I have the follow mods on my 7 hks downpipe, apexi fmic, apexi intake, fludyne radiator, pulleys, hose tech, power fc and my boost is only hittin 8 psi. I check every hose there is and none is disconnected so can someone tell me wat else i need to check. I know i should be hittin somewhere near 12 psi or so. So please help if u can thanks

 

You can have a split in the hose that would cause you to lose boost even if it is still connected.

Turbos?

 

If you are running twin sequential turbos and have not upgraded to the efini Y-Pipe a likely candidate is the rubber boot which connects the black plastic crossover pipe to the turbo Y manifold.

The crossover pipe has two boots. One at the connection to the intercooler and the other at the Y-pipe junction. If the leak is really bad you can hear it. In my case, I could feel the air leaking out at startup idle (3K) and could only make 4 lbs of boost.

If you convert to the efini Y-pipe (available from Mazda competition and a variety of vendors) you eliminate the boot thats hard to get to.

A hint: the efini Ypipe conversion is easier if you pull the front studs using red locktite.

93 Auto-Touring
Petit column mount boost gauge
RP AST
efini Y-pipe
K&N filter
12+ pounds of boost under load.