IT BEGINS
It started with a lot of research. I was driving a C5 Corvette and while the Ls1 engine was phenomenal, the rest of the car sucked. Issues such as cold solder joints breaking inside the ABS computer causing faults, torque tube bearing going out (whole driveline has to come out for this repair), and many other odds and ends failing really started to turn me off. I needed something reliable but still fun to drive and modify. I hated Subarus because of the stigma they carried but couldn't help falling in love with the driveline layout and Japanese reliability. I anticipated many road trips as well and saw the need for a wagon, so I settled on an 06-07 "hawkeye" wrx. If Subaru can do one thing, it's make great wagons. When I started the search, my budget was around 12k for something with 100k miles or less. About three months into my lazy search, a buddy called me from carmax saying he'd just got a nice one on trade in. Skeptical about why someone would trade one of these cars into carmax rather than sell on craigslist, I found the car was really clean, had 86k on it, and was a limited (leather seats, cold weather package, sunroof). I fell hard in love and had to have it. It ended up at 12.5k out the door. After driving it a little more and sniffing around I found the following mods:
- STI top mount intercooler
- Aftermarket wastegate actuator (yikes)
- Invidia N1 catback exhasut
- Stage 1 Exedy clutch (sketch)
- And a ton of areas where I could see other parts had been removed (coilovers, strut bars, etc)
On top of that, the car felt slow and I after I began logging, I found it wasn't reaching target boost. Obviously this was the aftermarket wastegate actuator, so I switched back to stock and it performed normally. I did a timing belt job around 90k and installed a sound system because the stock setup sucked. This was my baseline and what I would call revision NC (no change).
Coming from a background in Megasquirt (DIY standalone ecu that is pretty involved to build and tune) I wasn't intimidated with the whole open source/ecuflash setup. I got romraider setup and a friend hooked me up with a Tactrix cable. Cool, so far no $ spent. I began more logging and couldn't help tweaking it a bit. I'd call it a stage one tune as it raised boost slightly and threw a little more timing at it. Ran fine, only slightly more power but I was hooked. Almost immediately I bought a used downpipe off craigslist and then added more boost. Ran into some knocking issues at around 17 psi so I dialed it back a fair amount. I was driving the car up the mountains every weekend to ride my mountain bike and got in the habit of leaving around 11pm friday night so the twisties were clear by the time I got there. Lets just say the car had a fair amount of "use' during that time but performed great.
At the time I also had my 250 whp turbo miata which satisfied my mod bug and helped me stop tweaking the reliable daily. Sadly that didn't last long. After I sold the miata, shinanigans ensued. Ill keep it brief;
- VF48 Sti turbo
- 2004 Forged Sti BBS
- Crawford AOS
- 1 step colder plugs
- Many reflashes and testing
- Clutch fork snapped one day, pulled tranny and replaced.
- Then the pedal assy under the dash cracked and failed, bought used off ebay and welded in support bars.
- Built a custom trunk storage box to house JL 10W7 and other tools
- New axles, intake couplers, ac orings/recharge, brakes, turbo inlet, injector orings, coolant, trans fluid, axle seals, and much more.
RUH ROH
At around 148,000 long hard miles, I noticed symptoms of oil tube pickup failure. Mainly, the car made hollow metallic sounds at very light load at 2-3k rpm and the oil press light took about 3 seconds to turn off after cold start. After tearing the old oil starved engine down, I thankfully found no damage, likely because I caught it early. The valves were shrouded in carbon buildup and I'm guessing that was part of the cause of some of the issues I had with that engine. Towards the end I had cylinder 1&3 misfires pretty consistently and a lot of false knock, probably due to lack of oil causing excess engine noise. I'd always been suspect of the old engine and was collecting parts for awhile, first to do a 6 speed swap, then a low mileage engine showed up on craigslist and mysteriously ended up in my garage...
- Replaced engine with 90k EJ255 from 07 wrx
- Swapped in 6 Speed from 2005 STI w/30k miles
- Auto DS 90k
- 2007 auto impreza 3.9 r160 90k
- Act extreme pp/street disk/chromoly flywheel/act TOB
- Tomei headers/up pipe
- Ported/tgv delete intake manifold
- Intake plenum spacers
- Air pump delete
The fuel mileage dropped from 23-24 mpg to 19-20 mpg and it makes waaay more torque and can spool very fast. Tranny is much more rear biased and can spin inside rear tire easily. I miss the 3.7 gears for the freeway but love the short gearing for spirited drives. I'd do the swap again in a heartbeat. Not sure what caused the large mileage drop, logs show new engine is running much better than old.
Can't Leave Well Enough Alone
Now after 168,000 miles the scoob and I have gotten pretty close. My commute is about 60 miles per day into downtown LA so we're talking stop-n-go traffic, crazy pot holes, railroad track jumps... the whole shabang. This car does not live easy. I'm at a fork in the road now because I measured about a quart of oil burned every 1000 miles and I can tell the engine isn't 100%. It talks to me on these long commutes and it tells me it's tired. It makes me a deal; if I don't check it's compression then it won't blowup during one of my revlimiter freeway entrances... I trust the mechanical hardware but I don't trust the computer. I don't trust that I have all the rom data locations correctly labeled or reverse engineered. I think this is why so many people blow these cars up... they trust other peoples reverse engineering without understanding that what we think we are changing is not always what is changed in a factory ECU and the FACT that when editing a tune, we don't have all the pieces to the puzzle. I'm looking at options for economical ways of installing a standalone ECU into the car but there are some issues:
- Drive by wire throttle
- OBD2/Smog
- I'd lose the factory knock feedback (really safe)
- Cost at least $1000 if I use MS3Pro and make my own boomslang harness
So if I do this, it'd be a stand-along install of a megasquirt. I like the MS3Pro (~$900) or MS3 kit+MS3x exapnsion combo (~$700) because of the ability to run sequential fuel and spark. That's the only way to run EFI on a street car IMO.
The other option is to swap in a V8... and keep the STI trans/driveline. It sounds like a lot of effort and would cost way more. But it would be different and much more reliable for the power levels I'm after.
After some measurements, things would be very tight in the engine bay. I'm considering using the Gm 5.3L LS4 engine. This was used in front wheel drive vehicles and is modified to fit in the location. The main differences are:
- Flipped intake manifold (TB facing rear of engine)
- Remote water pump/shortened accessories
- Shortened Crank Nose & Flywheel faces
Resulting in a crank pulley to flywheel mounting surface of crank length of approximately 24.5". Compared to the EJ255 in my car at 17". The distance from trans mounting face to radiator without fans is 22"....So not gonna just drop in, plus the engine/trans adapter width, equals no go. I need to verify the measurement of the engine but here are some other common engines and their lengths:
- LS1: 27.5"
- 1UZFE: 24.5"
- Audi ABZ: 19.3" (Older tech and not very popular)
- Audi RS4 V8: 21.5" (Pricey and not "easy" to standalone, be easier to build the EJ and run more boost)
- Porsche 4.5 Twin Turbo ?
- GTR 3.8 ?
- 370 3.7 ?
My other [cheaper/easier/lamer] option is to build the original engine I pulled due to the oil pickup tube crack. It ran fine and the bores look great.
The Reality of Subaru's
If you're a true Subaru enthusiast then you know the only way forward is more mods. The soob and I are coming up on 190,000 miles and I haven't made too many changes since the last update. Just some minor tweaks:
- Garrett GT3076R with ATP hotside and 3" inlet
- Injector Dynamics 1050X
- 3" MAF housing
- 3" Borla Hush Exhaust
- 2004 Sti LSD Rear Diff and Driveshaft
- Insane Shafts 500hp Sti rear axles
- 2004 Sti rear knuckles (5x100 to keep my wheels)
- Truhart lateral links and trailing arms (rubber bushings)
- Sti Gravel Spec Rotors (so I could keep my 4pot/2pot brakes)
- Tokico Dspec Struts
- Group N top hats
Which explains why my ACT extreme pressure plate can no longer stop the street disk from slipping. But the setup is much more to my liking and too fun to launch... another reason the clutch is dunzo but that what all this is for!!! The motor is still burning the same amount of oil, and part of the reason I did the GT3076R was to make sure it wasn't the VF48 losing oil...which it wasn't. The cars around 15psi of boost and happily runs into the rev limiter at 7K. I treat it kind of like a rotary motor (did you know that you're SUPPOSED to run rotaries up to redline fairly often to clear out the carbon?) and it has been living without issue. I'll admit that I spent quite a bit of time characterizing the 3" MAF to make sure my AFR's were accurate. Also the ID1050X's required some magical keystrokes to fix the Injector Min Pulsewidth which isn't defined in A8DH202X (06 WRX Rom file). This caused the car to run way rich at idle so I had to reverse engineer this parameters location and set it correctly. After I finagled all that and a bag a chips it runs smoother than it did stock!
I still have a taste for that 5.3L, hell I think about it almost every drive but the hurdles to fit that sucker... I bet the driveline could handle it. I bet I could find an Sti clutch disk that is the right thickness and diameter for the LS pressure plate. Then I'd just have to fab the Sti trans to LS4 adapter plate. Can't forget about the pull-style clutch fork either... I wonder if a Sti push-style conversion kit exists? or LS pull style PP? Hmmmm...time for more research.
Built Motor Thyme
Well, at 193,000 I finally caved and built a mean bastard of an engine for it:
- New factory Subaru block
- Manley Forged I beam turbo tuff rods
- King Rod and Main bearings
- JE Pro Series pistons
- Stock valves (sodium filled)
- Brain Crower Valve Springs
- GSC Stage 2 Cams
- Factory head gasket
- Arp head studs
You know how slopes tend to be slippery? I also installed:
- "Stage 3" Segmented disc Comp Clutch which is my favorite clutch I've driven to date in any car
- Aluminum front control arms from an STi (more caster)
- RCE yellow springs
- Hotchkis 1" hollow swaybars
I'd be a liar if I didn't include the part where I initially built the engine using CP pistons and they slapped so bad I thought it was rod knock. So within 500 miles of the first build I tore it all back apart and rebuilt it using the MUCH quieter JE's. Turns out pin offset is required on these flat engines.
Of course, this setup can handle some power... so I built a custom software patch which uses a flex fuel sensor wired to the rear O2 sensor to provide ethanol content. The patch contains 3 drive modes which each interpolate separately between 5% ethanol and 90% ethanol. Each drive mode has different boost, fuel and timing maps and the patch also contains launch control, flat foot shifting, flashes the CEL if a knock event is detected and loads of other functionality. I can't take credit for the patch logic, that was created by gentlemen over at Romraider. I can take credit for being one of a very people who have implemented the logic into a street driven 2006 WRX however, and boy is it great!
First Track Day in the WRX
It's my anniversary! No not with the Subaru, with my fiancé and she wanted to do a track day with me in celebration of it. (She's pretty rad right?!)
We booked auto club speedway in the Roval configuration. Now, if you're not aware, this is the pants pooping config. Of course I showed up with new tires, new brake pads, fresh fluid, fresh alignment, fresh oil and I added in 4 point Schroth harnesses to keep us glued to the seats.
