Combination of a pressure relief valve (controls creep and onset) and a coarse and fine pressure regulator (controls the boost signal) in combination with the stock N75 seems to be the magic combo. One way valve paralleling the regulators dumps wastegate signal on shifts or vacum for instant spool-up when back on the gas. Boost levels adjustable as well as boost onset. Go here for a complete article on this system:
http://www.autospeed.com/cms/A_0670/article.html http://www.autospeed.com/cms/article.html?&A=0685

BOOST MACHINE FAQ BY CHRIS: PLEASE READ!!!
http://www.personal.kent.edu/~cplasket/BMFAQ.htm

Good explanation of how it all works here:
http://forums.audiworld.com/tt/msgs/1191014.phtml

Spiking explained:
http://forums.audiworld.com/tt/msgs/1207854.phtml

If you would like to purchase one of these pre-made, contact me

Plumbed in is a 0-30 PSI pressure regulator between the N75 boost line and the N75 body. Left wide open, this will pass all boost and N75 will work as designed.