Alright, so my MAP sensor's ground was kafuct. I pulled the electrical tape back about a foot to find some shotty wiring, and even after that point I still didn't have a ground. So I chopped the wire before the shotty-ness and grounded it to a bolt on the firewall.

Fast forward an hour, and I'm screaming down Victoria at full boost. What a fracking feeling!

A HUGE thanks goes out to Stephen Richardson, who walked me through the electrical diagnosis over the phone this afternoon, as well as bouncing ideas with me the last few weeks. Thanks for the rest of you guys for your ideas, and Salomon, Rob, and Ryan who I also bugged directly for some insight! Boost on!