered, and keyed, so it is impossible to fuck it up. The intercooler has it's own plug, the secondary turbo has it's own plug.... knowing this one fact will help you not fucking up your vac system!!!
The black box (of Death)(Aka BBoD), is the muscle of the twin turbo operation. Inside the black box is multiple solenoids, as wll as your map sensor. Like sinlge turbo, you have a pressure select solenoid inline before the map sensor, and you have a boost control solenoid. Important to note is the boost solenoid inside the black box is not actually controlling boost, it's actually the secondary turbo exhaust valve. The cars boost control solenoid lives in the left (passenger side) fender. Also in here are solenoids to control your secondary boost bypass valve, your intercooler secondary butterfly valve, and some other random shit. You won't ever need to know this stuff cause it's just not part of any maintenance or repair you'll ever do. I work with these cars on a semi profesional basis, and I never have had to go into the guts of a BBoD, any boost issues are normally outside of this box, usually because muppets have fucked with something in the engine bay and broken it.

https://sl-i.net/FORUM/images/imported/2019/04/vFOCETA-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/SN3fuY8-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/TdpuI0W-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/dreWMWr-1.jpg

Here's a video on how to remove and re-fit the intercooler properly!!! This is the easiest way, trust me, I've only done it 100 times.
https://www.youtube.com/watch?v=ywQvkwPLieo

Another issue you will likely face, is a TT that isn't performing right. Sometimes if they perform so poorly, they can throw the dreaded code 66! Never fear, code 66 is widely missunderstood. In all my dealings with it, it's never been major, it's always been some vac line someone has changed, or that has snapped. Though I have read of people who have needed to clean out their BBoD to sort it. Put simply, code 66 is the ECU figuring out that yo car aint boosting proper! that's it. Unlike the other 60 codes, it's not linked to a specific solenoid or sensor. It usually comes on when you've got the engine loaded, that is, say, going up a hill, but the primary isn't coming on boost. The last 66 I solved a few months ago was a customer who had just bought a GT VDC, but it looked as though the engine had been replaced with a non VDC engine, and the mechanics who had put it in had done the vac lines up following a non VDC vac diagram. I corrected the vac lines, and presto, primary started to boost proper and code 66 went away. I've also seen 66 in cars where people had replaced their vac lines with silicone. Don't be that guy, you're just opening yourself up a world of hurt. Code 66 can also come on when your primary turbo dies. And yes, primary turbo's dying is a way of life for twin turbo's. I wouldn't say it's as prevelant as EJ25's blowing headgaskets by a long way (nothing is), but it is common still. You can still buy primary turbo's new though! (Update: From where I don't know, the guys in NZ who were importing them have stopped) So if you get code 66, check ALL of your engine bay vac lines against the CORRECT vac diagram. Keep reading to see how to identify what vac system you have.

ECU Error codes are listed at the end of the thread, including the 60 series of TT codes.

Now to the engine bay... Now this is where I tell you there's actually 4 different types of black box, and associated vac line setup. You have BG5A, BG5B/C, BH5A/B/C and BH5D, And for bonus points, BH5A/B/C WITH VDC (twin vac line BOV's anyone?). Online you will find BG5A, BH5A/B/C and BH5D info, but curiously you wont find BG5B/C. I plan to change this is the near future as I am sick of not having diagrams of the vac system for BG GTB's. - EDIT, done, created a B/C rev BG vac line layout, posted below! You're welcome!
Some of the big differences are for example, BG5A has a wastegate on the secondary turbo, but B/C does not. BH is different again, and Rev-D's simplified things a bit. BH's are much more confusing than BG's, lots of tee pieces around the BOV/primary side for some reason...

https://sl-i.net/FORUM/images/imported/2019/04/50036468907_5b010e39be_ogif-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/50036468872_a2a122e5c6_ogif-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/50036211956_6bfe6352eb_ogif-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/50035664443_bddfb335a3_ogif-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/50998501889_543a1229dd_b-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/51083517967_a8e2cacd36_b-1.jpg

https://sl-i.net/FORUM/images/imported/2019/04/51014265470_2fa81cd042_o-1.jpg

Engine/Model Identification:

Engine identification... What twin turbo have I, and why does this vac line pic I found on the googles not resemble my engine bay in any way... So a big part of knowing twin turbo, is knowing what type you are dealing with. As mentioned above there's 4 (5) types of vac line arrangement, but it goes much deeper than that. Spanning the 10 year life of TT was multiple engine generations. We started with hydraulic lifter engines like USDM 96 outbacks, and ended int he bug eye generation with phase-III top feed injector goodness. Here's the break down

2nd Gen legacy, Pre facelift 1993-1996
Chassis: BD5A, BG5A.
Engine generation: Phase-I
Engines: EJ20H
Power: 250ps/246hp/183kw
Valvetrain: Direct HLA
Compression EJ20H - 8.5:1
Quick id: Rocker covers have lines embossed, 6-bolt.
USDM part commonality: EJ25D '96
JDM single turbo part commonality: Ver. 1/2

Interesting notes: All pre facelifts have the same engine, auto or manual. All engines are hydraulic lifter (Direct HLA, with lifter in bucket, rather than rocker like in the first gens), these engines are common with your first year EJ25D, found in the 96 outback, that odd one that has lines on the rocker cover... Why did the US only get that engine for one year? well that just happened to be the last year of production for hydraulic DOHC engines, this generation engine had been in production from 92 till 96 in japan.

2nd Gen Legacy, Facelift. 1996-1998
Chassis: BD5B, BD5C, BG5B, BG5C
Engine generation: MASTER-4 (Phase-I)
Engines: EJ20H, EJ20R B-Rev, EJ20R C-rev
Power: EJ20H 260ps/256hp/191kw
Power: EJ20R 280ps/276ph/206kw
Valvetrain: Solid lifter, shim over bucket
Compression: EJ20H - 9:1
Compression: EJ20R B-Rev - 8:1
Compression: EJ20R C-Rev - 8.5:1
Quick id: Smooth rocker cover, 6-bolt. EJ20H grey injectors, EJ20R yellow injectors.
USDM Part commonality: EJ25D '97+
JDM single turbo part commonality: Ver. 3/4

Interesting notes: Facelift introduced the GTB. The GTB is not a "spec.B", it's a GTB (spec.B started with 4th gens). There was a divergence in the engine types from this point on, and we get 190kw engines, and 206kw engines.
EJ20H: This is the 190kw engine. This is a different engine to the pre facelift. this engine has solid lifters with shim over bucket, these engines are like the late 25D's, and EJ20K's (V3/V4 STi motor) etc. EJ20H's of all forms come with grey top injectors.
EJ20R: Physically looks identical to the smooth cover 20H, same rocker covers etc. Camshafts are different, compression ratio is different, turbo's are different, air flow meter and injectors are different. Power is a glorious 206kw. These engines are the twin turbo version of the EJ20K. The only difference from the 20K is there's an extra hole bored in the left head for the primary turbo, shim over bucket, unlike the 20K which is shim under bucket, and cast pistons, unlike 20K's forged pistons. Piston crown is the same design, camshafts are the same, head castings are the same. Interestingly with the EJ20R, the B-rev was 8:1 like the 20K, C-rev was 8.5:1... EJ20R's have yellow injectors and orange air flow meter like the 20K.
EJ20R's are found only on MANUAL GTB's (and RSB). Auto GTB's got the 20H. GT's got the 20H.

WARNING!!! Mechanics who don't know this shit, and who don't give a f*ck, have been working on these cars for 25 years by the time you get your mits on them, there is no gurantee that just cause you got a manual GTB, that you have an EJ20R in your car! I have seen hydraulic engines in GTB's, I have seen grey top smooth 20H's in GTB's. Mechanics here when they get a GTB with a blown engine usually have no idea that the EJ20R is any different to an H, and will slap whatever twin turbo they get their hands on in the hole. So yeah. enjoy. and also, sorry.

3rd Gen legacy, Pre facelift. 1998-2000
Chassis BE5A, BE5B, BH5A, BH5B
Engine generation: Phase-II
Engines: EJ206 A/B-rev, EJ206 A/B Rev with VDC, EJ208 A/B-rev
Power: EJ206 260ps/256hp/191kw
Power: EJ208 280ps/276ph/206kw
Valvetrain: Solid lifter, shim over bucket.
Compression: EJ206 - 9:1
Compression: EJ208 - 8.5:1
Quick id: Smooth rocker cover, 8-bolt. Intake manifold has flat runners on passenger side (where the coil pack would sit on an WRX of the same year)
USDM Part commonality: None
JDM single turbo part commonality: Ver. 5/6

Interesting notes: Engine design starts to converge again. Still EJ206 in GT's and Auto GTB's, EJ208's in manual GTB/RSK's. Now all motors have same air flow meters, and yellow injectors (larger body than the older injectors, these are the same fitment as EJ25D red top injecotrs funny enough). Much like the smooth cover EJ20H vs R, there's no way to tell these engines apart visually, and it's especially hard since they both have yellow injectors (at least 20H/R had grey/yellow). There's nothing much to say about these engines. They are Phase-II DOHC, you didn't get this type of motor in the states, since they killed the 25D and went to EJ251's, blegh. They are more similar to the Phase-III motors you're used to seeing in the bug eys, same manifold bolt pattern, fat cam seals and all that jaz. In japan this is when the EJ204 and EJ254 DOHC AVCS Non turbo's were introduced, so they have common parts with AVCS engines such as cam seals and rocker covers etc. They are a little odd, cause they are like an AVCS head, but have no AVCS.
The VDC (Vehicle Dynamics Control) equipped cars have a different vac layout, as there's an extra solenoid to control the BOV, and the BOV has two ports. VDC could solenoid open up the BOV to kill your power as a form of traction control. These cars are hilariously bad when fitted whith shitty chinese tyres, as they will wheel spin in first, VDC will traction control you and kill the power, then the auto gets confused by what's going on and shifts and bogs you down. Yaaaaaaay. Do not buy VDC cars when they become available stateside, they are shit to drive, and shit to work on. If you end up with one, buy good quality tyres, only buy them in sets of 4. Do not modify your engine in any way shape or form, the ECU will have a FIT if you touch anything in the engine bay, they are really really tricky to work with, in essence, VDC cars are unmodifyable.

3rd Gen Legacy, Pre facelit 2000-2001
Chassis BE5C, BH5C
Engine generation: Phase-II
Engines: EJ206 C-rev, EJ206 C Rev with VDC, EJ208 C-rev
Power: EJ206 260ps/256hp/191kw
Power: EJ208 280ps/276ph/206kw
Valvetrain: Solid lifter, shim over bucket.
Compression: EJ206 - 9:1
Compression: EJ208 - 9:1
Quick id: Smooth rocker cover, 8-bolt. Intake manifold has high rise runners both sides
USDM Part commonality: None
JDM single turbo part commonality: Ver. 5/6

Interesting notes: Kind of an oddball car these. They are mostly the same as the other pre-facelift, still have yellow injectors, still phase-II, make same power etc. The intake manifold design changed, no longer did they have the flat half, both side runners go high. EJ208 got a compression ratio bump to 9:1, now the same as EJ206.

3rd Gen Legacy, Facelit 2001-2003
Chassis BE5D, BH5D
Engine Generation: Phase-III
Engines: EJ206 D-rev, EJ206 D-Rev with VDC, EJ208 D-rev
Power: EJ206 260ps/256hp/191kw
Power: EJ208 280ps/276ph/206kw
Valvetrain: Solid lifter, shim over bucket.
Compression: EJ206 - 9:1
Compression: EJ208 - 9:1
Quick id: Top feed pink injectors
USDM Part commonality: GDAA, "Bug-eye"
JDM single turbo part commonality: Ver. 7

Interesting notes: Phase-III is here, enter the modern age! These engines are common with bug eyes in almost every way, except AVCS. Manifolds though are very similar design to the C-rev, only now they have pink top feed injectors like JDM EJ207 bug eys. These engines have all the short block goodness of the bug eyes too, gone is the big end bearing unreliability of the old phase-I and phase-II engines. (And don't laugh, you guys think big ends in USDM turbo subies are unreliable... they are not, they have got NOTHING on the unreliability of the EJ20R and EJ208, NOTHING I SAY). These cars are somewhat sought after here, as the twin turbo system in them is PHENOMINAL compared to the older ones, they actually do what you think they should. They are pleasing to drive, and reliable. Subaru essentially after 8 years perfected twin turbo... Only to drop it 2 years later with the introduction of twin scroll turbo's on the 4th gen.

Conclusion on engine differences. As you can see it can be very hard to identify the difference between them. EJ206's and EJ208's of the same year appear identical on the outside. So yeah, good luck. Your only hope is to pray that the engine in your car is original, and that you can rely on the vin plate.

Parts
Part info coming later.

Technical Docs
Here's a link to my google drive that has pinouts for all the JDM models I can find, and wiring diagrams for all the models I can find. Of not is the absence of BG wiring diagrams. Never found one, not in 15 years. The Impreza V3/4 wiring diagram is 90% applicable, with the USDM outback wiring diagram filling in another 5% missing stuff. But no joy on the TT specific wiring.

Pinouts are in their own folder. Wiring diagrams are in the chassis specific folders with the rest of the FSM's

https://drive.google.com/drive/folders/0BxbF2GA67ZUNUWYwb19uS1FlOVE?resourcekey=0-hhnwqwRX0MW0axi61_xFbQ&usp=sharing

But Reuben, how does TT actually work?
Like... How does it actually chooch? Why does it have a dead spot at 4000rpm?
https://sl-i.net/FORUM/showthread.php?6661-Twin-Turbo-Myths

CEL Error codes:
To pull codes, it's the same process as SSMI (OBD-I) cars like the Legacy SS, SVX etc in the US. This is the guide I've always used: https://legacycentral.org/library/literature/codes.htm

Remove the kick panel under the steering column. To the left of the steering column will be a bundle of wires with a bunch of disconnected connectors. Among them will be a pair of T-shaped (normally 2-pin) connectors, populated with only 1 pin in each side, and a pair of black spade terminal stile single pin connectors. Sometimes these are taped up to the bundle with blue electrical tape.

The green connectors are the Dealer Check Connectors, and the black ones are the Read Connectors. With the ignition off, connect the read connectors together, turn the ignition on (don't start the car), and read the blinking CEL. The CEL will present a 2-digit code, the first digit is represented with long flashes, the second digit with short flashes. So if you get Long-Long-Long-Short-Short, that's 3-2, or code 32. then there will be a longer pause, and the next code will display. Once all codes are displayed an ever longer pause will occur, then it will repeat the codes.

The codes are displayed in order of most recent codes first, oldest last. So once you have gathered all your codes, turn the ignition off and on again, and just check which code is the first one, this will be the most recent CEL.

To use the D-check mode, start with both connectors disconnected, start the engine, allow it to warm up, then turn it off. Next, connect the test mode connectors (green T-shape). Turn ignition to ON position without turning on engine. At this point if the check engine light does not come on, it is faulty and must be fixed before continuing. Depress accelerator pedal to floor, return to half throttle and hold for two seconds, then release. Start the engine. Now the light can blink in two different ways. If a problem is already detected, it will blink according to the chart below. Your next step will be to drive the car with the test mode connectors connected. You must drive over 7 mph for at least one minute, and shift up to 4th gear if you have a manual tranny. Now, either you will discover your trouble codes, or you will have none.

Driving in D-check mode makes the ECU do a more thorough audit of the sensors, and operation, and will more readily pull up codes that might not otherwise pop up.

Lastly, to erase trouble codes from the computer (without resorting to the infamous battery disconnect dance), repeat the above D-check procedure exactly, but connect both the green and black connectors at the appropriate time.

(Yes these work on JDM BH/BE models)

11 - Crank Angle Sensor
12 - Starter Switch
13 - Cam Angle Sensor
14 - Injector 1
15 - Injector 2
16 - Injector 3
17 - Injector 4
21 - Water Temp Sensor
22 - Knock Sensor
23 - Air Flow Sensor / MAF Sensor
24 - IACV / Idle Control Valve
31 - Throttle Position Sensor
32 - o2 Sensor (Pre cat)
33 - Vehicle Speed Sensor (In instrument cluster for BG/BD)
35 - Evap Purge Solenoid
41 - A/F Learning Control
42 - Idle Switch
44 - Boost Control Solenoid / Wastegate Duty Solenoid
45 - Manifold Absolute Pressure Sensor / MAP Sensor
45 - Pressure Select Solenoid (The wee solenoid between the manifold and MAP sensor)
49 - Improper MAF detected
51 - Neutral Switch (MT)
51 - Inhibitor Switch (AT)
52 - Parking Switch
58 - Vacuum leak detected by ECU

TT Specific codes:

61 - Air Suction Control Solenoid Valve (BBoD Solenoid - Controls vacuum to the vacuum cannister?)
62 - Exhaust Valve Control Solenoid - Negative side (BBoD Solenoid)
63 - Supercharging Relief Valve Control Solenoid Valve (Primary) (Main boost solenoid in passenger side fender)
64 - Supercharging Relief Valve Control Solenoid Valve (Secondary) (BBoD Solenoid - A-rev BG only, NOT the main duty solenoid in the BBoD)
65 - Differential Pressure Sensor (On firewall)
66 - Twin Turbocharger System(H)
66 - Twin Turbocharger System(S)
66 - Twin Turbocharger System(T)
66 - Two Stage Twin Turbocharger System
67 - Exhaust Valve Control Solenoid - Positive side (BBoD Solenoid)
68 - Exhaust Valve Duty Solenoid - (BBoD Solenoid - Main duty solenoid in BBoD)

Uh-oh, I got code 66…
Code 66 is used by the ECU if it detects the car is running like shit. It's not related to a specific solenoid, rather the overall health of your vacuum layout, or the turbo system in general. It can crop up when the vac lines are put back together wrong, like what happens where someone fucks around and uses the wrong diagram, or if a hose has snapped/fallen off somewhere for example. It also happens if you have a turbo not boosting enough, or sometimes boosting too much. Essentiall it's a catch all for when the expected boost curves are not being reached, which could essentially be anything.

When code 66 comes on, there is a hard cut associated with it, it's normally pretty violent. To get home, turn the car off, and back on again, and just drive gently.

To rectify a code 66:
Check for intake pipe leaks, common leak spots are where the PCV plumbs in (under the throttle body, the pipe cracks) and the soft rubber seals onto the front of the turbos.
Check for boost leaks where the intercooler hoses clamp to the turbo's, it's very common for these to get folded over and leak when the intercooler has come off and gone back on again.
Listen out for the primary turbo screetching or excess oil smoke coming out the exhaust, in case the primary turbo is blown.
Change your spark plugs, while in there, check to see if one of the coil plugs has come loose, running on 3 cyls can sometimes trigger 66.
Check or try a new MAF sensor, if it's far enough out of calibration, the resulting reduction in performance is enough to trigger 66 sometimes, even if not pulling codes for MAF.
Do you have a small pod filter? Bin it, go back to stock, or get a proper high flow filter, the casiest case of 66 i have heard of was a pod that was too small, and choking the car as secondary tried to come online
Lastly, if none of that helps, verify your vacuum layout matches the layouts published above.

MODIFICATIONS

LINE 10 MOD

Line 10 mod bad, no do.
Also it can only be done to BH's, but it thrashes the primary, I've replaced a few primary's for customers now, who had the line 10 mod, normally about a $1200 job if yah unlucky and are paying full retail ($400 in time, $600 for the turbo at wrecker prices in NZ). I've also seen people try do it to BG's, but you can't... so naturally that goes about as well as you'd expect... So yeah, fucking forget the line 10 mod.

Onto more positive things.

FITTING A NON WASTEGATE SECONDARY TO A-REV BG/BD's

Sometimes you own a BG5A/BD5A, and ya turbo's fuck out, or they just aren't boosty enough for yah... So you go chuck on the big boys off a BH D-rev... WELL, if you look at the above diagrams real close you'll note the BG A-rev's have quite a different vac system... there's a heck of a lot more vac lines... and yup, that's a wastegate on the secondary turbo in ya A-rev... Well WTF are you gonna do about the vac lines for that!? Simple, turns out only two lines need to be delt with.

Line 16 is the duty solenoid positive pressure reference (Only has positive pressure once secondary is online, and the intercooler valve is open).
Line 8 is the duty solenoid to wastegate line.

Remove line 8, it's useless now.
Block line 16 at the junction tube thing above the secondary pre-spool releif valve, and remove the line to the BBoD if you want. Or if you wanna get real fancy, replace this junction pipe with one from a facelift or BH, it will only have one vac port, not two!
Well done, you now have a Secondary-sans-gate running in yah A-rev.

If you do not do this, every time you hit secondary, the ECU will be opening up the solenoid, and suddenly you have a pretty modest vacuum leak. With 16 blocked, no more leak, and the solenoid will just chooch away on it's own affecting nobody.

So this is a work in progress, that took me 2 hours to write, I now have to proof read it, flesh it out, format it, take photo's and find photo's online. Please ask questions, I want to add as much info in here as possible for you poor cunts. Welcome to the world of twin trubo f*ckers, enjoy your stay!!!

Change Log:
25/09/2021:
Added another link to the Google docs tech documents, I was getting notifications that Te link was out of date? Try both.
30/03/2021:
Added BBoD Diagrams
04/09/2020:
Added modifications section
23/06/2020:
Updated all vac layout images, now they are common with each other.
Added Rev-D vac layout image
Added link to my video showing the correct pocedure for removing and fitting the intercooler
Added CEL codes, including 60 series codes for TT.
The NZ suppler of new primary turbo's (I think they had VF 13's and 26's) has stopped importing them. They no longer list them on their website - It was turbochargersNZ
Added link to my google drive with the pinouts and manuals I have.
14/05/2024:
Updated the CEL section. Added how to retrieve codes, improved the description of code 66, and added items to check over if you get code 66.
07/07/2025:
Fixed referring to 4th gen spec.B's, as B-Specs. B-Specs were a JDM BG Pre-facelift trim option of the GT, where-as spec.B's are the replacement of the GTB from 4th gen on.

Red85Celica

04-13-2019, 01:08 PM

I'm so glad you're around and willing to help me with my shitty A-rev I need to become the master twin turbo guy in the US.

Reuben

04-14-2019, 02:20 AM

I'm always happy to help! Never be afraid to ask questions. And I'm continually updating this post, there should be some pics now! I just gotta get my hands on an A-rev to take pics of (not hard here, fucking everywhere), and a BH with and without VDC. Flatmate has a rev-D also, so am sorted for rev-d pics.

Perron

04-29-2020, 10:22 AM

Well first off, I myself have a BH.
2001, BH5D has an EJ206 2.0L twinscroll..

My legacy seems to have some issues, I have a two engine codes P0340 (Camshaft position sensor "A" Circuit bank 1 or single sensor) And P0171 (System to lean Bank 1).
Your thread made me think perhaps I am having a vacuum issue. I've noticed, cold starts if I don't let it run for a minute before putting it in drive, it literally 'putts' around like a go kart and the gas pedal does little to nothing... I've also noticed going up hills it barely makes it sometimes. I've replaced the spark plugs. both codes were present before and after spark plugs were replaced.
I've been told to replace the Lambda / O2 sensor, but I unplugged it as a test and it didn't do anything except add an engine light to my cluster.

Also, if you're still in need of some photos of a BH I may be able to help you with that!

Reuben

04-29-2020, 06:42 PM

Reuben

06-23-2020, 03:44 AM

Updated 23/06/2020

Change Log:
Updated all vac layout images, now they are common with each other.
Added Rev-D vac layout image
Added link to my video showing the correct pocedure for removing and fitting the intercooler
Added CEL codes, including 60 series codes for TT.
The NZ suppler of new primary turbo's (I think they had VF 13's and 26's) has stopped importing them. They no longer list them on their website - It was turbochargersNZ

mike-tracy

06-23-2020, 04:59 PM

Now that ej20h based Legacys are legal in the states, I anticipate seeing more questions about these going forwards.

Thanks for the Update Reuben.

Reuben

09-03-2020, 05:06 PM

Exciting news! Got some hardcore JDM only wiring diagrams coming for BG, such as the climate control computer wiring! Stay tuned.

Perron

09-08-2020, 08:33 PM

Take your alternator belt off and go for a test drive.

Edit: Explanation; the alternators in the 3rd gen's have a common fault, where the reg/rectifier goes bad, they send out electro magnetic interference which get's puicked up as static/noise on the cam and crank angle sensor wiring. The ECU can't interpret it, and so throws codes for cam or crank angle. They can run rough before getting to the point of throwing codes, you don't need the CEL on for this fault to present bad symptoms. It will be a rough idle, or lack of power, much like bad plugs or faulty coils, or a bad MAF. The quick easy way to test if you don't have a $10,000 oscilloscope to see what the cam and crank signals look like, is to whip the A/C belt off and run the car, if it magically runs fine, and the CEL goes away if one was present, presto, time for a new alternator.

Wish I would of remembered I asked that question earlier. I appreciate the reply and wow did it help. I'm currently sitting in my legacy after taking the belt off and it ran great. I was going to take a longer test drive but no power steering is harder to do then I thought! I didn't see any engine light. I will definitely be looking into an alternator.
Also sorry if these replies are off topic of the post!

Edit: Replaced alternator and have no Shaky starts or idling funny at a red light. BUUTTTT I have some other issues I have to workout here now. Again Thanks for the advice Reuben

Reuben

03-30-2021, 06:25 AM

Updated 30/03/21

Added BBoD Diagrams.

Prevo

04-28-2021, 04:31 PM

First off would like to say this is the most information I have came across, so thank you for your time in doing all this.

I recently bought a 2000 BE5 and just getting into the jdm legacy scene. Everything on the car was working great except sometimes when I would be driving, after a 10-15 min drive I would notice a huge drop in my boost (around 5-6 psi) when I would usually get around 12 psi. Before, the the solution that seemed to have worked was that I would turn off my car and then back on again, it temporarily would go back to holding the boost I had initially. But a couple of days ago it fell back to 6 psi, so I thought no biggie ill just do what I have been doing before which was to turn it off wait a bit then turn it back on again. But when i turned it back on again it didnt go back to normal.

could my car have gone into limp mode? I will be getting a obd2 scanner to check for any codes and clearing them to see if that would make a difference.
Not much has been done to the car except the radiator was replaced for a mishimoto one and a boost gauge was added by previous owner. I am pretty much a noob when it comes turbos and boxer engines so any advice or information will be super appreciated.
Thank you.

mike-tracy

08-21-2021, 07:41 PM

Two more years till the 1998 BE's are legal in the states! Is there any standalones that are directly compatible with those?

LosMan603

04-06-2022, 09:45 AM

Hoping this thread is still active, I just purchased a 97 GTB 5 speed! The car is arriving tomorrow with only 53,000 miles and is mostly OEM.

Looking forward to using it as my daily driver, and my kids are excited to see a RHD car :)

Anyways thank you for posting this information, it is a literal gold mine and has already answered sooooo many of my questions and anxieties lol.

Reuben

04-06-2022, 04:53 PM

I still keep this alive and update as I get more info/data!

Congrats on the purchase!

LosMan603

04-06-2022, 10:16 PM

Thanks, I'll celebrate when I get in the driver seat :)

While I count the hours until the 97 arrives, I am already in a bit of a pickle. The car is currently fitted with a HippoSleek grille painted in Alpine White (51E) and I hate it. Actually, I am 90% sure it's Hipposleek but I 100% hate it.

Any idea if a USDM grille could be fitted? Visually the fitment looks really similar in pictures.

Otherwise I may save my pennies for a jdm replacement. Or potential swap with another lucky Legacy owner.

Reuben

04-07-2022, 07:51 AM

Get yo ass onto the 2nd gen legacy enthusiasts fcebook page if it isn't already. I'm sure someone will want to swap for a stock JDM grille. Cause no, you can't ran the US grille, it's too tall. Very poor fit.

LosMan603

04-09-2022, 11:32 PM

You know, now that I can see the BG5 in person, that Hipposleek grille doesn't look too bad :)

One thing I noticed straight away that seemed strange, the BOV has been piped way off the intercooler. Check out this pic... have you seen this type of fitment before?

3775

p.s. here is a pic of the old girl :)

3777

Reuben

04-10-2022, 04:57 AM

No I've never seen that! You could easily improve on that install, that's just lazy.

lord flashheart

04-10-2022, 10:41 AM

No I've never seen that! You could easily improve on that install, that's just lazy.
Imma just keep my hood closed...

LosMan603

04-11-2022, 04:00 PM

No I've never seen that! You could easily improve on that install, that's just lazy.

Haha yeah I was seriously scratching my head when i saw that. Honestly I am not sure I even want an atmospheric bov on the car...

Ideally I would just go back to the stock recirculating valve... having a hard time finding one that isn't on ebay. Any advice on how to source OEM parts or cross ref to usdm stuff that may fit?

I searched a around on this forum but I haven't found anything super helpful yet.

Cheers

PureJDMBG5

06-18-2022, 10:49 PM

Updated 30/03/21

Added BBoD Diagrams.

I’m new on here and to the Suby fam as well. I’ll be getting my act together soon I promise but I’d like to start by thanking you for all the effort you’ve put into the formation you’ve provided. You should have a Patreon account man. Seriously!

Anyway, I was wondering about your single turbo conversion write up. I noticed you didn’t start with revision A. Since that is what I have in my 95 JDM Legacy GT, I’m wondering what would be my best course of action to single turbo this motor? Is it even worth it? Is there a reason you didn’t do a write up for rev A?

My goal for my car is to manual swap and get the engine to be a bit more reliable. The BBOD and all those vacuum line scare me. Luckily my car only has 76,000km’s and is in seriously good shape. I’ve got tons of time to do other things but I thought I’d ask someone who obviously knows a lot more than me. Is it worth it to keep this engine as a base for a more reliable build with a small bump in power? Any and all advice is welcomed and appreciated.

Reuben

06-19-2022, 07:43 AM

It just so happens I updated the single conversion thread tonight, go re-read it my man.

I will ask first, what do you expect to gain from single converting? What are your motivations? If the TT is great fun already, it may not be worth converting. However, you mentioned “slight bump in power”. Thems are dangerous words boy.

If you stay twin turbo. Stay stock. No bumps in power for you. Don’t do it. Basically the TT ECU’s hate changes in performance, and the whole system can collapse if you do anything wrong, like accidentally change a vac line, or use silicone anywhere. But if you single convert, you can mod the hell out of the car and really work that engine into what you want. The block itself is good for another 50hp without any worries. These early 20H’s can put 250hp to the ground in their sleep with an ECU, turbo, and injectors.

Long story short, there is no plug’n’play ECU’s for A-revs. The wiring is closest to BC/BF and GC/GF EJ20G. It is possible to re-pin it to these, or 3-plug of course, but that’s so much work to still be handicapped by stock 90’s ECU’s. The ideal would either re-pin to 4 or 3 plug single ECU pinouts, then get a plug’n’play link or haltech, or just straight up replace the factory plugs with link or haltech plugs and go that way. In other words, the wiring required is that of a stand alone ECU mod, not ya traditional single-conversion swap-a-few-pins-round and ya done. But mechanically wise, it’s all exactly the same.

PureJDMBG5

06-20-2022, 04:56 PM

Cool I'll check out the update as soon as I can and thanks again for staying motivated to provide all this useful info. :headbang:

My goals for the car are a follows:

1) Manual swap with the ECU from a manual JDM GT. I'm pretty sure this is all pretty easy and most shops should be able to do it.

2) Do a single turbo swap so that the engine and maintenance are easier and get a bit more hrsprs. I'm thinking as close to 300 as I can. All info I've seen says the EJ20H rev. A has 247bhp. If it ends up around 260 or 280 I won't be sad. I like to cruise not race around like a maniac.

Can you piggy back (is that the right term of phrase?) another ECU to handle the bump in power from a bigger turbo? I guess the better question is can the place I take the car KNOW how to do it with this engine? Or would a stand alone ECU be a safer easier option? The last thing I want is to take this car to a shop and be yessed to death only to get may baby back and find out they hacked it together.

Seriously the guy who installed my Bilstein Coil Overs and Cusco top hats that cost $3k? It looks like they were installed by a gorilla using a hammer after downing 20 redbulls. They are nicked and dented from the effort of installing them. I'd complain but what would be the use? Just won't ever go there for anything ever again.

My first attempt at uploading a photo. Did it work?
https://photos.google.com/photo/AF1QipMbv-PuMwyo0g8ui_R6lT82_bjyu5eb36rE8l6i

This is where I'm at now with the engine. Again thank you for any and all advice you could offer me. If you were local I'd buy you a beer or two man.

Reuben

06-22-2022, 06:39 AM

No ECU required for manual swap. They’re are the same between auto and manual (basically). You just need to change the state of the AT/MT identifier pin, and that tells whatever ECU that’s in there if it’s an auto or manual.

The autos in the JDM GT’s are VTD transmissions unlike N/A boxes. Kinda sought after for those in the know, but that’s so few willing to do the work on making one run that the market for it is nill :lol:

As for ECU. Buy a link. Dont fuck around. The link eliminates the need for high octane, allows bigger injectors, allows you to tune for your power mods, allows you to throw the MAF in the bin, and simplifies your rewiring for single turbo, and also makes it possible for regular speed shops who already do things like installing ECU’s. Which all makes it easier for you to make more power, safer.

SntSpanish

10-24-2022, 01:29 AM

Picked up a 99 BH5B and its got some issues, when in 2-5 gear at anything over 70% throttle, the car jerks and surges in the secondary turbo rev range. Also throws a CEL. Any help is appreciated

https://youtu.be/yG3L6B5v7jI.
3911
3912

Reuben

10-26-2022, 08:15 PM

I would be checking the vac lines to the turbo, making sure theyre all good. Get a boost gauge on there and see what boost pressure it makes after crossover. if its way down compared to primary, thats where you gotta focus your attention.

Code 66 means “my turbos aren’t boosting properly”, it’s not related to any particular solenoid or sensor, they have unique codes of their own. Basically the ECU is lookibg for a certain boost level relative to engine load (air mass vs throttle position), and if it doesnt reach that boost target, code 66 is thrown and the car violently gets put into limp mode.

So yeah, figure out why its not boosting. Ive seen blown turbos, restrictive cheap pod filters, vacuum lines routed incorrectly, all cause code 66. To be fair the usual culprit is vac lines after an engine swap not being correct.

s0abh4

10-31-2022, 02:35 PM

after finding this post searching everywhere my be5 is alive wrong vaccum line set up when motorswap was done by previous owner and couldn't get it to figured out so I bought it at quite a good deal. thank u for posting all this stuff greatly appreciated. now to figure out what I should do for down pipes? can I just remove cats without having to get any sort of tune

Reuben

10-31-2022, 09:04 PM

I would advise against downpipe mods. The system is sensitive to overboosting. Honestly, do not mod it. Get it running mint, and you wont want to. If its not enough, TT isn't for you, and you should single convert.

Honestly get her running mint first, then reevaluate.

s0abh4

11-01-2022, 12:51 AM

that's all I needed to here it'll stay they way it is . can't believe how quick it is from a week ago . thank u again for your knowledge!

austinask

11-11-2022, 09:42 PM

I picked up a 1997 GTB in New York State about a month ago and have been getting a few things done to it before winter. This is the best information I have been able to find on any forum about our cars.

So far I replaced the primary VF20 turbo, sourced a brand new unit from Compact Motorsports (NZ).
Installed a urethane pitch stop mount
Fitted aftermarket 02 WRX wagon suspension while I get the Bilsteins rebuilt
Will be installing Whiteline bushings all around this weekend
Will be fitting a GFB T9220 diverter/atmospheric valve also

I do have a couple of questions. My car is an automatic which is meh at best with the VoD. Would doing a MT conversion be beneficial enough just to use the vehicle as a DD? I would be fine doing a “simple” 5spd swap and not searching for crazy power if that will make the crossover from 1 to 2 turbos less pronounced. Otherwise I will probably do a single turbo conversion of some sort along with a 6spd MT swap.

The other is that my car came fitted with the STi front strut brace and an STi badge above the glovebox, does this badge signify any differences about my car? A vin search didn’t tell me anything special other than being a less common spec. The strut brace also only attaches to two of the top mount studs, which I found odd compared to others I have seen photos of.

Thanks in advance!

3919

Reuben

11-12-2022, 06:11 AM

That badge actually belongs to no car, only way to get them was buy buying them in dealerships, to my knowledge. But no, there was no STi 2nd gen, only generation to not get an STi or tuned by STi model, making just regular *manual* GTB’s the closest you could get. Manual GTB’s have a few components in common with V3/4 STi’s, including cams, and transmission, and bits in common with 20K’s like the yellow injectors and orange MAF, larger throttle body. Auto GTB’s have none of that sadly, their common single turbo equiv is the smooth cover 20G’s from V3/4 WRX wagons/autos.

The STi front strut brace is neat though, that was the STi catalogue part for your car, very neat and relatively rare. Not to be confused with the similar impreza one that’s not rare at all, so def be proud of that piece! I looked for one for years in NZ, never found one, so had to import one from japan.

Also sadly i must inform you that autos have the lesser vod. And the TCU’s know how to shift to avoid it most the time, unlike our manual driving simian hind brains.

And last bit of bad news (gee not good for you this post). But to my knowledge manual swapping and retaining TT is not possible, unless you had a full manual facelift GT donor car to use the loom out of. As the facelift auto GT/GTB’s used an intergrated ECU/TCU deal, where the TCU is in the ECU, and so theres an aweful mess of wiring going to a singular ECU plug not common with any other car. You can manual convert without a donor loom, but you would do it by using a standalone like link or haltech, and you’d be forced to single convert, as no standalone does TT. Not even haltech, who said to another member that they do, and once said member had bought it, and gone to set it up, found that the haltech rep was talking out his ass. They had their wires crossed so to speak, the haltech did indeed plug into his manual 3-plug loom, since its common with V3/4, but the rep had no idea that the TT has an additional 7 solenoids and sensors you need to control very specifically.

So long story short, if you want a manual, VOD will be worse, and to get it you need to buy a manual GTB.

Sorry im posting this from my phone where ive disabled autocorrect cause its just gone insane, so theres probably a few errors in there ��

austinask

11-13-2022, 07:45 AM

At least I can say the strut brace is cool!

I really like how much character the TT has, it was part of my reason for getting the car. It is hard to get a clear picture of how the car runs. It was clearly very neglected in its first 25 years. The cold start piston slap isn’t as bad as my 9-2x Aero had but that car was pushing 260k kms. What it seems like is that the car doesn’t boost properly until I’ve done a fair bit of highway driving, I’ve yet to connect a boost gauge to see what’s going on.

Telling myself that if the engine blows up then I’ll have to make a decision on what to put in it.
If I were going to manual swap and try to retain TT I had expected I would need to find a full bulkhead harness as well. I think if I found a full front cut of a manual GTB that would be the most straight forward way. I did find a NOS harness available but the juice isn’t worth the squeeze.

I’ll admit It does sound like stand-alone and single twin scroll turbo is the way to go, just a shame to lose some of the quirky character of the car.

vanislebh5

04-15-2023, 09:39 PM

Hi , I have a 97 VDC BH5 GT , where is the evap solenoid and canister , also been searching for months on the reason for the engine to cut down while accelarating hard ,or under load.... boost gage reads normal boost pressure, new plugs , cleaned all solenoids in the black box, no codes on my reader

need to clean the evap system as I get pressure when I remove the gas cap

Thanks !

Reuben

04-17-2023, 09:43 AM

vanislebh5

05-04-2023, 10:36 AM

Solenoid is on the manifold somewhere. Behind the power steering/alternator on the rev-D, cant recall for the rev-A.

canister lives under the back bumper.

Never once have I heard of these needing a clean, but if you find a snapped nipple on the solenoid, that’d be a smoking gun for your diagnosis.

Let us know how you get on.

Well , found the solenoid, trying to remove the hoses and what a surprized the plastic nipples broke, did a temporary fix and cleaned it while it clicks open with the green connector under the dash is connected.

will put the new one when it gets here ,

subyroo

05-04-2023, 10:30 PM

Has anybody been able to lay their hands on a Workshop Manual for the TT's, specifically a 2002 Subaru Liberty B4 twin turbo?

duncanm

05-23-2023, 06:08 PM

Has anybody been able to lay their hands on a Workshop Manual for the TT's, specifically a 2002 Subaru Liberty B4 twin turbo?

from clubsub.. try here: https://drive.google.com/drive/folders/1-6hgvSh7lhaVqIKCSOJsbIKPv1LSNn6m

TT is just an engine variant in the BE/BH manual.

vanislebh5

05-31-2023, 12:48 AM

Solenoid is on the manifold somewhere. Behind the power steering/alternator on the rev-D, cant recall for the rev-A.

canister lives under the back bumper.

Never once have I heard of these needing a clean, but if you find a snapped nipple on the solenoid, that’d be a smoking gun for your diagnosis.

Let us know how you get on.

Well , install the new part, car behaves the same, next test is to test fuel pressure ,

vanislebh5

06-10-2023, 10:58 PM

Well , install the new part, car behaves the same, next test is to test fuel pressure ,

at idle 30ish psi, with open throttle 40ish...

will change the pressure regulator and see

G531

08-04-2023, 10:06 AM

I have a 98 gt-b with the EJ20R making some bottom end noise. I have also located a pre facelift Ej20H. If I just use the longblock and retain all of the manifolds/turbo/everything else from the R, this setup should bolt in and work fine due to the same compression ratio correct?

Reuben

08-04-2023, 11:04 AM

For others watching:
Early 20H 8.5:1
Late 20H 9:1
B-rev 20R 8:1
C-rev 20R 8.5:1

So yup, same comp thankfully. Yeah as long as you retain the manifold from the 20R (and thus the yellow injectors and vacuum layout), it’ll be fine. Early 20H’s don’t flow as much in the heads, and have weak cams. I suggest you swap the 20R cams into it to at least help get a bit of that 20R power back. Great thing is you wont have to re-shim as early 20H have hydraulic lifters, slap em in and go.

Be super careful pulling the manifold off, pry the PCV off the block before pulling the manifold up. If you have to sacrifice the F-pipe, so be it, they are still available new, I just bought 5 for my stock at home a few weeks back. Sacrificed one doing a 208 manifold the other day for example.

10w-40 or thicker oil is advised for early 20H, Full synth naturally. Minimum 98ron/93freedom-octane on the stock ECU (20R ECU’s are super spicy with their timing).

G531

08-04-2023, 11:51 AM

Thank you for the quick reply, Id love to just go apples for apples and swap in another 20r, but im having a very hard time finding a replacement. I know I can got the full rebuild route too, but time and money are key in this project.

Reuben

08-04-2023, 06:23 PM

For sure keep the heads. You can slap them on an EJ207 short block and you’re basically done.

vanislebh5

10-18-2023, 10:32 AM

changed my fuel pressure regulator on mine, the car starts easily in the morning, I had done a fuel pressure test and it was not keeping pressure over an hour before. I still have the car jerking if I am pressing on the gas slowly, but no codes ! If I press full throttle , it wont jerk, but has some hesitation . boost gage install and I get full boost, I have the JDM app on the android radio, fuel pump duty goes to 100 % , spark plugs were changed ,

By the way the car is automatic, If I press on the power button, full throttle the car goes but still feel like there is slight hesitation . gas mileage is pretty bad 12.5l/100 km city driving , 11 on the highway .

I am wondering if the coils need to be changed . car has only 92k and its a 97 ej206 ,

Please Help !

Thanks

duncanm

10-23-2023, 12:46 AM

Very hard to diagnose with that description, but I think you're looking in the wrong direction.

The hesitation, and the mileage you report in your other thread, both suggest it is running rich. Do you see black smoke when on the throttle?

You need to find why its over-fuelling. What does the lambda do at idle and cruising on your real time OBD? Does it have a bodgy aftermarket interceptor box, or a reflashed ECU?

Check the simple stuff.
- AFM good? - look here first
- O2 sensor good?
- in-tank fuel filter been replaced (maybe its crap in the system causing surging)

(ps: I'm pretty sure the fuel pump duty cycle has three settings: low/med/high. Low is only idle, medium maybe a little throttle, and high everything above that)

vanislebh5

10-24-2023, 10:47 PM

duncanm

10-24-2023, 10:59 PM

Don't trust the codes on something so old, they're not nearly as diagnostic as they are these days - especially with things like the MAF.

jeb.

11-09-2023, 10:31 PM

Reuben thank you for all this solid info. My wife recently got me 1998 Legacy GT TT Touring Wagon and I am in love. I wanted a RHD car for ages and now it's happened and I couldn't be happier with my choice.

So I've been driving my BH5 a few days a week to work and around town and the radiator separated at the seams.

Any recommendations for a replacement? I was thinking of going with an all-aluminum and adding an external ATF cooler.

3991
3992

Reuben

11-10-2023, 04:48 AM

I actually prefer the plastic ones. They’re typically lasted me 20 odd years before going, where’s the alloy ones I’ve tried have all died within a year.

Quality control is the issue, not material.

External cooler is also a great idea, purely from a serviceability standpoint, making it easier to pull the rad for certain jobs like cambelt and engine outs. Be aware it will affect how long the trans takes to get up to temp.

vanislebh5

11-18-2023, 01:39 PM

in the crazy research I have done so far to find the issue of the hesitation , I wondered if the VDC was acting up. So I found that that by adding a fuse on the FWD empty spot actually bypasses the VDC. I am not sure , but it seems to work better now .

Does anyone has made a switch linked to that fuse so you can turn it off for snow drifting ?

Thanks

Stickiestbuds

12-28-2023, 12:34 AM

OP says there is a vacuum diagram for 3rd gen with VDC but I don't see one. Anyone have it? I'm just trying to confirm my lines on the RH side (around BOV) are correct. My car is making about 5/6psi on primary and 8-9 post VOD, trying to figure out why. There is a cluster fuck of tees and restrictors (and boost gauge) coming off of the inner BOV port, the outer one just goes to what I'm guessing is something to do with VDC.

Reuben

12-28-2023, 01:24 PM

No the VDC diagram is the only one I’m missing. But yes, it is factory to have a mess of tees off the BOV like you describe. Whether or not they are correct currently for you I can’t say.

jeb.

07-10-2024, 06:35 PM

Just dropping in with a question. Has anyone here replaced their header (Fujitsubo) on this engine? Is there an aftermarket option for the up pipe? I just installed a Fujitsubo exhaust and Kakimoto straight pipe, but was thinking of installing a header as well. Any tips?

Reuben

07-10-2024, 07:52 PM

jeb.

07-27-2024, 07:03 PM

You are limited with what can be done, as you need to retain the secondary exhaust valve. If you change with diameters too much and affect how the turbos spool, you can also get into code 66 territory.

I think there are some aftermarket ones that exist, that retain sequential, but most you’ll find delete the secondary exhaust valve and are designed to convert the car to twin parallel. So just be mindful of that.

Generally speaking, don’t. Don’t mess with too much, the sequential system is moody and susceptible to changes like this causing issues. It’s safer just sticking to cat-backs etc.

Thank you for the great information. I wasn't fully aware of the sequential system's mechanical parts. I'll stick to my straight pipe and exhaust. I'm hoping the EJ206 lasts for a while. If and when it goes I want to drop in a full STi swap.

I bought a set of red Subaru 4-pot calipers, power stop rotors (all around), power stop pads, and stainless steel brake lines. This should be the last upgrade for a while.

4066
Enkei EKM3 wheels installed
4067
Sourced a double armrest
4068
Finally found a carbon fiber scoop trim(not installed permanently yet)

elVatoTaco

11-07-2024, 05:52 PM

I'm looking for aftermarket front down pipes, where can I find a list of compatible parts because I'm having a hard time finding anything before the 1998 model years.

I have a 1996 Legacy GT Wagon

Reuben

11-08-2024, 06:58 AM

I'm looking for aftermarket front down pipes, where can I find a list of compatible parts because I'm having a hard time finding anything before the 1998 model years.

I have a 1996 Legacy GT Wagon

Contact a good fabricator, and go custom.

Waynos

12-15-2024, 12:58 AM

G'day friends, I joined this forum specifically to say a huge thank you to Reuben.

As I read through his extremely thorough post, solving some problems I had and getting schooled on a dozen other things, I thought, shit this dude writes like a kiwi, then sure enough, I see the Queenstown location. Coincidentally I'm on the same Island, north of there in Woodend.

Then I see that he has posted 12,000+ times! Such good karma. Amazing. I am humbled by that.

I think man, if you read this, putting a paypal buy me a cuppa link at the end of your posts would be totally acceptable. I would be happy to.

All the best every one. Waynos

vanislebh5

01-20-2025, 09:59 PM

@ Reuben

I have the one that I should of not bought according to your info thread , 1997 BH5A with VDC ... :smt085 ,its actually my girlfriend's car , so it is fine for her

Do you have the info on the pills ? for the vdc model

Thanks

Raugur

04-10-2025, 10:22 AM

1997 EJ20H dreaded intermittent stall/go/power loss….

Changed fuel pump, plugs, fuel filter…. Thinking 02 sensors?

1. Where do I find part # for our JDM parts?
2. Best source for these parts?

Thank you

Chuckgf8

04-12-2025, 12:26 AM

Amayama.com use your chassis number to get the correct parts

bmart

05-05-2025, 10:34 AM

Great info. Thanks!

I just did the hose 10 mod the other day on my B rev BH5 with no change from my seat of the pants. I see that you say don't do it. Guess I should undo it?

Also planned to do the .8mm hose 1 mod. Is that also verboten?

Thank you!

Jerryd83

06-13-2025, 09:05 AM

Hey Reuben I have a 97 Legacy with a EJ 20R TT and as I was driving home the other day it started acting like it was missing and as I slightly pressed on the throttle it would clear up but but by the time I got home it was barely pulling itself. I've changed the plugs, coils, cleaned the throttle body, new fresh tank of 93 octane, and cleaned the MAF but nothing is fixing it. I've also used your diagrams and checked all my vacuum lines but found no problems. There's also no check engine light on. Anything you can do to help would be greatly appreciated.

Thanks,
Jared

Reuben

06-13-2025, 07:53 PM

When o2 sensors fail, often they wont throw a code, and will present as unresponsive/lack of power until you floor it, then the car will run mint. So just light throttle issues.

So that was my first thought, but you describe it as developing rapidly, and barely running when ya got home, which suggests to me it’s probably mechanical in nature. Do a compression check maybe, and a smoke check of your intake/listen out for that tell-tale hiss of an intake leak

Jerryd83

06-15-2025, 10:04 AM

Reuben

07-07-2025, 06:48 PM

Hehe, google seems to be indexing this thread good. I just got featured by MSN lol

https://www.msn.com/en-nz/news/other/subaru-made-the-world-s-only-twin-turbo-flat-four-it-was-madness/ar-AA1I1SYp

jeb.

07-30-2025, 09:40 PM

Hehe, google seems to be indexing this thread good. I just got featured by MSN lol

https://www.msn.com/en-nz/news/other/subaru-made-the-world-s-only-twin-turbo-flat-four-it-was-madness/ar-AA1I1SYp

It's been my bible since I picked up my BH5. I just tuned it with a 93 octane base map from Lambda. Whiteline bump steer kit and rear control arms next.

jeb.

08-31-2025, 11:47 PM

Hehe, google seems to be indexing this thread good. I just got featured by MSN lol

https://www.msn.com/en-nz/news/other/subaru-made-the-world-s-only-twin-turbo-flat-four-it-was-madness/ar-AA1I1SYp

Reuben are you still active here?

I’m looking for a recommendation for a replacement turbo inlet pipe and a fuel pump. My GTB is becoming a bit hard to start and in thinking it’s the fuel pump. Also the inlet pipe is a bit mangled.

Last thing is a catch can or air oil separator. I have oil seeping from my intercooler and think this would help.

Thanks!

Reuben

09-01-2025, 09:38 AM

Sure am.

Fuel pump, easy, DW250. Done.

Inlet pipe, ya stuffed. You may still be able to the silicone ones from china, but they are designed for Rev-D BH, with the larger turbo inlet, so it requires getting some silicone the size of your turbo inlets, then basically use that to double up and adapt the BH pipe. You will also lose the IACV hose if fitting to BG, which will require a custom solution (remember IACV air must be metered with stock ECU’s). But I think those silicone intakes might no longer be available. :(

You might need to get creative. Fab work time.

Hard to start could be many things. The MAF sensor is normally where i start. If BH, easy, just grab off partsouq/amayama. If a BG purple or orange sticker… maybe consider buying a link ECU.

jeb.

09-02-2025, 11:22 PM

Reuben

09-03-2025, 09:36 AM

Fuga350GT

09-07-2025, 06:35 PM

I found a YT'er that posts the repairs/maintenance of her two BH's - it appears maybe she has a BH GT VDC(version maybe?) and then also a nice blue S edition. An older master mechanic-son that does videos apparently with his younger female protege, said the BP's O2 sensors can be used as direct replacements on the EJ206/8 motors. And went on to install it and it apparently worked fine. Not sure I've seen that mentioned anywhere before, but then again just getting my feet wet with this car/engine, specifically a EJ206 with about 122k KM - I recently imported a '00 etune. The nav system and some body work is a little worse for wear, but mechanically so far so good. drove the vehicle home from the port - super icey cold AC. It appears to have likely been a pretty close to fully loaded etune version back in the day, has a '001' Fujitsubo exhaust ....even with a functioning cargo fan in the rear. A good amount of service records, I even confirmed they replaced the gauge cluster via a recall with a work order.

Two quick questions hopefully:

I am updating the tune with ProjectLambda for our crappy 91 octane here, I was also considering replacing the ignition coils with plugs, should I only be looking at OEM for these replacements you think?

Also, it appears the timing belt was changed at about 50-60k KM's but that was also back in like in 2007/2008, so seems like age wise it was a while ago. Should I be considering getting that done as well?

Reuben

09-07-2025, 09:18 PM

Regarding o2, if this is true, it is only true of Rev-D’s. Remember, engine codes mean nothing on their own, you need context such as year, model, etc, to make any usable sense of them. For example, turbos, triggering, compression, sensors, and injectors all change on the EJ206/208 through the years they were built.

Rev-D is in reference to the applied model code of the car, it refers to the 4th digit of the applied model, which implies model year, (not build date, but specifically model year). So Rev-D’s are MY2002 and MY2003. Another way to think of it is Rev-a/b/c are same generation as v5/6 GC, rev-d is same generation as GD

A note on e-tunes. This just means they are a long gearing car. All Rev-D’s are E-tune as well, prior rev’s it was separate trim level.

And how do you mean by replacing coils with plugs? BH/BE’s already run what americans call “wrx coils”, they are a good and adequate coil for 99% of builds. They are not known for failing like pre 96 coils are. Plugs, you must stick with platinum/iridium/rutherfordium plugs. As mentioned above.

Belt wise, yeah pushing on 20 years there, def change. Im ok with ignoring the 10 year limit, up to a point. 20 years is pass that point :lol:

Fuga350GT

09-08-2025, 01:30 PM

Regarding o2, if this is true, it is only true of Rev-D’s. Remember, engine codes mean nothing on their own, you need context such as year, model, etc, to make any usable sense of them. For example, turbos, triggering, compression, sensors, and injectors all change on the EJ206/208 through the years they were built.

Rev-D is in reference to the applied model code of the car, it refers to the 4th digit of the applied model, which implies model year, (not build date, but specifically model year). So Rev-D’s are MY2002 and MY2003. Another way to think of it is Rev-a/b/c are same generation as v5/6 GC, rev-d is same generation as GD

Ahh right! Has to be RevD based on model year. I gotta keep that in mind.

Does that mean JDM Rev D's are true OBDII ?? Or is something slightly different?
The RevD appear to be tunable through SSM and more or less freeware/shareware out there.

Do you know of any options out there like that to tune the Rev A - C's ECU's?

And if I understand they are similar to OBDI but not exactly the same?? But not sure of that.

Reuben

09-08-2025, 06:39 PM

All JDM BE/BH’s are OBD-II, but you are right, they are different to international. The early A/B/C is what youll see called “J-OBD”, and regular scan tools will not be able to communicate, or only get codes and nothing else. D’s though are closer to worldwide OBD-II and should have more universal data. But you will still get better results with a J-OBD scanner.

If you want a scan tool, get a launch off ali express, launch have an official store on there, the CRP129 is a great tool for these J-OBD JDM cars.

Tuning wise, all BE/BH TT’s are tunable, but once more, A/B/C cars are trickier. I can not help here. There are guys in NZ that tune them, but they guard their secrets. You’d need to find what tool they use, and what ecu definitions they are using. Be aware there can be like 10 different definitions for a given model year based of trim, trans etc etc.

The Rev D cars are kin with the Version 7 bug eye GD, so its much more straightforward. But still beyond what i have ever done. I work for Link so obv my recommendation is gonna be get a link!

jeb.

09-15-2025, 09:41 PM

Reuben,

Couple more questions:

Any recommendations on an oil catch can setup for the EJ206? I have oil pooling and dripping out and causing some smoke.

I want to do all the work at the same time when I get to installing the silicone inlet.

Also, how can I buy you a cup of coffee or a brew? :blob2:

Reuben

09-15-2025, 11:12 PM

Catch can setup, you can use any single turbo setup made for WRX, so long as they aren’t designed to sit where the primary sits :’D Well, I say that but I mean earlier WRX, with the single crank case breather.

The PCV system is essentially the same, with the PCV valve teeing into the crank case breather, and the rocker breathers being separate. I recommend the twin catch setups, where the separation of the rocker breathers is maintained.

Essentially ya just want crank case to catch, back to stock location and teed to pre tubo and PCV, and rocker covers to catch, and then back to pre turb. Im not totally a fan of block to catch to atmosphere, but it does make for tidier installs.

And if you ever make ya way to NZ, ya can buy me a beer in person ;)

nuclearDEMIZE

10-01-2025, 09:45 PM

Hey Ruben, I'm wondering if you can help me diagnose an issue I'm having. I imported a 2000 RSK from Japan with 28k km on it. It idles really rough and when I'm accelerating its very surgery/jerky. I did a fuel pressure test on it and without it running it's about 40 psi. While running it drops to 30 something but I'm doesn't really move even when the engine is idling really rough. I bought a smoke machine to test for vacuum leaks and nothing obvious.

I installed a boost gauge and I get up to about 9 psi max on both turbos. Also if I'm cruising in 3/4/5 or any gear but those are cruising gears the car runs really smooth with no boost. Once the Guage goes to about 3+ psi I can feel the motor start running really rough. Also if I just stomp it out and try to run the gear out it doesn't really have enough to push to red, at least I don't dare to hold it. Usually it stays running while idling but occasionally it dies. It typically starts right back up. I've noticed that if I keep the boost at about zero PSI, the car runs smooth

Reuben

10-02-2025, 02:43 AM

Very interesting. Have you checked that the fuel pressure regulator has its vacuum hose in good shape? Maybe check the fuel tank is clean and not rusted out. With that low mileage at this age, its likely its done some long stints without running.

I would maybe consider getting a diagnostic run with a wideband shoved in the back like they use on dyno’s, to see if you’re going lean or rich. Maybe talk to your local tuner rather than local mechanic.

Other things to check, i know its only got low k’s, but just in case any muppet has put large gap standard/copper plugs in it. They must run PFR6G or PFR6B or BKR6EIX plugs. They should be gapped between 0.7 and 0.8mm. Though ignition issues normally present like cuts, they arent a smooth lack of power.

I would also recommend just getting a brand new genuine MAF sensor. Though in this example im not as convinced it has anything to do with your issues like I normally am (i’d say MAF is the most common failure on these cars). I would leave that till after you’ve exhausted the other options.

By the sounds of it, my guess is fuelling over anything like boost control or TT solenoid operation.

I’ll say it’s not related to o2, as o2 only affects cruise, not under boost, which is the opposite of where you issues are.

What a fun one! Lucky you. If you find rust in the tank, you’ll have to pull your injectors.

nuclearDEMIZE

10-04-2025, 05:01 AM

So the first thing I tried was to replace the MAF sensor. I made a post on reddit and someone mentioned their car was doing something similar and it was the fuel pressure reg so I bought a new one of those while I was in Japan buuuuut I got pretty deep into it and couldn't get it out without pulling the manifold. I think the hoses looked good going to it. I should look at the fuel filter and see what it looks like.

Unfortunately I live on Guam and dont have access to a reputable tuner. I'll double check the spark plugs and gaps, that's a good idea. It definitely feels like its cutting out. Like it will jerk surge pretty hard sometimes.

No CEL and I bought a specific reader for JDM cars to see if there was anything and it was clean.

My original post was from mobile so now I can be a bit more specific. Occasionally and very rarely the car runs okay. Like it feels like it will make 80-85% power and when I'm shifting from 2-3 it will pull decently (when it does I can kind of hear the intake) Most of the time it's idling very rough. Then when I put it in first it will sometimes do okay, seems to do better if its a bit cooler although Guam is always warmish. Anyway, 1st will be jerky and surgy, so will 2nd, third is okay but really if I keep the boost right at 0-3 psi is where it runs the smoothest. And honestly its really smooth here. The same with 4/5, I can literally feel the exact point on the pedal where the engine feels really rough, like it feels like its not firing on all cylinders but IDK. Sometimes in like 2 or 3 if its lower RPM and I giver her the beans (floor it) it will be shaky and lagging and once it awhile I can hear it back fire. I run 91 octane (US). It will usually stay running albeit very rough but occasionally it will die, it always starts relatively easy when that happens.

I really appreciate you taking the time to give some good troubleshooting options.

Reuben

10-04-2025, 06:46 AM

Yeah these cars often dont pull CEL. Very old school OBD-1 style ECU’s that only spit codes when something is a dead short, or open circuit, with very few codes for misbehaving but functional sensors.So disgnostics often take an old school approach to figure out.

Having replaced the MAF is good, its worth while, removes all doubt about it being the cause. We can now look at more exotic failure modes these cars suffer.

One of my favourites i’ve seen at least 5 times, which does present symptoms like what you’ve said, but is mist notable at idle, is the alternator. Whip the belt off and start the car, you’ll note and instant and complete fix if this is the problem. The fault is this particularly generation of alternator on these cars can fail in a way that spews out EMF. The crank and cam angle sensor wiring pics up the interference and it makes the signal to the ECU rough as guts (they are reluctor style so very vulnerable to electrical noise). The ECU will misinterpret the signals and ya injection and spark events can go all over the place.

Other things you csn insoect is the TPS voltages, see the discussion above.its very explicit how you must set the voltage, it’s impossible to set by feel, so if anyone has touched the semsor its possible its off. If your scan tool can read live data from the car this is trivial, if not, its s multimeter job.

And lastly, if the manifold has been off, yes its possible theres vac leaks etc. But you said you smoked it, so yeah, maybe not that.

Oh, and yes i have seen failed fuel pressure regulators. I would continue with this job and replace it. Sorry to hear its a manifold off job. Refer to my videos on my GT project for tips on stuff like that. Dunno if i pulled the mani on that actually? Hmm. But yes, you must be exceptionally delecate with the PCV into the pre turbo inlet pipe. The trick is to sacrifice the F-pipe tee piece and replace it with new.

nuclearDEMIZE

10-04-2025, 04:23 PM

Yeah unfortunately nothing I have will show real-time data. I'll try some of those easier solutions first and just keep chasing the gremlin. I really appreciate you taking the time to troubleshoot and write all that out. If I end up finding out what it is I'll post an update.

Reuben

10-05-2025, 07:40 AM

Launch brother.
CRP129

Their official store is on ali express. They have 0 problems reading live data on what they call “JOBD”

Les.S

10-09-2025, 12:40 AM

Hey Reuben thanks all the info! I got myself a bg5a a few months ago and code 66 was doin my head in. Was checking the solenoids in the spare bbod and noticed that hose 5 was in the top bank and then saw 2 was down lower. Checked the one in the car and it was exactly the same. Used your diagram and got all of the hoses sorted and no more code 66.

Reuben

10-09-2025, 07:58 AM

Results! I’ll have to look at the diagram and figure out what that would have been causing for you.

Side note, I recently found, as in like 2 weeks ago, that there’s some oddities with A-rev. My JDM service manuals from 1993 show a different vac layout in the BBoD to what i’ve published. But I’ve only ever seen what I’ve published in the wild. Turns out some of the photos in the manual are from a pre-production car (makes sense). My guess was the vac layout in the book is pre-production, and didn’t get updated even though the part did! But it is possible some early early production cars, or maybe 93’s in general had the BBoD thats in the manual.

I’ll have to look at it again and document the difference for you fellas! I just remember it not being an inconsequential difference (vacuun lines are tricky alright lol)

Fuga350GT

10-19-2025, 04:00 PM

Oh sweet! Good they still make those intakes. That will fit, but you will need to do the trick with the turbo inlets as they well be a smaller diameter. Easy done.

Edit: did i see with this listing you can choose inlet size!? Neat! BH A-rev will be the smaller size.

And be thankful you have the BH MAF, they are cheap as fuck compared to the BG ones, before theBG ones were discontinued that is. Such is life.

Goes without saying if you dont know the age of your plugs, do them too. You must use Iridium or platinum. The cars complain greatly if you use standard nickels, or “copper” as the plebs say. PFR6G, PFR6B, or BKR6EIX are all valid usable plugs. Do not use -11 suffix versions of those numbers, thats the larger non turbo gap. Do not use 7 heat range, stick to the 6’s.

For some of these aftermarket silicon turbo air intakes - I see two different sizes mentioned, a 50mm/50mm and a 46mm/63mm measurements - which go to which versions of the EJ206/8's? I'm looking for the Rev C the vf32/vf33

And I see some of these listed on alibaba and ebay - doesn't appear NOS OEM versions are still available elsewhere - does that seem to be the case?

Reuben

10-20-2025, 03:21 AM

The genuine part has been NLA for quite some time.

I believe the Rev-D was the one with the larger secondary than primary, so my GUESS is the 46/63 is for rev D, and the 50/50 is for all other BE/BH models.

Fuga350GT

10-20-2025, 02:12 PM

Thanks for the info!

This isnthe inlet pipe I had in mind:
41704171

I'll pick up a DW250 this week. The MAF I'll get from Amayama.

I'm not going to be able to convert to single turbo since I'm in the US without donor vehicles available sadly. For reference I have a REV A 1998 Auto.
jeb. which seller did you pick this up from? Thoughts so far?

The genuine part has been NLA for quite some time.

I believe the Rev-D was the one with the larger secondary than primary, so my GUESS is the 46/63 is for rev D, and the 50/50 is for all other BE/BH models.

Copy, that seems right: I get part No's as 14462AA201 For Rev A - Rev C & 14462AA272 for Rev D when I search by chassis numbers. Have we heard of anyone else on the forums purchasing and using these chinese silicon versions with results?

Also, any good/recommended type of lines suggested for the replacing the vacuum lines in the BBOD and connecting throughout the motor?

Tlocken

11-21-2025, 04:25 PM

I got a 2000 GT-B E-Tune and I’m having a hell of a time getting finding new down pipes for it any suggestions? I've found some at Scoobyworld but i'm looking at almost $914.75 usd before shipping which is a bit steep

Fuga350GT

12-17-2025, 06:53 PM

Reuben

12-18-2025, 08:44 AM

At this point really your only options are getting second hand aftermarket japanese pipes, or getting something custom made.

Keep in mind if you change the spool characteristics of the TT’s too much, its possible to run in to code 66. But my advice here is send it, and cross ya fingers/deal with it if it does pop up.

Good news is it turns out you can run sequential TT now on a Link ECU, thanks to yours truly pesting the engineers there. We just need to validate it on a few cars. For now it’ll just come in the form of a tweaked base map, and instructions on how to wire it. In future i hope to get it implemented as a feature. (I work at Link now btw lol, didn’t take me long to get TT going lol).

Fuga350GT

04-03-2026, 05:16 PM

Reuben

04-04-2026, 09:58 PM

Fuga350GT

04-07-2026, 11:12 PM

I’m going to guess that no, the Link can not output OBD based emmisions data for your local inspection.

What runtimes do they measure for smog?
Does the early J-OBD have that data, can they even connect to the stock ECU?
And is the vehicle not exempt from it due to the nature of its 25+ year import?

I know some states they only want to look at certain numbers like lambda for exampme, which you will be able to display with link software, so it may require sweet talking/getting friendly with local inspectors so you’d be allowed to use the Link software in leu of OBD, bet depending on state rules that may or may not be allowed.

I’ll ask the engineers at work about OBD-II.

Seems to me if that was doable, an updated ECU could be a solution to some of us in weird bureaucratic voids of jurisdictions. Specifically Clark County(Las Vegas proper), is one that is truly dumbfounding. Only 1996 or older MFG'd vehicles can be tested with the tailpipe sniffer. If a vehicle is 1997 or newer it must, no exceptions, be done through OBD2 port, yes, even if it is does not have OBD2 capable port. I haven't done followup research but I'm thinking all USDM vehicles for the most part must've been required to be OBD2 compliant as of 1997 or newer. Unfortunately that little silly statute, with what seems to be an arbitrary cut off date was made without foresight to the current predicament many of us are now in.

I'd imagine the various regulatory bodies with oversight of the environment/pollution control are required to publish what and how the emissions interface works, since equipment manufacturers are also making the software & interface devices to sell to the certified but still privately owned Smog Test providers.