Ok, I've just finished breaking in my Atkins rebuild. Now I'm ready for some boost. I have been getting 3 psi but that was fine for break in. I started going through the troubleshooting guide on http://www.autosportracetech.com/RX-7/rx7stuff.htm
and I disconnected the vacuum line on the CCA. I found no vacuum so I left it disconnected. I went for a drive and I get 10 psi boost ! I reconnect it and I'm back to 3 psi. Anyone know what's going on here ?

 

Sounds like the CCA is malfunctioning and staying open. If the CCA stays open some of the pressure made by the primary would back-track to the secondary, and if there was enough pressure it'd go right out the intake, wouldn't it? (Just a guess based on knowledge of seq. system. Sorry if thats horribly wrong.)

 

Right, I'm looking at the manual now. The primary can vent boost to the secondary if CCA is open. Maybe I'm getting boost to the vacuum side of the CCA ? Then disconnecting the line makes it atmospheric so the boost closes the CCA and gives me full primary boost ?

 

Got it. The check valves to the vacuum chamber were wrong. No vacuum = open charge control = primary vents to secondary = 3 psi boost max. Got 10+ now, gotta do the hd boost controller.