It's a 3 bar (new last year) and shows like -0.9 when the engines off, while the SPA gauge shows 0.0. They seem to be off by 2 psi or so. I called SPA about it and they said that all gauges varry, which I can believe as tire pressure gauges are always different.

Both connections are at the same spot on the manifold ( in the four tap holes)

I guess my question is with my chip and fueling per boost level.