EJ20Y Baja Turbo Swap!

General talk about the Subaru Baja.

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Alcyonex
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EJ20Y Baja Turbo Swap!

Post by Alcyonex » Tue Jun 18, 2019 6:16 am

Here’s some quick info on swapping the EJ20Y from the Japanese 2.0L Legacy twin scroll engine.

List of EJ255 Parts you will need:
A/C Compressor
Coolant Temperature Sensor
MAP Sensor

List of Misc Parts you will need:
High Pressure Fuel Injection Hose
Vacuum Hose
Coolant Expansion Tank to Radiator Hose Adaptor
Misc Coolant Hoses to Adapt
(not sure if thats everything)

My swap for the Baja came with the transmission, so I had to get the ‘04-‘05 Spec B engine and trans combo. My particular swap costs $1200 for the engine and trans combo, and about another $1000 for different peripherals, such as new plugs, timing belt kit, power steering lines, misc hoses and connectors. It also cost me about $400 to have it E-Tuned to run on the factory ‘04 Forester ECU I have to run my COBB AP. The car will run in its basic format, but I had Intake, 3” Exhaust, Grimmspeed EBCS, etc... so a tune is necessary.

In stock format,
The ‘04-‘06 Baja Turbo will mate up to the ‘04-‘05 Japanese 2.0L Legacy Spec B without much work. After removal of the engine, the EJ20Y (manual transmission engine) will only need the wiring harness, coolant temperature sensor, MAP sensor, and fuel pressure regulator from the EJ255. All the other sensors are plug and play. If using the engine in its complete format, you will have to make or buy a downpipe for the TD04HLA turbo that comes on the EJ20Y engine. (Note: the EJ20X/Auto, comes with a smaller IHI VF38 with the same flange) AVO TURBOWORLD (https://avoturboworld.com) does sell complete downpipes that will work with this swap for roughly $800 or just the flange pipe adaptor for $300. I personally, prefer making my own much cheaper. I did get a 6” chopped part of the downpipe, with my engine, to mate up to my HKS downpipe I already had. All I did was cut my HKS downpipe about 3 inches higher than the bottom of the EJ20Y downpipe piece, then place the factory DP inside the HKS and tack weld it. I then cut vertical lines in the cut end of the HKS DP and crimped it in to the factory DP and welded it all up. I had to make a couple of minor changes in the exhaust trajectory by cutting and bending the HKS DP, due to the turbo mounting angle. This keeps it from hitting the bottom of the car with my full 3” exhaust.
I also used everything except the A/C compressor, coolant temp sensor, wiring harness, and MAP Sensor from the EJ20Y. I have not figured out what and how to swap the A/C compressor lines to match up with the EJ20Y A/C compressor. However, the power steering pump is easily adapted by using the '06-'09 USDM Legacy Pressure Line. I picked up mine up at AutoZone for $50 bucks and swapped it in 20mins. The MAP Sensor from the EJ255 needs removed from the throttle body and placed inline from a vacuum line. The FPR just needs placed inline after the return line (the bottom of the 3 hard lines) and the dampener/hardline return.
The rest is plug and play & bolt-on.




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Last edited by Alcyonex on Tue Jun 18, 2019 6:16 am, edited 2 times in total.

mike-tracy
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Re: EJ20Y Baja Turbo Swap!

Post by mike-tracy » Tue Jun 18, 2019 9:05 am

How does it run with the exhaust AVCS fully retarded?

I swapped that turbo to my Legacy with all the extra hardware, and had an aluminum elbow made to connect the cold side. I am a fan, it both spools faster AND has more top end than our cheesy td04-13 turbos we got here.

I later found out that there are companies that make a td04-19t cover "straight" inlet so you can reuse your stock intake parts. Maybe someday I'll switch to that
1992 Legacy SS, 5mt and heavily modified
2000 Impreza RS Coupe, RSTI swap in progress
2003 Baja, 4eat & NA. Bone stock and loving it!

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Alcyonex
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Re: EJ20Y Baja Turbo Swap!

Post by Alcyonex » Thu Jun 20, 2019 10:34 am

With the exhaust cam retarded 1 tooth on each side, it had no torque what so ever.
Based on the recommendation from my tuner, I set the timing back to the stock setup, and it runs great now. Plenty of torque again and the tuner is still working on a custom setup for me. Right now we’re only on a 12psi 91 octane setup to start. Then we will go to 93 octane higher boost and eventually an E30 mix.


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mike-tracy
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Re: EJ20Y Baja Turbo Swap!

Post by mike-tracy » Thu Jun 20, 2019 11:47 am

That's awesome to hear! I had thought about an ej20x swap on a 4th gen LGT, they are only a couple wires away from running the ej20x ecu. It is a badass motor.
1992 Legacy SS, 5mt and heavily modified
2000 Impreza RS Coupe, RSTI swap in progress
2003 Baja, 4eat & NA. Bone stock and loving it!

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Alcyonex
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Re: EJ20Y Baja Turbo Swap!

Post by Alcyonex » Thu Jun 20, 2019 12:09 pm

I wouldn’t say it runs as good as the ej255 when it worked well, but I like torque, and the 2L is weak in that dept. it’s good enough for the price and I think it has more potential


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mike-tracy
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Re: EJ20Y Baja Turbo Swap!

Post by mike-tracy » Fri Jun 21, 2019 3:21 pm

It's not an option for everyone, but I took an ej22 NA short block and matched that to ej20 wrx heads. I rebuilt the bottom end, while reusing the same pistons. It's not as torquey as an ej25 of course, but with the higher compression and the smaller td04-19t turbo it's miles better than the ej20 it replaced.

The ej20x should have 9:1 compression and my build has 9.5:1 approximately. There is way more torque than the 0.2L increase in displacement would seem to yield.
1992 Legacy SS, 5mt and heavily modified
2000 Impreza RS Coupe, RSTI swap in progress
2003 Baja, 4eat & NA. Bone stock and loving it!

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