Ok so first off ill tell you about my set up i have a half bp engine fcd stock ecu with a piggy back hks fcon i know i should have a stand alone. But before you say i do have a megasquirt just not the gm sensors. So anyway to4b with a 1.00 exhaust ar 50mm wastegate turbo xs boost controller no emission no rats nest. Heres the problem before i rebuilt an ported the engine i was a streetport with this same set up an never had this problem ever. It would boost 10 11 psi on my old set up. But now i cant even get past 5psi. I checked my boost controller opened it up an cleaned the ball an spring all good. I checked my wastegate an its all good an smooth. When i bought it it said it had a 10psi spring an im thinking there lying. I changed my uim gasket an it sealed not vacuum leaks an i cant find any boost leaks. The turbo has very little up an down an non in an out. My tps is set to 1.3 volts cause i have a little bit higher idle. But i dont have a idle problem some times it starts to drop but its not very often. Does anyone have any idea or had this problem

 

check the waste gate might be staying open or not sealing all the way. If all else is the same, might also be (just guessing) the fact you opened up your intake ports is allowing the engine to breath better not causing as much flow restriction. less flow restriction equals same CFM less psi just guessing.

 

never really thought about that with the porting. but its not my wastegate i have it dumped so it would be a huge exhaust leak. I found today that its not my boost controller. im thinking it could maybe be something with my intercooler or maybe my turbo.

 

its always a posibility