boost creep is when the wg simply cant flow enough pass the exhaust housing to prevent the turbo from creating more boost. it can depend on wg size, wg placement, and exhaust flow. you can actually stop boost creep by adding a muffler or cat if you dont have one and cant afford a larger wg lol.
Turbo Turtle Garage
Zetec and Duratec Turbo kits, engine building