Member Profile - James' GT spec B Wagon - GTB013

[jamescd]

Alright, another update.

I know I mentioned subframe bushes way back when, and I was unsure what I wanted to do. In the end I bit the bullet and got the Energy Suspension (194102G) from RockAuto. Fitment was the usual, I burned out the old bushes and then cut the old bush sleeves and chiseled them out. Push in the new ones, job done.
The rear end also got:
JDM alloy trailing arms
JDM upper alloy arms
Whiteline adjustable lower arms (KTA124, I got these second hand and bought the KSK124 kit to refresh them)
Cusco pillow ball endlinks (684 317 A)
Cusco endlink mount (684 316 S)
Cusco Rear Arm Bracing (680 478 A)
Fresh Whiteline bushes in every spot
-Trailing Arm Front Bush (W63398)
-Trailing Arm Rear Bush (W63394)
-Upper Control Arm Inner Bush (W63396)
-Upper Control Arm Outer Bush(+/- 1.25deg caster adjustment) (KCA399)
-Differential Subframe Bushes (KDT906)
-Differential Moustache Bar Bushes (KDT905)
-Toe Lock-out Bolts (KCA307)





I have also fit a VA quick rack (2.4 turns lock to lock). To go with the rack I installed a Cusco steering rack brace (692 026 A) along with a set of Whiteline rack bushes (KSR207).
In order to complete the upgrade I also installed the u-joint from a VA STI. These are just a straight piece compared to the factory Liberty u-joint which has a built-in rubber damper.



I trimmed the outer tie rods to allow for a better range of adjustment.

I also replaced the Whiteline bump steer correction kit with a new Hardrace kit (Q0796). I also installed Cusco endlinks (667 318 A).



In further suspension mods, I got the Caster top hats for the Shockworks. The new hats move the suspension top mount further towards the rear of the car giving more positive caster.


I also forgot to mention about the transmission mount stuff I added in the last post, but it also crosses over as I bought the Cusco kit which also includes the engine mounts (660-911-SET). I also fit the Whiteline Transmission Subframe Bushes (KDT901).


My old setup had some heat wrap around the wastegate piping where it ran over the C/V boot, I didn't love this, so I have added the Cusco Heat Shield (6A1 047 F)


I have also done some more engine work since the last post.
I didn't trust the AVCS sprockets that I had, so decided to rebuild them.
My top tip is to make sure you have the right tool. A lot of places sell the bit by itself, but the Toledo 301318 set comes with the correct bit and is only about $25 and available at a lot of local tool shops.

The ins and outs of cleaning them is to undo the bolts, take the gears apart (carefully), clean everything, and then put them back together in the reverse order.


The other tip when reassembling is to use a camshaft to line everything up when torquing down the bolts.


As you can see, even from a non-spun bearing engine, these weren't exactly clean


I used this guide, my only other thing to be aware of is that using a pick to split the gears can lead to you stabbing the gasket, and that is not a part that's available separately.
https://www.iwsti.com/threads/avcs-gear ... ng.279112/

The long block is mostly together, most bits are the same in terms of fuel bits and pieces (more is being updated, but I'll mention it when I do it). The main change at this point is that the injectors are ID1700XDS rather than the 1050s that were in there before.


With the timing belt on, it became pretty clear that the timing is a bit out due to changes in deck height and gasket thickness.

I made a degree wheel and piston stop



After taking some measurements on the RH bank, I found that both intake and exhaust were roughly 10 degrees retarded.
I then installed an eccentric idler and that has changed the intake to being 3 degrees retarded and the exhaust to 2 degrees advanced. I am happy enough with this result and at least know what the numbers are. I still need to take some measurements on the LH bank, but it should be close to the RH side.

I also painted my brakes which I have been meaning to do for ages.
Big thanks to Boxer Beauty for making some custom decals for the Alcons


The rear Brembos still need some work as the dogbones put the caliper mounting bolts in the same spot as the aluminium trailing arm.
Ideally I find a set of TbSTI backing plates, but I'm not holding my breath, the other option is custom dogbones that rotate the calipers down slightly to give the bolt enough clearance.

[jamescd]

A fairly big update since the last one (it has been 7 months).

One of the large parts of this build has been the wiring harness.
The ECU Master EMU Pro 8 is at the centre of it all, and I wanted to go all out, making a concentrically twisted harness with DR-25 sheathing. I even did this for the auxiliary harness in the engine bay.

For the interior harness I just opted for spec 44 wire and braid sheathing. While this is also plenty for an engine harness, I wanted the engine bay wiring to be super neat and robust.


Before doing the car side wiring, a lot of the factory wiring was just out, with the whole engine harness being cut off at the bulkhead. With it cut, and the extra wires pulled out from the interior side too, it was time to terminate the body wiring that was still needed. This is for controlling all the body side functions, like the tacho, fans, A/C, brake switch, clutch switch, and a bunch of others.


The engine harness required full fresh measurements, so a rope harness was made to ensure branches and connectors were at the right point.



With the interior all done, the bulkhead could be mounted. I made custom mounts which replace the factory grommets. These are currently resin printed.


With all the planning done done, the harness could be assembled.










With the harnesses done, it was time for the fab.
The intercooler needed new piping, and a new up-pipe and dump needed fabricating.

The up-pipe was fabbed first to get the turbo in place for the intercooler. (no pics)

The intercooler piping was next.






Then the dump. I wanted plumb-back for the gate, as I don't love a screamer on a street car.




This was a lot of after work hours and weekends. A huge thank you to my friend T who did 90% of the fit-up and all the welding. The car absolutely wouldn't be done without his help.

While this was happening I replace the headlight lenses.
Before:


After:


With all the fab work done, the engine needed to come back out so the clutch could go in.


An alignment was also done.



The other thing that needed a lot of plumbing was the fuel system. I picked up a Process West twin pump surge tank which is installed low next to the transmission. This has a pair of twin Walbro 460s.


There was also the flex fuel sensor which needed to be added. I designed a custom bracket to hold the FPR which could then have the flex sensor directly mounted to it.



I also fit an F750 fuel filter in the bay.

[jamescd]

A chunk of this post is copy/pasted from my write up for work about this, just if you happen to have read it ad think it sounds familiar.

The final push to get the car done was pretty hectic. I was hoping to get the car done for the national meet (those I saw there will know that I didn't make the deadline).

With everything pretty much done. A lot of things were very much rushed to get the car done, I dislike my original catch can, and the coolant tank works, but isn't great. These will be fixed, but with the time crunch it was a focus on get it going, not get it perfect.

I was booked on the Spirit of Tas on September 11, and had the dyno booked for the 2nd. Prior to this we attempted to get the car going, but just weren't having any luck.

As mentioned about three updates ago, while preparing this build I had a few issues with finding a set of heads that either worked, or that weren’t total duds. The T20 heads weren't good, but I kept the cams from them, and in the end I got some B25 heads off marketplace.

“Perfect, a set of single AVCS heads, I’ll still be able to use the spicy cams from the original EJ20 heads”

With the B25 heads built, on the engine, and the car wired, my date with the dyno was fast approaching and final checks were happening to make sure everything was working as expected. Generally things were going well, a couple of slight revisions and calibration changes, but nothing too massive to fix. Except for one problem, there was no camshaft position signal.

No amount of settings changes fixed the output, ohming out the wiring confirmed that it was correct, why wasn’t there a cam signal? Both cams were displaying the same problem.

After being up until 1am trying to fix this, with the dyno appointment booked for 8am the same morning, I woke up at 5:30am to try and get to the bottom of this and hopefully still make it to the dyno.

To test that the sensors were working and that the ECU was definitely receiving a signal I pulled the sensor out of the heads and waved a magnet near it while I ran a scope. Lo and behold, there was a cam signal.

So the ECU received a signal, the cam sensor worked, and I knew there were lobes on the cams, so why wasn’t this working?

Then, at 6:30am while staring into the engine bay, surrounded by frost, I remembered that EJ20 and EJ25 cams use a different style of trigger and that EJ20 AVCS heads use a 2 pin VR sensor, not a 3 pin hall sensor (except for the quad AVCS EJ20 Lib heads for some reason).

The problem becomes fairly obvious when you look at the cams. The original cams are the “USDM” style, while the ones I have are the “JDM” style. The paddles on the JDM style are shorter than the raised section of the USDM style, this meant that my sensors which were expecting the larger cams just weren’t close enough to pick up a signal.



At that point I knew this wasn’t a problem that would be solved that morning and unfortunately had to cancel the dyno session.

I didn’t stop though, I had a single spare EJ20 VR cam sensor in the shed, so i pulled it out and went to fit it in the heads to see if that would solve my problem.

It didn’t fit.

The sensor housing was too large, and the mounting hole was at totally the wrong distance to bolt to the heads. That didn’t matter though, after shaving down the sensor so it would fit in the hole and just jamming it in hoping it would stay in position, I ran a couple of jumper wires to the existing harness. With this setup janked in place I ran another scope, and was relieved to see a cam signal.



While not ideal, at least it was a signal.

I wasn’t looking forward to having to shave down every sensor and find a way to mount them, but at least it was a path forward.

Feeling exhausted and fairly defeated I went into work for the day. While I possibly should have taken the day off and slept, I’m glad I didn’t, as within 2 minutes of talking through the problem with T he had come up with a great solution.

“Why don’t you just use a couple of cherry sensors?”

Holy shit, what a great idea, I’m not using a Subaru ECU, I don’t need to be constrained to the Subaru parts bin to fix this problem.

The next day, T’s spare Cherry sensor and a chunk of spare aluminium had formed a test rig to make sure that this plan would work.



It worked.

With the proof of concept done, another cherry sensor was ordered and a better mount was designed.

The next day this was installed, and fortunately both sides worked.




Cam signals were now in the ECU.

This was only the first part of the problem though.

JDM cams have 4 equally spaced paddles on the cams. Unfortunately this means that even with the signals, the ECU can't know where the cam is in relation to the crank.

How does Subaru deal with this?

They have a third cam sensor on the back of the AVCS gear. This has a pair of teeth that mean the ECU can know where the engine is. This meant putting in a third sensor, which there wasn't wiring for, and which I didn't have a bracket on the heads for.

Fortunately, there was an off-the-shelf bracket available, and being a VR sensor a single dual core shielded wire ran from the bulkhead fixed the wiring side.

This fixed the problem, the car now ran.

I had well and truly missed the dyno and ended up taking my mate Seb's car to the National meet.

[jamescd]

Once back from the national meet, I booked back in for the dyno.

I had a couple of weeks before then, so I did a couple more things that needed doing.

I gassed the A/C. I was worried it might not work given the system was open for 4 years, but it works great.


I installed a PDM for controlling the two Walbro 460s in the surge tank.


I designed and 3D printed a mount for my Powertune dash.


I also installed eyelids.


The dyno day came around and the car performed great!




This was just a run-in day, so lots of load and just holding the engine at rpms to get heat into the rings. The dyno tuner and engine builder had a long conversation about break-in, so I am deferring to their expertise.

Even with it just being a run-in day, the car happily made 212kw. This is a great result given it is on conservative timing, wastegate boost (15psi), and only revving to 5k rpm.

I have another few thousand km to do before I go back put some ethanol in it and turn everything up, but I am loving having the car back on the road.


I will do an update to my build list at some point soon, as there is a fair bit that is different.

[Ric]

That is amazingly impressive, and well done diagnosing the CAM sensor problem and finding a workaround!