Welcome! My motivation for typing up this monster of an article is so that someone can read through and finish it with a sound knowledge of what to do and what not to do when it comes to turbo-ing an Ej22E. When I prepped for this build, I spent countless hours researching different pages where people talked a little bit about how to do it, but I feel they left out a lot of vital information. This article will hopefully save you hours of research.
Since you are reading this, you probably own a Subaru with the amazing Ej22E. I say amazing because people don’t give it the credit that it is due! My current car is a 1993 Subaru Legacy wagon that has an Ej22E. I slapped a turbo on it, and I am currently run 6 psi of boost. Internals you ask? Stock. Engine management? Stock. Transmission? Stock. Clutch? Okay, so the clutch is not stock. It would just be dumb to use a stock clutch when you are adding 60-80 more horse power (going off of the theory that you get about 9-12 horse power per psi when inter-cooled properly). What people don’t often consider is how fun NA-T (Naturally Aspirated Turbo) builds are to drive. Naturally aspirated motors have high compression ratios so that they can actually make some torque. All the factory turbo cars have low compression ratio’s so they can safely pack in boost. However, they feel like nothing down low until the boost kicks in. That’s why the Ej22E build is so fun.
There are two major versions of this motor: the Ej22T and Ej22E. The Ej22T is the version that came standard from the factory with a turbo, and these have thicker ring lands that can handle more boost before blowing (like everyone has heard of a Subaru doing).
On the left is an Ej22E piston, and on the right is an Ej22T piston. The biggest reason that people enjoy the Ej22T design is its closed deck block. So many people send their STI 257 blocks in to close the deck because the increase in the sleeve size gobbles boost like no other. Subaru no longer closes the decks in their motors due to the costs and the materials it takes to manufacture, but back in the 90’s when they did, these blocks handled the boost you shoved. With the right head, we are talking 50 pounds of boost! Open decks have been known to crack. As I was typing this up in my shop, I realized that sitting in one of the cabinets is an Ej25 open-deck SOHC motor out of a 2006 Legacy that has a cracked cylinder wall. This is the naturally-aspirated version and the wall STILL cracked . Be mindful of this when pushing boost into an open deck block, as well as your piston ring lands blowing and connecting rods pulling themselves apart during the exhaust stroke.
Now at this point you are reading this and saying “I have a Ej22E; it’s open deck with smaller ring lands… So do I need to find a Ej22T and swap it in?” Good question! The Ej22E is still great! 2.2 liters is a great platform to work boost off of and these blocks have been run by lots of people on low boost applications with no problems. Things start to break when you get a little too horny for more boost. I’ll talk more about what this motor can handle later. First, let’s go over what you’re going to need before taking on this project and what I personally did.
- Blow Off Valve
- Oil and Coolant Lines
- Engine Management… or lack thereof 😉
There are two different types of Ej22E’s: Dual and Single Exhaust port. The designs came like this from the factory for two different reasons. The Single Port head has better scavenging of the exhaust flow which creates more torque down low, but also has more restrictions up top. The opposite applies to the Dual Port. Duals flow more, so they can create more power when revved up. The actual power differences between these two designs is minimal, this is just a little insight into the mind of the engineers behind the motor.
Dual ports Single Port
With that being said, my Legacy had Dual Port heads; therefore, I was able to bolt Ej22T headers straight onto it. This will work with WRX headers as well, I just had a friend let me buy his for $20. The disadvantage to Single Port heads is that they take patience and welding skills. To get the Ej22T Dual Port headers on, I just had to remove the water pump from my motor and replace it with one that I stole off of the Ej25 I talked about earlier from the 2006 legacy. This relocated the thermostat housing away from the headers. Any water pump that mounts the housing vertically instead of horizontally will work.
Stock Ej22E water pump and thermostat housing location.
Here on the 2006, it mounts on the side instead of the bottom.
Now you can see that because the thermostat housing sits on the side, it doesn’t rub on the headers.
On my Legacy, I took a 2007 full 3″ STI exhaust and made it longer and sound better!
The next big thing to tackle is your cross member. It was not designed to run an Up-Pipe between it and the block, so there are two options. You can either put in a 90’s WRX cross member, or go the easy and cheap route and cut the sucker down. The process is very simple and self explanatory. You just make your cut right next to the sway bar bracket and go a generous portion out, maybe 6″ wide, so that you can fit the up-pipe and some 1/2″ oil return line.
Regarding the intercooler, what you’ll read is a lot of people started with a 02-04 WRX intercooler, got sick of the fitting issues, and eventually switched to the 06-07. I skipped that frustrating step and went straight to the 06-07 (which happens to be the same as the 06- 08 Forester’s intercooler). Everyone asked me — why didn’t you go front mount? The simple answer is that there is no room in my current bumper, and it would have taken several hours in custom guessing until something worked. Front mount is an option, it just isn’t what I did, so I’m not much help with the fabrication of one.
Basically, it looks like it will work a lot better than the fatter ones on the 02-04. Fitting it is easy, you just get a silicone adapter with two hose clamps and stick it on. This is the easiest part of the build.
Blow Off Valve
When you think turbo’s, you also think blow off valve sounds. They go hand-in-hand. Everyone has their favorite turbo sound, and it is probably compressor surge. This classic “wootootootoo” sound is actually the air forcing its way back through the spinning compressor turbine, chopping the air, and creating that sound. I have read about how people have fitted blow off valves onto these builds, and some people have deleted their cruise control to make it fit. I couldn’t see how to make that work, so I just took the piece of metal that I cut out of my cross member, and hit it with a hammer till it was flat. I then drilled two holes in it and blocked off the hole in the intercooler. Now when I let off the throttle, it makes crazy compressor surge sounds. Some will say this threatens the life of the turbo. Yes, I agree. BUT my buddy ran a TD04 on 15 psi with a block off plate for 15,000 miles before going to a bigger turbo. We know that TD04’s are good for about 100,000-150,000 miles if really well taken care of. He was running twice the boost I’m running right now. So even if it cuts a turbo’s life in half, at least it sounds damn good. Yeah, I know that is all guessing at this point, but this will work for a low boost application and it will turn the heads of anyone walking on the sidewalk. I won’t be using this turbo for that long. My motor will be built, and I’ll be boosting with a VF48 soon, so a block off plate works for me.
Every company and their grandma makes turbos these days. We have all spent hours sitting on Garret Turbo’s page comparing this ball bearing to this journal. When it comes to turbo-ing a Subaru, the WRX guys like to upgrade to STI turbos. The STI guys usually upgrade to either a Cavalli triple ball bearing turbo or a GTX turbo. For us naturally-aspirated guys, any turbo at all is an upgrade. This is where the used turbo market is our friend. When purchasing a used turbo, you always hear the term “shaft play”. Journal bearing turbos have shaft play from the factory; it’s in their design. When inspecting a turbo to figure out if it is an appropriate purchase, grab the compressor turbine wheel. The wheel should have some slight play in its up and down, and the blades should not be able to make contact with the compressor housing itself. Now push and pull back and forth on the wheel. This is where it should have zero play. Next, spin the turbine to feel for resistance on the wheel and listen for any strange sounds. If it meets these criteria, it should boost for a good long time. I purchased my TD04 for $50 from a turbo diesel mechanic. He offered me a generous price for it’s pristine condition due to his excitement to start a Gen One Legacy turbo build. You should be able to get a well-kept turbo for $75-120. Don’t make due with a turbo that isn’t as solid as it should be; it will only cause troubles down the road. Nothing would suck more than ending up with a grenade for a compressor wheel just because you wanted to save $50 on your turbo.
This is where we get to talk about legos! I loved legos as a kid. Now my daily driver literally is a lego. Since we had already taken WRX headers (or Ej22T headers), an Up-Pipe, and a Down-Pipe, we used a Subaru turbo that already has these flanges. The turbo bolts to your exhaust exactly like a lego would. You have several options, but the two I would recommend are either a TD04 or a VF11. The TD04 comes on the WRX from 02-08 or even on some Foresters. The earlier TD04’s don’t have a flange on the end of the compressor housing outlet. This is good because you don’t want the flange since it prevents the outlet from sliding inside your intercooler. A TD04 has a waste gate pressure of 6-8 psi depending on what year. If you were to take a little 5″ piece vacuum hose and connect your compressor housing vacuum port to the vacuum port on you waste gate actuator, it would act as your boost controller and hold you at 6-8 psi.
The VF11 which came off the Ej22T is a little smaller and the waste gate actuator is set to 5 psi. The VF11 has a 90* inlet that faces up. The TD04 was the easiest to use in the build because it was meant to go into the intercooler we had purchased, though the TD04 has a front facing inlet and requires a 90* to mount your intake. The VF11 would take a little persuasion and would make your intercooler sit at a funky angle. I actually ran both in the first week I did this build for reasons I’ll explain in the oiling and coolant section. If you look at the picture in the intercooler section, there are two turbos sitting in front of it. The turbo on the left that is sorta purple is a TD04, and the one on the right is a VF11.
Your turbo is going to need an oil feed line and an oil return line in order to run. The oil feed is really simple to assemble. Underneath your alternator is a little oil pressure switch that activates when your car is low on oil pressure. I know this because I had this light come on before I boosted the Legacy…. That oil switch is a 1/8″ thread that, in order to fix, you need to go the the store and buy a tee with 1/8″ female on all sides. Then, get a male and male adapter on both sides that are 1/8″. Thread that adapter into the tee (and don’t forget Teflon tape). I put the male and male adapter on the bottom of the tee and then it goes into the block where the pressure switch was. Next, thread the switch into the side of the tee facing the front of the car. Then you are going to need a 1/8″ adapter that has a barbed end for 5/16″ hose. Once that barb is in facing the firewall, you are ready to feed oil. Now that that is all set up, you’ll need 4′ of 5/16″ fuel injection fuel line, or a hydraulic oil line/braided oil lines. As you can see in the picture below, you should hose clamp that on and then run the line up to your turbo. I bought a full TD04 oil and coolant kit, and it came with all of the banjo bolts you need. I’ll explain one thing you need to be super careful of in a minute when I talk about the mistakes I personally made when it comes to banjo bolts and oil feed for a turbo.
Running oil return from the turbo is critical. It has to be as unrestricted as it can be. Gravity is your friend and also your enemy. It helps the oil leave the turbo since it is facing down, but it doesn’t go up which means you have to have your return line flow down. This leaves only a few options. I read that some people drilled a hole in the bottom of their valve cover and returned it in there with a 90 degree fitting. I personally drilled a hole in my oil pan and welded a nut on inside it and taped it to NPT (National Pipe Thread which is a tapered thread that seals it’s self as you tighten it). Then I got a 90 degree NPT fitting with a 5/8″ barbed end and threaded it in. Next, I ran a couple of inches of 5/8″ hose followed by another 90 degree fitting that was barbed on both ends. This was then used to turn around the bend in the oil pan to avoid kinking the hose since the hose has to be as unrestricted as possible. Now that it goes 90 degrees around the pan, it can follow the up-pipe through your notch in the cross member to the return fitting on your turbo. It helps if you wrap the up-pipe in exhaust wrap to keep the heat off of the hose. In fact I would recommend having both your up-pipe and down-pipe wrapped and a turbo blanket on. Do your best to prevent heat soak in the engine bay. Just be mindful of all wrap you put on the exhaust. If oil gets spilled on the wrap, you could potentially start a fire. Remember, you drive a Subaru, not a Ferrari. Your car shouldn’t be catching on fire. #458ItaliaBurn
When lubricating any turbo application, keep in mind the following facts. At idle, a turbo needs a minimum of 5 psi of oil pressure and a max of 8. At full load, a minimum of 22 psi and max of 25 psi. Now, since we tee’d off the oil switch (which is going to get full oil pressure) how do you stop full oil pressure going to your turbo? This is where the banjo bolt comes in. When you thread it into the oil feed port of your turbo, it restrics the oil pressure. When I bought the oil and coolant line kit it came with a banjo bolt that had two massive holes in it. That doesn’t cause any restriction whatsoever, so make sure that your bolt has only one pin hole as shown in the one below.
When I was assembling my turbo build, I set the whole thing up for the TD04. After three days, I finally started it up. It sat there and idled while I waited for it to get to operating temperature. Once there, I started to slowly rev it a little while checking everything. Suddenly, the idle changed in a weird way and when I looked under the car, all of the oil was just blowing out my Down Pipe which was the only exhaust piece I had hooked up. I immediately signaled for my buddy to shut the car off. Since the TD04 just blew, I went with the VF11 I had sitting in my closet. The TD04 blew for two different reasons. One, I used the banjo bolt I got from that kit that didn’t restrict oil pressure. Two, I hooked the oil return hose to the turbo then kinked it up above the turbo and back down to the valve cover breather port. I had read that that was what other people had done. The unrestricted oil pressure in the turbo due to the bullet size holes in the banjo bolt combined with the super restricted kinks in the hose right after the turbo built up the pressure in the turbo itself and blew a seal. This resulted in all of the oil being dumped on the ground. I spent the next two days getting the VF11 fitted in. It didn’t just slot into the intercooler, so I had to do some awkward silicone work to it and change my intake set up.
On my personal set up, I didn’t have time to run coolant to my turbo, so I actually just ran without coolant for a week before I had the time to run coolant. I just turbo timed the car (idled it for 45 seconds before I turned it off) and kept in mind some key facts about oil. Conventional oil begins to coke at 230°F and synthetic oil cokes at 275°F. I was careful to not push the car hard for long periods of times so the oil temps would stay as low as they could be.
Tapping off of my heater core lines was very easy. All I needed was two barbed tee’s with two 3/4″ and one 1/2″. The heater core line running into your fire wall on the left is the feed, and the one on the right is the return. Take some hose cutters and clip the heater core lines pretty close to the inlet. After cutting it, insert the tee as shown below. You’ll be able to see in the pictures better then I can explain in words.
For the coolant return, I used the remaining tee barbed fitting and I tied that in where the hose bends just before the coolant return at the block. Refer to the pictures for a better understanding.
The stock idle air control valve on the Ej22E points straight out and goes into your intake. When a turbo is put in the bay, it sits right in the way. This is where you need to get an Ej22T IAC. It routes the line off of the valve up and around the turbo and as you can see on my set up, right into a port on the intake.
Valve cover breather ports are positioned on either head and need to be covered. As a very short term solution, I just went to a trusted auto parts store and bought cute little pod filters and stuck them on either port. This will do for now until you are able to do a proper oil catch can install for you full PCV system. Read about the importance of catch cans here.
But after only 1000 miles you can see that oil has soaked these filters and there is no where for the blow by gasses to vent properly. I’ve also found that boost pressurizing my crank case and causing he oil to squirt out the filter and even push my dip stick up. Installing a check valve after the PVC value will help, as the PCV’s are known to leak. Then just a proper oil catch can set up is important. I would get an oil catch can right of the bat for the build. My article will explain the importance.
Making the intake took longer than you would think. The best way to do this would be to take a piece of tubing and weld one port on it that you can plug your Idle Air Control into and another for your PCV from your oil catch can. You will also need to get a MAF adapter plate to mount right before the pod filter. Then just go to your local auto parts store to buy a pod filter, a bunch of intake bends, and assemble it.
Now you want to know how much boost you are running, right? So it’s boost gauge time. I first put my vacuum line on the pre-throttle body vacuum port. It’s placement there wouldn’t give me a reading unless the throttle body was slightly open. Kinda annoying. The absolute best way to get a reading on your vacuum is to tie directly into the intake. Luckily, there are two ports for additional vacuum lines just sitting there. The only problem is the fact that they have not been taken out of my car for 202,000 miles and are made of brass. Therefore, they don’t come out and just strip. Luckily, heat is your friend. So torch the fitting till it will spin out. This is where it gets weird, for some reason Subaru uses British taper threads on these intake ports. So I had to go to a hose and fitting store to buy fittings to adapt it to what I had. Another option would be to just tap the port to 1/8″ NPT and just thread a barb in there. But I didn’t want to tap the port when I could just get fittings. The fittings I got where 1/8″ barbed adapter, 1/8″ female – 1/8″ female, Male British parallel to Male NPT all 1/8″.
Now we can talk about engine management. Yeah… so… that’s it. There is none. Some people talk about spark plugs and a lot of people went a stage colder. This helps transfer heat from the combustion chamber to the cylinder head better, but can create a sluggish feeling down low in the RPM range. I got the factory stage NGK iridium’s and have been running those with 6 psi of boost with no problem. For safe measure, I re-gaped mine down to .034 which is a popular gap for Subaru guys on higher boost applications. By no means is mine considered a high boost application, I just felt the the stock .044 gap was massive. I would rather be safe and prevent blowing out the spark do to boost.
I bought an AEM wide-band oxygen sensor just so I could keep an eye on AFR’s. If the AFR leaned out, I could back out of boost. Using the wide-band, I can see what everyone means about how the stock ECU can handle the boost. My engine is super happy at 6 psi, staying at 11.5-12.5 AFR. I’ve been thinking about maybe bumping up to 10 psi, but I first need to get a manual boost controller.
I got an ebay stage 2 clutch, and it hasn’t been holding up to the power. It doesn’t hold during a launch the way I would like it to. I would recommend running a Clutch Master’s FX250; this will for sure hold the power you will make off of a waste gate build (or more), but remember not to get too horny for that boost. These motors can only be pushed so far. I have been pushing 6 psi without a problem, and I also know a guy in Georgia running 12 and he says it’s fine. That is a little too close to the edge for me to feel comfortable, this is my daily driver after all. The thing with the naturally aspirated Subaru’s is the are very aggressively timed. Without a way to adjust your timing, the higher your boost is the closer you are to pre-detonating. If you are looking at the next thing to do after the turbo, the very first thing you are going to want to do is find an ignition control device. The Ej22E with PROPER ignition control can handle 14-18 psi. I know a guy that finally blew a ring land at 22 psi after a couple months, but this was with the best ignition control device on the market the (J and S knock-safe and Water/Methanol injection). I’ll be bumping up to 10 psi, and I’ll have an article about manual boost controllers at some time soon. All in all, the compression ratio mixed with this low boost setting makes this car an extremely fun drive. It sounds great, it feels great, and it pulls on Ej20 WRX’s. Yeah, crazy right?
Thanks for reading guys. I had so much fun doing this project and have had even more fun reaping the benefits of boost. I’d be more than happy to answer any questions you have about doing this yourself, and if I missed some things let me know and I can add some sections in. Don’t forget to drop a comment at the bottom to let me know you stopped by, and keep an eye out for updates on the build and to read the Random Facts and Things to Learn page!
And a huge thanks to my wife for editing all of my terrible grammar mistakes. I’m just a
mekanic, mickanik, I fix cars… and only attempt to write…