I was messing around with this the other day and found out something interesting.
If you swap lines 5 & 6 (if I remember correctly)
And then do the hose 10 mod.
You will see the turbos boost up to 23-24 psi, it did not trigger error 66 either.
Obviously running this high boost on a stock engine is tempting fate, but it did absolutely rip
This was on my rev a gtb