Originally Posted by Dan A
I'm guessing the OP didn't follow through on his plans :P
Having come from the Volvo world, I can share with you this:
He's using megasquirt which I presume you would also have to use if you really wanted to go this route successfully. Then again I don't know what is possible through openport tuning as that's not an option yet with Volvo.
Thanks for the link! Unfortunately there is almost nothing meaty in it, but still good to know someone else did it successfully, and says this consistent with the other folks whom have done it.
You don't need to use megasquirt on the turbo subarus. But we only have provisions for controlling one wastegate solenoid, so you would either have to have static, manual, or additional electronic wastegate control of the second turbo. He did what a lot of the gasoline compound guys have done, which is to have the little turbo hit 18, then have the little turbo drop to something like 5 or whatever wastegate spring pressure is, as the big turbo rises to 13. So he is indeed WAY under capacity. There are a bazillion ways to plumb a compound system, but there are ways to do it that make boost shockingly stable, flat, and easy to control. It's not hard to see why OEMs are adopting the technology.
If I ever do this project, it will not be for a while at least. I am very slow at doing anything, and I have a lot more important fish to fry.