EJ25 DOHC Outback Wastegate Pressure Turbo

[davidtocker]

Hi People.

I have a 1996 Outback 2.5 Dohc Legacy (JDM, OBD 1) that I picked up for $800NZD (about $400 USD) it is really tidy but had a blown head gasket (as they do).
I also just happen to have a 1991 Legacy GT (JDM, ej20 dohc) that is totally unwarrantable but also happens to have a mint motor and turbo (VF11).
It can go around in circles in the paddock all day on boost but im quite willing to sacrifice it to build a little more power into the outback.
After reading the posts on the forum for about the last two years and looking at other peoples builds I dont think it is totally unconceivable that I could transplant the turbo, water to air intercooler and other bits of plumbing off the legacy and try to give it that little tiny bit of forced motivation.
The interesting part about the Outback I have is that it appers to already have a bit of the turbo car influence upon it (for example it has a notched x-member and a downpipe type exhaust setup?!?)

My real concerns are:
Oil feed for the turbo
Being able to prevent the turbo from producing more than about 4psi.
Timing
Fuel

I figure with this little amount of boost I can probably get away with a lot, RRFPR seems like a good idea but Im not even sure it is necessary.

I know it may not even seem worth the effort, but you know - i already have most of the bits as far as I can tell (except the oil feed)

So my questions are:
Where would be the best place to get a feed for the turbo? (keeping in mind I have the whole turbo car)
Will timing be an issue with 4psi?
Will I need to worry about the injectors/fuel pump?

Obviously if i wanted loads of power I could just swap the motor and loom from the turbo legacy, but really, loom swaps are just a massive headache and all I really want to do is add a little to the top end and perhaps a bit of torque for towing. The fact that I would have acutally got a turbo running in the thing will be the pay off for me (im a tinkerer)

My thinking is that as long as I loose no air (pumb back BOV) and run very little boost then I probably wont have to worry much about throwing off the MAF and ECU.
The turbo car has all the original Subaru pipe work including the plastic baffle that stops the maf getting confused by the air rush from the plumb back BOV.
Obviously I am rebuilding the 25 motor, new headgaskets, head bolts, water pump etc etc.

Any assistance would be greatly appreciated, between you all you seem to know about all you need to know about these cars

If I can get it all to run okay and not explode within a few thousand kms then I will probably look to moving to a link or emanage but at the moment it seems like a lot to spend when it may not be completly necessary.

[davidtocker]

Have looked further, looks like the oil feed is not a big deal, just have to tap the head or take some oil from the oil pressure sender.
Not really sure about the oil pressure sender although, sounds easier but then im not sure if i will get enought flow?
I have the sump with the oil return.

[davidtocker]

Have had another look at the cars - although the uppipe and down pipe are there, they are totally different from each other - apparenty the turbo does make a difference.
The good news is that the uppipe and the downpipe off the turbo car look like they will bolt up to the factory 2.5 headers and exhaust. Looks like two sensors on the turbo down pipe as opposed to one on the n/a.

[davidtocker]

Does anyone know if the intake manifold off the turbo will fit the N/A? Im thinking there may be clearance issues with the compressor outlet, but it has a 90 degree bend on it so I think it may clear - but then will the intercooler mount to the N/A intake manifold???

[davidtocker]

Sorry if I am spamming the forum - Im in New Zealand so we are 12 hours ahead of the rest of the world- ive just taken some photos for clarity but my son seems to have placed my samsung cable somewhere and my st1000 camera doesnt seem to want to pair with my laptop via bluetooth, japanese engineering at its best... Why get a camera with bluetooth, GPS and wireless if you cant just copy the photos without teh cable????? can upload to facebook from the screen tho...

Just had my new parts ordered, should turn up in the next couple of days so the ej25 rebuild is happening.

[wtdash]

Hi,
Welcome aboard....sounds like a fun project.

1st - are you sure the '96 is an OBD1? They are OBDII in US. If it IS OBD1, the wiring and ECUs may not be all that different from the '91.

The intakes should swap. From what I've read on here all the Phase 1 (pre-'99) DOHC are the same.

Here's some info from 'awdimprezal' who Turbo'd an EJ22:

My entire setup consists of these items.

STOCK internal 1996 ej22, w/ single port heads.
Legacy turbo injectors.
Weapon R adjustable fuel pressure regulator
STI fuel pump
FXT top mount
Front 02 sensor moved closer to heads (about a foot closer then it is in stock form)
1997 legacy LSi (yes DOHC!) ecu plugs right in, throws an immediate code for fuel temp sensor
Ebay t04E turbo
borla single port header
custom up pipe
custom down pipe
TXS BOV.

For oil feed, I run a T fitting off of my oil pressure switch and a braided line to the turbo (with a resctrictor I fabbed up out of a "pill" for a wrx boost line), for return I run it back into the pan (tapped pan). As for the ecu, when I was n/a I wanted a higher rev limit, because I would constantly hit the limiter with this light flywheel, I work at a dealership so I had access to a ratty old legacy and I just swapped ECUs around, just to see. As for the code, yes its for fuel temp, and I have no need or desire to turn it off, as we dont have emissions testing here.

[davidtocker]

Awesome, thanks for that, im going to go search for that thread.

Got all the parts except the head gaskets today (the 1st parts i need dammit!) its OBD 1 for sure, looks like it may be a similar jecs system to what the BC has, same MAF and everything.

Have found a few articles where people have fed off the oil sender so that looks like the one for me, I really dont want to tap the heads jic I have to take it all back off again.

[All_talk]

No need to to tap for oil supply, there should be a plug at the back of the gallery (in the lower right of the photos below).

But you will need a way to get the oil back to the pan. In the photos below i have taped the head in the stock return location and installed a sweep fitting from an aircraft vacuum system.

You will also need a coolant supply, you can tap the head at the factory location (see pics) or you can pick it up somewhere else. Anywhere on the pressure side of the water pump should work.





Gary

[davidtocker]

Well i managed to get the head gaskets for the weekend, have torqued them up and put the heads back together - parts master seem to have confused my tensioner however so I have not been able to put the timing belt back on yet.

Had a good look at the heads while I was doing it - there is one bolt in the head, but it doesnt look like the holes are tapped on the other ones - I took some photos but damned if I can work out how to post pictures on here...

I have replaced all the seals on the shafts, and glooped the plate on the back off the motor, anything else anyone would recommend to seal while I have the engine out? All the Subies i have had have ended up leaking oil somewhere eventually but I would like to prevent it happening too soon [/img]

[davidtocker]

Okay, havent posted for a while, got the car all back together to factory state - goes beautifully now that the head gasket and all that carry on is all done.

In fact it goes so well and is so nice that my partner decided that she liked it more than her saab and claimed it outright "its too good for you to wreck"

All good, went to www.trademe.co.nz and brought another one

This one came with 17" wheels, lowered with rooted rear struts and a bonus hole in the exhaust.
Definitely more ghetto for the boost.

Have replaced the rear struts with the ones from the RS (I can confirm they are a direct swap)
Going to swap the swap bars over as well as they are considerably larger, just what the long pig wants.

I have been thinking about it more and have decided to transplant the entire ej20g over from the RS donor car into the new one, running on the ej25 computer etc.

So far Im thinking that it will work well if I do some adjustment to the AFM signal using the Jaycar fuel adjuster circuit.

http://www.jaycar.co.nz/productView.asp?ID=KC5385

Anyone think Im barking up the wrong tree?