I had a look on the Eibach part numbers for lowering springs, i30 N vs. Veloster N. The parts seem to be not the same. For front and rear spring. I don’t know if the i30 springs can fit physically. I wouldn’t gamble.
It'll fit but the spring rates won't be matched to the VN's weight and damping. Whiteline also has a lowering spring meant for the i30N but also fits the VN. You can look it up with part #WSK-HYU001. USA's Whiteline website says VN fitment and Australia's website says i30N but yet, same part number.
Eibach took the time to make springs that'll match up to the i30N and VN, which is why there's 2 different set of springs for them. Heck, even the VT springs fit our cars but I definitely wouldn't recommend that. Handling would be terrible.
They have the picture of the N on these springs but they are only listed as Veloster R Spec springs. The R Spec is about 115 lbs lighter than the VN (likely most of it it up front where the 1.6 liter engine is) and the I30N looks to about 115 lbs heavier than the VN so I’m not sure any of these are really right.
The raw weight standards in EU and US aren't the same. You can't compare the weights directly. In EU the standard is 90% fuel, 100% all other fluids, on-bord tools, and a 75kg driver. I think in the US the driver is missed at weighing. @R Veloster N
In EU the gross weight of my N Performance hatch is 1950kg (4299lbs). Max. axle loads are 1090kg (2403lbs) front and 980kg (2161lbs) rear.