Maybe they provide one that big so later on if you want to upgrade it will be sufficient for larger boost levels? I don't know.
2013 Audi //RS5 Phantom Black Current
2009 e92 ///M3 Jerez Black<~~Sold
2009 Audi //S5 Phantom Black<~~Sold
2002 e46 ///M3 Carbon Black <~~Sold
2007 Audi //RS4 Dolphin Gray<~~Sold