Over boosting problem

[rn240sx]

Well guys, I just now realized that im slowly over boosting..Here is whats going on...

I start slow and go WOT, the boost gauge will spike really fast to my stock 6.5 psi and almost come to a dead stop, but it continues very slowly and i end up letting off the throttle once it gets to 10 psi...The only thing I have done to the motor lately was change out to a different manifold and put on a larger gauge (thicker jacket) wastegate feed line from the compressor..This new manifold is an equal length tubular with the wastegate feed branching off the collector just underneath the turbine flange...I do not have a boost controller, just signal feed from the compressor direct to the side of the Tial as directed..Anyone have any clues?

ThanksRobert98 ka-t