Reverse Boost creep?

[Black_Havoc]

Ok, I've done the free mods and what not to get 12.5 PSI. The weird thing is, 3 days ago, it reverted. Back to factory 9PSI. And it feels like a dog passed 4000. I still level pegged a Z28 through 3rd and 3/4 of 4th then his torque took me. I'm pretty sure I would of staied with him through all of 4th if I had my other 3psi. Anyone know whats going on? I've re-tightened all my intake piping. I dont hear any leaks with my "stethascope" (reads 3 feet of vacuum tubing inserted in ear) around the intake. Is my BCS making it go back down to 9, even though the restrictor is gone? Any help would be great. Getting a MBC next paycheck setting it to 15, will I have the same problem and revert to 12 psi? so then I would have to set it to 18PSI then revert to 15 arg, I'm confused. HELP!

 

[Black_Havoc]

Anyone? Come on, I need to figure this out. One more thing I noticed. When I shut down I hear a whistle, for a good 2 secconds, untill its totally off. Any ideas anybody?

 

[PRESSURIZED]

If you hear a whistle on shutdown..it sounds like you got a boost leak.....do a presure test on the turbo and listen for leaks...make a intake leak tester.