Joe, you sure it's 3.1 and not 3.3? I'm certain there isn't a gauge that is super accurate, but in reality, I really was looking for a range. Since it came up, what a perfect opportunity to ask. If I have mine set around 7psi, I get crazy boost spikes up to 21psi in between shifts (auto). The ECU catches it, but it feels like I lose performance (maybe timing pull) while it gets the boost back under control. The 21psi part is what scares me. Any higher and I think I'll start having palpitations. Meh...what I really need is to get this thing tuned.