Recently "upgraded" to the Fab9 Stage 1 intercooler from the standard Flyin Miata IC that comes with their turbo kits. Added a few inches of additional intercooler piping length on each side to reach the more forward mounting point of the Fab9 as well. After these changes I'm seeing a peak boost of 6-7psi when I saw 7-8psi before. Is it possible that adding the slightly larger intercooler and intake piping volume is dropping my peak boost by this much? In my understanding the turbo is pushing the same amount of air into a larger space, causing a pressure loss in the system. Anyone seen this before?

 

Intercoolers have a pressure loss when going through them. I'm not sure what the pressure drop ratings are for either intercooler but that could be the reason.

 

You need to move your wastegate reference to the coldside of the pipe. https://www.miataturbo.net/diy-turbo...eed-ebc-47532/

 

IF your turbo has the headroom to do so — if you’re seeing 12psi manifold pressure, the turbo is outputting 14,15,16 psi (depending on pressure drop) just don’t run it off the map