i just took my car on a drive went full throttle right around 25psi i heard a flutter sound at around 7500-8500 rpm and lost power.the problem is intermitant i cant identify if it might be a wastegate issue or turbo issue. car has gt35r with 50mm tial bov and tial 44mm wastegate. car has never done this before and it does it wether i lower the boost or increase.

 

I would check for boost leaks and make sure all the vacuum lines are good. Maybe pull the intake and check the turbo for shaft play if you don't find any leaks.

 

i did a boost leak test that checked out good. it sounds like a really bad misfire when im up really high in the rpms.

 

Could be spark blow out? Have you checked all your plugs? Maybe throw in a new set gapped correctly? Are you using anything to log with?