Well that thing should flood right out with alcohol even on the leanest settings, 8 or 9, providing your fuel pump keeps up.
Check the FP and see if it keeps up.
You probably need more boost.
I guarentee you that with that turbo and 21 PSI of boost pos F is way too much fuel without alcohol.
You do have the screens out of the stock maf, yes?
If it were mine I would be running 24 psi.
42's are easy to tune. Lucas 009's, yes?
It really sounds like it is falling flat on it's face overrich, try the leaner settings and manipulate the alcohol flow.
If that doesn't get it then I would start looking elsewhere for problems.
Steve