Coil curves are made from equipment performance tests. By increasing the range you move away from a real equipment to a hypothetical equipment. Finding real equipment that even works at the extremes may not exist. You should find out what the real equipment would 'do' if faced with an extreme.
Âhi ,
I've used a dx-coil from data sets available with the ep program .
I've increased the maximum and minimum ranges for the coil curves . Does this cause any changes to coil performance  ?