Embodiments relate to a dilator and catheter introducer systems. The dilator system includes a dilator including a dilator lumen, and one or more cores for positioning in the dilator lumen. The catheter introducer systems further include a sheath including a sheath lumen operable to receive at least a portion of the dilator therein. Each core imparts a curvature to the dilator； modify the bending resistance of the dilator, or a combination thereof.
