How? I've been reading that the only way to make a ton of power on these engines is not with more boost but more timing and fuel. The stock turbos are almost out of their peak efficiency range as is, especially on the RS models.
That said, I'm still trying to figure out how AMS got their R60RS with bolt ons, stickies and skinnies, and a tune to do 10.2 @ 138 or something silly.