Could Outback H-6 Powetrain fit in 03 N/A Baja?

[davecoon13]

I have a 2003 Subaru Baja (Naturally Aspirated), with 4EAT Automatic Transmission. Now that the Baja is no longer produced (It really is the perfect car for me!), I am gonna run that car into the ground. I am curious though, if and when the time comes and the motor finally dies, would an Outback H-6 Engine fit under the hood? Would it have to be coupled to a new transmission, or would it bolt right in and couple to the existing transmission?

At first glance, the front end of the Baja looks the same as the second generation outbacks (from Model Years 2000-2004 or so). Would it fit?

[Hawk296]

yes it will fit. It takes a lot of wiring though

[davecoon13]

yes it will fit. It takes a lot of wiring though

Will it couple to the 4 speed automatic tranny or must I get a tranny specifically for the H-6?

Could a mechanic do the wiring or must it go to the Subie dealer? What kinda wiring? The ususal sensors and stuff? Alternator?

[speedymatt]

the engine should be able to physically bolt to the auto trans you have without a problem because i think the h6 uses the 4eat as well. the only thing i'm not sure on is the VDC center diff and how that plays into the wiring.

as far as the wiring issue and why its a pain is that your either trying to trick a four cylinder ecu into controling the firing of a six or trying to wire a six cylinder ecu into a four and have it control all the other sub-systems. i doubt a general mechanic would be able to handle the wiring unless the shop does swaps regularly, and i doubt a subaru dealership would even touch the project.

i would think to make the swap painless you would need the engine, drivetrain, ecu and wiring harness of a wrecked donor h6 and then the wiring services of a swap shop. your almost better off getting a turbo baja or 04-05 sti drivetrain and use a stand alone engine management, atleast that way your in the ballpark of having the wiring done. that is my plan for the baja when the time comes, 04-05 sti engine, stand alone em, 6spd with the dccd. oh and the license plate SPR BRAT (read super brat).

[Hawk296]

ALL Subaru engines will bolt to all subaru transmissions. So an H6 will bolt to the same 4eat as a 4 cyl or a turbo 4.

Since you have a 03, you do not have VTD. The engine mounting points and such are all the same. The engine will physically bolt right in. The Exhaust needs to be changed (different headers etc) ECU compatibility will be the main issue. you will for sure need a new ECU and engine harness to go to the new engine. Your best bet is to get all of that from a 2003 since its closest to your model year. From there you can probably do a combination of splicing and re-pinning all the needed wires in the car, or since the baja is so closely based on the outback you might be able to swap out entire sections of the harness if you can find a donor car. It very well may be that this will be quite more involved than a turbo or STI swap in your current car.

If I have time this weekend maybe I can look at some wiring diagrams and ECU pinouts and see how different they are.

[speedymatt]

^^^ i wasn't sure if all the h6's came with the vtd diff, so my concern was for the situation of using the h6 ecu and it looking for the vtd diff and not finding it in the baja and that adding to the wiring problems.

[davecoon13]

If I have time this weekend maybe I can look at some wiring diagrams and ECU pinouts and see how different they are.

Don't bother just on my account. I just wanted to get a sense of how complicated this swap would be. My car still works fine, just hit 47,000 miles (almost paid off, in 2 more payments it will be paid off!)

It seems pretty involved. Hopefully I won't have to consider this again until after several more years of service.