TT Legacy Project

[Hotshot]

Alright, I went and bought myself a mostly completed EJ20R twin turbo swapped legacy. I do realize that this might not quite be the right gen of legacy for the forum, but everyone here seems to be more knowledgeable about how to get a turbo engine running right.


on the truck on the way home


Profile shot


Interior


Awesome folding rear seats. They go completely flat.


And the reason this is getting posted here.

As far as I can tell, the wiring for the ECU is already mostly completed, but I need to find the connector from the rear harness, and sit down with wiring diagrams and a soldering iron. I still need to find a set of fans for the radiator that I have for it and get that put in, I need a fuel pump to keep up with the engine.

Right now I'm in the process of trying to figure out where several loose hoses are supposed to go, particularly all the vacuum hoses that control the operation of the two turbos.

First question: What do subaru turbos use as far as cooling? As far as I can tell, it has oil lines running from the block to each turbo I would assume for lubrication, while there are other lines running to the turbos from a small reservoir on the top left side of the engine. I assume that that would be standard coolant to cool the turbos? There are two fittings on the top of the reservoir, one is a return and the other looks like a pickup. I'm not 100% sure where they go. My best guess so far is that they hook up to the turbo radiator that I have for it.

Is there something similar to a hayes manual for JDM stuff?

This morning I spent most of my time figuring out how all the different components of the twin turbo setup are hooked up, and how all the vacuum lines control them. I was getting a little nervous about finding out how they were supposed to meet at the solenoid to control them, but thank god they numbered all of the outputs, and all the hoses, and I found a diagram on some English web site that says where they are all supposed to go.

I also tried hooking up the downpipe to the passenger-side turbo, and found the crossmember that needs to be modified for it to fit. Also emptied the gas tank of all the fuel left in it, it smelled pretty old, and there was a good bit of rust inside the tank that seemed to wipe out with some rags and some elbow grease. Unfortunately, I have to head back to the real world so it might be a week or two before I get a chance to do much else. I am going to get the fuel pump in it next time I have a chance, hook it up to a battery, give it some gas, and hopefully it may turn over, and if I get really lucky it might run.

Did have another interesting incident today. When I was siphoning the contents of the gas tank into to a 5 gallon bucket, another guy working in the shop was grinding on the headers he was making for his suzuki. Although he was about 15 feet away, a spark from the grinder managed to land right into the bucket of fuel and set it on fire. That was a little bit of excitement.

I'm know that I am in a bit over my head with this, as I have never owned a turbo before and I now have two of them, on the same engine nonetheless, but I figure it will be a learning experience. I'll keep this thread updated with whats going on with it.

[vrg3]

Over your head? Wow, dude, I don't mean to be condescending, but what were you thinking playing with fuel near someone using a grinder?! I'm glad you're still with us. Be careful with your new project! Or at least leave it to me in your will.

But anyway... to address your questions... I'll tell you what I know from the single-turbo models, and maybe we can extrapolate to figure some stuff out.

Subaru turbos are water and oil cooled. The water is part of the engine's cooling system. Water is supplied to the turbo through that reservoir you're talking about. The reservoir is the highest point in the cooling system, and holds the radiator cap -- the radiator on this model has no cap at all. The little fitting right by the radiator cap goes to the overflow reservoir. The other little fitting goes to a nipple on the radiator.

The other side of the turbo's water jacket is plumbed to -- on our models -- the cylinder head. So when the engine's on coolant goes from the tank to the turbo to the head.

If the turbo is hot when the engine shuts off, it'll boil the coolant in the water jacket. The vaporized coolant then moves to the reservoir, and the partial vacuum then draws fresh coolant in from the cylinder head. That helps the turbo cool off without cooking its bearings.

I don't know of any third-party manuals for JDM models.

I'm glad you figured out the boost control vacuum plumbing... that is probably the hardest thing to figure out without a clear guide.

It sounds like whoever did the swap may not have changed crossmembers. The single-turbo engine crossmember has a reinforced notch in it to clear the downpipe. I believe the twin-turbo crossmember has reinforced notches in it for both downpipes. I would recommend getting the right crossmember. But, if you're modifying yours instead, just make sure you don't create a weak spot.

You might find more expertise at the RS Liberty Club: http://www.rslibertyclub.org/ . People there see twin turbo models much more than we do.

You're in for a fun project! I'm envious. Keep us posted!

[Hotshot]

In my defense, he wasn't using the grinder when I started, but yeah I should have recognized the potential hazard before the situation turned into something more dangerous.

According to your description, the cooling system for the turbos seems to work the same was as on the single turbo engines. I did notice the lack of a filler cap on the radiator, which did alarm me a bit, and the radiator also has two brass fittings on either side which I am pretty sure are for the AT model engines. That threw me off a bit also, but I think I'm back on track now.

As far as the downpipes for the TT, the one on the driver's side of the car seems to fit fine, and is currently on the car. Being a college student, I think I will just try and modify the existing crossmember, and possibly add a little of my own reinforcing to it if it is necessary.

There is no exhaust on it past the Y pipe at the moment, so I can't wait to hear the engine run like that. I am planning on just having an exhaust fabricated for it instead of trying to find a stock exhaust or paying ridiculous sums of money for an aftermarket catback. I was thinking 2.5" with a high flow cat in case I ever decide to do any modding.

Thanks

[vrg3]

Again, I'll repeat the disclaimer that I only know single-turbo engines. That said...

The fittings on the side are for the ATF cooler, like you guessed. Just cap 'em off with 3/8" caps.

The fitting that's supposed to connect to the reservoir should be on the upper right (from the driver's seat) corner of the radiator. It should be 7.5mm or about 5/16".

If the driver side one fits right, then my guess is that they installed a single turbo crossmember. The turbo on a single-turbo model is on the driver's side (on an RHD model).

[Hotshot]

Its all there just like you described it. Cooling system should be a breeze to hook up once I get some mounts made to keep the radiator in place. I didn't feel like trying to have one shipped from overseas, so I am retrofitting a radiator from a '93 SS.

I need to get it up on a lift so I can really see whats going on down there, but I believe that the previous owner said that he fabricated a crossmember for it. Is it possible that there is a second crossmember there that the passenger side downpipe is interfering with?

[vrg3]

I don't know. I don't know what the exhaust plumbing looks like, and it's hard for me to visualize right now, but maybe it's interfering with the transmission crossmember?

[Hotshot]

I do think that was the one. I assume that it will be alright if I take a notch out of it for the downpipe to fit? It doesn't need to have much removed. Or do you think it will be necessary to weld in some reinforcement?

[smh0101]

That thing is gonna be sweet!

[vrg3]

I can't say without seeing it. But in general, you don't want to just remove material from structurally important pieces without somehow reinforcing the modified area. And the transmission crossmember is a structurally important piece. Right?

[Hotshot]

Yeah, I suppose you are right. That is going to have to be something I look into a bit before I start hacking away.

[BXSS]

Any update on this?

I think I saw twin turbo front x-members & exhausts on ebay cheap.

[Arctic Assassian]

Can you post up some pictures of the exhaust where it interferes?

BTW I really want that brake booster. It's hella thin.

[Hotshot]

Finally decided that modding the downpipe was a whole lot easier than screwing around with the crossmember. I'll have a shop modify it for me when I need to put an exhaust under the car.

Speaking of, considering a minimalist budget and this being a daily driver, what would you recommend for an exhaust? I was planning on going with 2.5 inch back from the downpipes with a high flow cat and an OBX dual-tip muffler.


Ran into a another bit of a problem. Power Steering lines this time.

The metal lines to the steering rack on the ones I received to match the engine are routed completely differently than the ones that originally came with the car.

So I have a few options, one or two of which might be a bad idea so I am running them by everyone here.

1. bend the lines on the new hose to match the steering rack
2. use a fitting to put together the bottom half of the line from the car and the top half for the engine. (boom?)
3. Make a SS line instead. ($)
4. Power steering is for wimps.

I really haven't had nearly as much time to work on this as I would have liked, being at school and all, so it will be after school lets out in the middle of may when I can really start working on it.

I'll try to remember to get pics of the exhaust next time I'm at home.