I will just riff on what I have so far, hopefully its close to a good answer.
On this chart - the pressures all pretty much track the same, so
depending on how you wanted to use them for tracking effects of changes like CAI or DP they would react the same. The sensor pressures are MAF, MAP, Absolute (in psi), and 2 are derived, Manifold psi is a User math senso wanted to use them for tracking effects of changes like CAI or DP they would react the same. The sensor pressures are MAF, MAP, Absolute (in psi), and 2 are derived, Manifold psi is a User math sensor here, and the last one is Boost/Vacuum, which I believe is ECU derived. But in the end they all tell the same story. Manifold pressure will go negative reflecting transient suction in the manifold. the last one 'Turbo boost' is the classical positive only gauge that most people think of as turbo pressure in the intake hose that doesn't go negative at all, there's always at least a little pressure in the intake tube. So in transient if the throttle plate shuts down, there's potential for a little negative pressure in the manifold, but that's referring to 14.7 psi absolute psi as zero.r here, and the last one is Boost/Vacuum, which I believe is ECU derived. But in the end they all tell the same story. Manifold pressure will go negative reflecting transient suction in the manifold. the last one 'Turbo boost' is the classical positive only gauge that most people think of as turbo pressure in the intake hose that doesn't go negative at all, there's always at least a little pressure in the intake tube. So in transient if the throttle plate shuts down, there's potential for a little negative pressure in the manifold, but that's referring to 14.7 psi absolute psi as zero.
