yes it is adjustable, but you have to remove the cooler line to the turbo, heat shield, loosen the two bolts holding the actuator bracket to the turbo and pressurize it with air. once you do that you can rotate it. i have egr so mine is harder to adjust. w/o egr you may be able to remove the bottom where it attached to the wastegate and turn that.
i have mine set at about 28 stock, and use a needle valve to bleed off extra when i want to make more boost. that way its easier to adjust quickly.