I just bought a GReddy Profec B SpecII and I was reading the install book and I saw that it said to hook up one of the tubes to the fuel pressure regulator. Just wondering, why is that?

 

IT needs to be a clean vacuum/boost signal. Since any EFI turbo car will have a fuel pressure regulator, it's easy to tell people to hook to that. IT was designed for many different apps, so they cant give a specific point on an intake manifold or the like. Basically it can get signal anywhere after the throttle plates on our cars.