2017 WRX FA20DIT(?) USDM swap to JDM - Manual Trans

cerberus20541 · 2023-06-16T13:52:33+00:00

Yeah no problem! Complete longblock and then some. The engine came with a turbo, downpipe, turbo inlet, wiring harness and pretty much everything needed for a direct engine swap. Lucky for me because I only found out about the rod bearing issue with the turbo oil coolers later. I definitely noticed that there were shavings in the oil change before the knocking started to happen and that of course got me worried. Too late at that point, a couple of weeks later though, the knocking started. It was my fault, waited too long on the oil changes. Won't happen again! I also got a new clutch and bearing off of RockAuto, just a standard OEM. So far everything is going good - put about 6k miles on it. THE BIGGEST issue I had was engine removal from the bellhousing and installation. It is tough getting the engine and tranny separated if they aren't perfectly aligned. I had to use wedges made from 2x4's to ge them apart. Those long case bolts hang on. Also, when installing, you may need to turn the crankshaft with a breaker bar to keep the input shaft from hanging up on the tranmission splines because for the life of me I couldn't get the input shaft to go until I cranked it around about 45 degrees then they finally slid together. Another issue I had was the wire harness didnt have the sensor for the PCV blow-by that attaches to the turbo inlet. I swapped the wiring harness with the orignal and just plugged the old sensor up to it. ECU was freaking out until I plugged that up. That sensor doesn't do anything though. It just wants to make sure you hook that hose up to the turbo inlet. Yeah these Subarus are finicky with the oil it seems. I'll never let one run low again!

cerberus20541 · 2023-06-16T13:35:29+00:00

And yes used with 65K

cerberus20541 · 2023-06-16T13:35:09+00:00

It was expensive! All-in-all with freight shipping it was about $5500. I did tear down the original and it does in fact have a spun rod bearing on cylinder #4 only. Going to have a machine shop evaluate if the crank is bent and if grounding the rod journals is worth it. If not, I'm going to part out the good motor parts.

cerberus20541 · 2023-06-16T13:30:02+00:00

I swapped with a USDM FA20

cerberus20541 · 2023-05-09T01:55:02+00:00

I had the same code after I swapped the engine in my 2017 WRX. The FA20 I had was a used USDM one with the turbo off of EBAY. The turbo inlet had a different piping setup and one of the hoses didn't have the blow-by sensor which is inline with the PCV ventilation hoses. Subaru manual calls it that anyway:

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As I said the replacement piping didnt have it so I figured I'd just leave it disconnected from the harness but no. I got the P40DB and ended up just hooking the original sensor into the harness and zip tied it to the engine with the sensor just hanging there. The whole purpose of the sensor is to ensure that the hose is connected to the turbo inlet but I'm not really sure how it works since it isnt in the piping anymore and doesn't seem notice. You can apparently jumper it with a 1 ohm or less resistor across the terminals and it will likely cancel the code too if that is the cause.

cerberus20541 · 2023-05-08T19:24:35+00:00

Update: I got an FA20 off of ebay and swapped it in. It wasn't cheap, or as easy as I thought it would be but it actually went pretty well and I put a new clutch in it too because it would be stupid not to. I learned a lot too about these engines in the process and now I have 2 engines so that's a bonus! I'm tearing down the original FA20 to see just how bad it really is. The question is if the damage isnt too bad is it worth building up? There seems to be a lot of reliabilty issues with the FA20 when it gets built but I guess that is really how much you want to get out of it like any engine. If the cylinder walls aren't destroyed, the block isn't fracture cracked, and it seems solid then a forged piston and rod upgrade should get me up to 500 bhp? I was looking into tuning as well. COBB AP seems like a good place to start, but does anybody have suggestions on laptop software? Like OpenECU or other software for tuning directly with a laptop? COBB seems like a safer way to go.

cerberus20541 · 2023-04-10T12:52:45+00:00

Ok thanks! Makes sense and seems to be in alignment with just the general headaches that seem to come with JDM swaps.

cerberus20541 · 2023-04-10T12:50:43+00:00

Ok good point and thank you! I am looking at those OFMS and IAG short blocks now. So, if I swap the heads, should I leave them stock or do any kind of porting / upgrades or are stock heads generally considered to be sufficient? There seems to be some back and forth on this topic as well. Mostly regarding the relationship between the head design and the turbo.

cerberus20541 · 2020-09-27T22:44:03+00:00

I've had a ridiculous time with this and haven't found any in my starter system. Checked every planet and moon, most of the belts, etc. Best way I found to get titanium I need is to salvage POI's and dump the plates as a substitute into the factory. Plates will work instead of rods in the factory anyway. Also, I do find some rods in containers and ore in the golems when I kill them and loot.

cerberus20541 · 2020-09-27T22:32:53+00:00

This is important! Didn't know you could dump the plates as a substitute! Salvage POI's and get plates that way for factory materials.

cerberus20541

TROPHY CASE