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

[austinask]

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!

[Reuben]

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]

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]

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]

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.

[vanislebh5]

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]

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]

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/folde...JsbIKPv1LSNn6m

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

[vanislebh5]

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]

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]

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]

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]

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]

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

[vanislebh5]

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]

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]

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)

Hey thanks for the reply,

MAF is good, not getting any codes ...
OA is good , not codes
Maybe there is crap in the fuel system , I wonder if the pump is just slowly dying ?

Was driving in the pretty bad Vancouver Island November rain , it seemed worst , I am tempted to change all 4 coils ..... damn BH5 !

[duncanm]

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.]

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.

[Reuben]

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]

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]

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]

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.]

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]

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.

[jeb.]

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.


Enkei EKM3 wheels installed

Sourced a double armrest

Finally found a carbon fiber scoop trim(not installed permanently yet)