RomRaider

Trying to figure some things out. I have a (USDM) 2002 WRX which is 100% stock, and long story short a headgasket job revealed other big issues. Now, I've got a JDM non-AVCS EJ20 sitting here (codes put it as coming out of BH5B TT Legacy; 9:1 compression). If I move everything over to the JDM long block (sensors, cam pulleys, the works) is there a base map to account for the higher compression (which I think is the only real difference) available for the USDM ECU?

Not chasing every last HP, just want it a solid driver again.

I'm in Ohio where premium is usually 93 octane, if that matters. Pardon any dumb questions... Just evaluating options at this point to get this car back on the road. Currently leaning towards this, as long as I can gain some confidence that it'll run right with the 9:1 engine.

yeah, you got it.

that generation of motor is older 16-bit ecu and isn't flashable. the cam gear uses a different pattern.

you'll use the ej206 longblock and swap the ej205 intake manifold and everything up.

timing and fueling would be adjusted a bit, but to make the most use of the new setup, a full tune would be recommended. perfect platform for Carberry.

Good to hear I'm in the right path with the hardware side of things.

Are you saying that the stock ECU can't be tuned with RomRaider/ECUFlash? This would be the first I've heard that; everything seems to point to it being compatible.

no i mean, the original ecu that the motor cam from is of a different and not conveniently tunable generation. that cam gear on the motor it comes with is matched for that ecu, so you swap yours from the old ej205 on, since it's matched your current ecu, which is a perfect platform for Carberry.

Ah okay, got it. I have to pass a plug-in-and-check-codes emissions check for the county (ugh) so the JDM ECU is out of the question (I'd be tempted to have gone AVCS at that point). Was a little concerned there!

If I got this route I'll take everything that isn't the block and heads from my stock 205 (plus a new clutch, timing belt, and other tuneup parts) and move it to the 206, which was the plan before I realized the JDM block is 9:1 compression - looking into some parts cross-references, looks like even the cams are the same in this JDM block as my stock one so it really will just be the compression shift to address.

I am assuming I would want to go a little colder on plugs than the USDM stock spec? One step? Two steps?

6 or 7 on NGK heat range. 6 is oem, 7 is one step colder.

if you were using a bigger turbo than the td04 to get more out of it in the top end, then 7 heat range would work fine.

.028 to .030" gap. don't scrape the plating on the tip.

Great - thank you! I've got a set of BKR6 and BKR7s on hand, will probably just play it safe with the 7s. I think at this point I've decided to move forward with the swap; it'll be a little while before getting to the actual logging/tuning but I'll be back

So this swap is in, running, driving, and being logged. Stock everything except one range colder plugs (BKR7EIX) and an STi up-pipe (and the extra compression from the JDM engine, of course).

I've created a thread in the 'tuning' forum which seems more appropriate than here; I'll be happy to share the map once I'm done tweaking here if anyone else wants to work from it at their own risk, but at this point I'm looking for some second opinions.

That post is here: viewtopic.php?f=15&t=19218

Just to add to this guys the bh/be rev a and b are both 8.5.1 CP maybe rev c aswell.
the rev d is 9.0.1. that being said a ej206 and ej208 a,b are the same comp as a jdm ej205. possibly rev c aswell. so on this thread CP is a swap and run asuming usdm wrx is also 8.5.1