KA-T wastegate problem, huge power loss.

[s13koupe]

driving turbo is a big headache. Here's my problem. When ever I hit full boost and the wastegate is open, I notice major major loss of power. But if I step on the gas lightly to keep the boost steady at 4psi and not open the gate, the car is running fast, but once I floor it and the gate is fully open, my car just die off. I have the dump tube open to atmosphere, all I heard is loud noise and No power. I have my car boosting at 7psi right now with FMU and walbro fuel pump. I'm pretty sure this has something to do with the wastegate, either I put it in wrong or vaccum is not right. I have the vaccum line hook up to the turbo compressor and I mount the wastegate on the manifold. My next decision is to move the wastegate to the turbo exhaust flange. Tell me what should I do to get this baby running good 7psi. Also, I've try to set my boost at 4psi and it still do the same. No power on when wastegate open.

My setup: Ka24de
t3/t04e 50 trim 63 A/R
Log manifold
tial 38mm mounted on the manifold
Voertech FMU 8:1
Walbro 255 hiflow
270cc
FMIC

[meme]

is it your clutch slipping? is the rpm just going up and the car not going any faster?

[s13koupe]

clutch is not slipping, like I say, if the gate dont open, the car runs really fast and turbo spool nice.

[Evil S14]

its seriously just your imagination, i feel the same thing, when the wastegate opens as long as its still hitting the desired amount of boost, then everythings okay, the problem is ur just used to it pulling hard up to that set amount, but when it hits that its not pulling anymore, i bet if you put it on a dyno it would read fine