TurboXS HPBC!! what's its maxit can boost?? got problems

[Dugi]

I have a turboXS HPBC. first I had a problem with my acuator cause when I raised the boost it wouldn't hold. It would like peak at 15 then drop back to 7. Now a have a other actuator and it started out with 3 psi. then I turned the boost up with like 9 turns of the screw counterclockwise and I got 11psi steady all the way. I put like 2 turns more and it dropped to 9 psi. so did I get to the max of the boost controller?? it's about 8 psi more then from the actuator. any leaks or some kind??

thanks

Doug

[Dugi]

ooh I forgot to mention it's the top screw that has to be adjusted right?? and not the one on the side?? I bought this off of someone so I didn't get any instructions.