EA81T non water cooled turbo to water cooled

[K9WAGON]

My non water cooled turbo is more then likely kaput and I'm sure I will have to change it.

 

Now the question is, what would be the best way to route the water lines?

 

I have the OEM Subaru retro fit kit (hose fitting for the intake manifold and the CTS+wire) but I do not have one for the head, and I would rather dump the hot turbo water somewhere better. Maybe the heater core?

 

 

And a followup, would putting an ea82 turbo on be a good upgrade? if not I can put a water cooled ea81 turbo on. (I'm aware the downpipe is slightly different but that's not a problem)

[Crazyeights]

I have all of these same questions/problems about an EA81T I am slowly rebuilding. Any pictures or progress you care to share in this tread would be greatly appreciated.

 

Thanks,

Jeff

[naru]

There is more than one way to route the water lines.

I added a T to the upper coolant line going to the water valve for one.

Other one connects to the drain on the front bottom of the RH head.Cable clamps on the valve cover bolts guide the hose.I improvised a sheet metal heat shield for the line near the turbo.I used thick style reinforced coolant hose.Plan to swap to silicone and replace the rock hard oil drain next time the turbo comes off.

 

Surpisingly,high temp silicone seems to work just as well as the slightly pricey gaskets if carefuly applied.

 

Been working for years now.

 

I may have an extra fitting and banjo bolt if you are unable to locate one.

 

I always thought the water cooled EA-81T turbos supplied during the recall were identical to the 1985 EA-82T VF2 turbos.

Are you saying that you have a watercooled VF1 with the smaller wheels?

 

Regardless,an EA-82 turbo works well on an EA-81T.

I suppose it could be considered an upgrade

Slightly slower to spool,better flow once it gets going.

I would not change the original unless it is fubared.

 

My advice for a happy life w/the EA-81T:

Stock boost

Synthetic oil

Full 2 minute warm up before driving,take it easy until warm

Don`t shut down TOO hot(like right after a full throttle run)

Buy the best gas you can(94 octane for me)You don`t want the knock sensor pulling timing back at all.

[Quidam]

If you tap into the "in" heater core hose you'll be sending the hot turbo coolant, via the "out" hose to the water pump, where it gets sent right back through the block.

 

Sent to the intake manifold/thermostat housing area/upper radiator hose, it gets routed through the radiator.

 

hth and makes sense.

 

Doug

[naru]

If you tap into the "in" heater core hose you'll be sending the hot turbo coolant, via the "out" hose to the water pump, where it gets sent right back through the block.

 

Sent to the intake manifold/thermostat housing area/upper radiator hose, it gets routed through the radiator.

 

hth and makes sense.

 

Doug

 

That is incorrect.

There is no connection to the out hose.

Turbo water returns thru the RH head to the thermostat housing radiator/bypass.

 

It did occur to me that flow may be reversed.I doubt it.

It would be interesting to verify the direction of coolant flow w/some clear hose or such.Thermostat opened/closed.heater valve open/closed.

I can`t be bothered.It works.

Edited April 7, 2012 by naru
furthur thoughts

[skishop69]

Returning it to the thermostat housing will not work. Flow rate in the system will cause the coolant to either stagnate or flow backwards. NAPA carries 'T's that allow you to splice into a rad hose with a heater hose (or smaller) port. Do this after the t-stat and the coolant goes to the rad. What I'm doing is adding a small fan cooled motorcycle radiator from Evil Bay with an electric pump and making a stand alone cooling system for the turbo and intercooler. Of course, I have a few of the stock EA82t AWIC's.

[naru]

Returning it to the thermostat housing will not work. Flow rate in the system will cause the coolant to either stagnate or flow backwards. NAPA carries 'T's that allow you to splice into a rad hose with a heater hose (or smaller) port. Do this after the t-stat and the coolant goes to the rad. What I'm doing is adding a small fan cooled motorcycle radiator from Evil Bay with an electric pump and making a stand alone cooling system for the turbo and intercooler. Of course, I have a few of the stock EA82t AWIC's.

 

That sounds less than ideal.

Your motor will take longer than normal to warm up.

Same thing as having the thermostat stuck open all the time.

 

It DOES work.

It is my understanding that the factory kit returns coolant to the housing where the temp sender resides as described by the OP.

[carfreak85]

EA81Ts!!! I just took a peek at my '84 w/ TSB kit and coolant is pulled from below the thermostat housing, over the top of the engine to the turbo.

 

The return line drops out below the turbo's bearing housing, wraps around the valve cover and dumps into the leading edge of the bottom of the passenger's side cylinder head.

 

 

What turbo you want depends on what you are willing to do for the sake of durability and what your budget will allow. I ended up having a custom stainless header built because my factory one cracked badly on the return leg of a road trip to Whistler, B.C. This is the result:

 

 

A link to more pictures can be found in my profile.

 

I could have gone with a larger turbo, given the opportunity to change the turbine inlet flange. I may in the future, but I just got my WRX back on the road and funds need to go elsewhere before I can come back to the wagon.

 

I would say that you probably want a water-cooled turbo for increased longevity, but if you are fastidious about warm-up and cool-down procedures and oil changes/maintenece, an oil-cooled turbo is all you need, but you have less of a magin of error.

[K9WAGON]

There is more than one way to route the water lines.

I added a T to the upper coolant line going to the water valve for one.

Other one connects to the drain on the front bottom of the RH head.

can you clarify?

 

I always thought the water cooled EA-81T turbos supplied during the recall were identical to the 1985 EA-82T VF2 turbos.

Are you saying that you have a watercooled VF1 with the smaller wheels?

I think so? I'm only basing this off a turbo brat's turbo I had worked on. The ea81's downpipe is slightly different and the ea82 turbo looked a tad bigger.. I'm guessing the other turbo I have would be the same.

 

NAPA carries 'T's that allow you to splice into a rad hose with a heater hose (or smaller) port. Do this after the t-stat and the coolant goes to the rad.

 

That sounds less than ideal.

Your motor will take longer than normal to warm up.

Same thing as having the thermostat stuck open all the time.

 

It DOES work.

It is my understanding that the factory kit returns coolant to the housing where the temp sender resides as described by the OP.

The turbo seems to get fed water from under the t-stat, where the CTS goes. Returning it to the other side of the t-stat would work untill the t-stast opened up, then who knows what would happen.

 

 

EA81Ts!!! I just took a peek at my '84 w/ TSB kit and coolant is pulled from below the thermostat housing, over the top of the engine to the turbo.

 

The return line drops out below the turbo's bearing housing, wraps around the valve cover and dumps into the leading edge of the bottom of the passenger's side cylinder head.

Yeah! I would rather return that somewhere elce if it's an option.

 

What turbo you want depends on what you are willing to do for the sake of durability and what your budget will allow. I ended up having a custom stainless header built because my factory one cracked badly on the return leg of a road trip to Whistler, B.C. This is the result:

 

 

I would say that you probably want a water-cooled turbo for increased longevity, but if you are fastidious about warm-up and cool-down procedures and oil changes/maintenece, an oil-cooled turbo is all you need, but you have less of a magin of error.

 

nice headers man!

 

Unfortunately, spinning the turbo by hand it gets a bit of resistance before it makes a full revolution. Think its savable? I'm almost certain the PO shut it off when it was super hot.

 

So lets say I feed the turbo from under the t-stat, from the turbo goes into the heater core, and the heater core feed line goes into the head.

and the heater returns to the stock location.

 

or can I simplify it even further by adding a T somewhere without having to ever feed hot coolant to the head?

 

Or should I give up on the whole "Improving Subaru's design" and route it all stock?

 

 

 

Thanks for all the responses!

[Quidam]

That is incorrect.

There is no connection to the out hose.

Turbo water returns thru the RH head to the thermostat housing radiator/bypass.

 

It did occur to me that flow may be reversed.I doubt it.

It would be interesting to verify the direction of coolant flow w/some clear hose or such.Thermostat opened/closed.heater valve open/closed.

I can`t be bothered.It works.

 

Hey Naru,

 

Here's the fsm chart for an EA 82. Coolant flows from the right head to the turbo.

[K9WAGON]

well, good news is, when i went to change my turbo. a whole bunch of mouse nest was caught in the turbo, I cleaned it out and IT WORKS!!! :banana:

 

 

spools great.

[skishop69]

"That sounds less than ideal.

Your motor will take longer than normal to warm up.

Same thing as having the thermostat stuck open all the time."

 

Actually it works just fine (as I've dome it before) and flow through the turbo is negligeable and barely affects warm up time. That coolant flow diagram gives great info. You can definitely figure out the best route with that.