Fuel Cut?

[sleepydsm]

1992 Tsi AWD 5 spd
255 walbro
afpr
650cc
safc(5 knob)
maft v1.6
3" gm maf
20G w/ external hks wg
greddy type rs bov
correct timing
new wires
new plugs
good coil
good transitor
new ecu caps/good ecu

The Problem: At any boost level above 10 psi in any gear, at about 4200-4500rpm it knocks and at about 5000rpm the whole car jerks and like stops pulling. Is this fuel cut? I have heard that the MAF translators have a fuel cut switch. I honestly know NOTHING about the MAF translator, as I bought the car and it was already set for the 650ccs. I thought it was an ignition problem, so I checked the coil, tried my friends brand new power transistor, and even replaced the ecu caps. And it was none of those. Thanks!!

Also... my fuel pressure is set at ~28psi. I'm guessing its because I have a 255 L/hr High Pressure fuel pump, and the base fuel pressure was turned down to prevent FPR overrun at idle.