I've been registered here for a while, but as a reflection of my progress on my project , I haven't actually done anything on the site.
I have a '97 Subaru Legacy 2.5GT, which has done daily driver / auto-cross / track day duty for me since I bought it in 2000.
The late '90s 2.5GTs were non-turbo, with the DOHC 2.5L EJ25D rated at 165/162 hp/tq. Over the years, I did a variety of modifications to the original EJ25D - ported heads, reground cams, header, etc - that resulted in a significant bump in power, to something around what a stock 2.0L WRX puts down. Yes, I realize many would think that was a poor ROI compared to just doing a turbo swap, but I've never had any desire to go the turbo route (note the license plate in the above pic).
However, more power is more better, so at some point I started thinking about swapping in the EZ30 6-cylinder from the Outback. Initially I was planning to use the 2nd generation EZ30, commonly called the EZ30R, which was offered starting in '05 in the US. Rated @ ~245bhp, DBW throttle body, variable intake cam timing and lift, blah blah blah. I picked up a very lightly used EZ30R years ago and was intending to swap that in the car. Since the 30R uses a CAN-bus type ECU with an Immobilizer, it's very challenging to use the factory ECU (I've only ever seen discussion of 1 person successfully accomplishing that), so I picked up a Vipec V88 to run the engine.
4 years ago, I was still running an EJ25D, planning to do the 6-cylinder swap "some day". Then I managed to hydro-lock the EJ25D , and suddenly it seemed like it was time to do the H6 swap. Unfortunately, I had run into some issues getting the 30R cylinder heads worked on by a shop, so the first H6 I had purchased wasn't ready to go. I came across a great deal on a used 1st generation EZ30, commonly called the EZ30D, so I bought that and rebuilt it. The 30D doesn't have the fancy variable cams, is drive by cable, and is only rated 212hp.
So, I proceeded with the swap, and mechanically pretty much got things done as of 2-1/2 years ago:
I had spoken with a Vipec dealer / tuner here in the US about installing & tuning the ECU for me - he was only a few hours away, so it would've been quite convenient. Unfortunately, by the time I finished all of the mechanical stuff, and then had to pack all of my stuff and relocate due to a change in duty station, he was no longer in the Vipec business. Well... damn. Thus began the long, stagnant period, during which I ignored the thing and hoped that the wiring harnesses would magically merge on their own. That has still not happened , so I might actually have to do it myself!
I've gone through the Subaru engine harness wiring diagram and created a nice Excel spreadsheet of everything. I had sourced a complete main dash harness from an '01 Outback; I've culled that down to just the connectors that plug into the engine harness, each with long pigtails for merging purposes.
Now I just need to figure out matching up the EZ30D pinouts to the V88 pinouts, some of which is pretty obvious, but other stuff I need to do some homework. And then I need to actually merge the harnesses, something I've never undertaken before. At my current pace, I'm reasonably certain I will have the project completed at some point this century, maybe even this decade.