Easiest way is to install a pressure controller in the line between the wastegate actuator and the intake manifold. This restricts the wastegate starting to open until pressure reaches a high enough level to start leaking past the controller and cracking open the wastegate. Makes the wastegate operate in a more on/off fashion instead of starting to crack open as soon as boost starts to build.

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown