A high pressure die casting (HPDC) system for casting ultra-large single-piece castings for vehicles. The HPDC system includes a clear feeding path from at least one ingate to a predetermined thicker section of a mold cavity, a last to solidify ingate having an equivalent or larger feeding modulus than the highest feeding modulus of the other ingates, and thermal management elements. The clear feeding path, last to solidify ingate, and thermal management elements ensure sufficient supplemental molten metal flow to the thicker portion of the mold cavity to accommodate for shrinkage of the thicker portion of an ultra large casting during the casting and solidification process.