the q45’s brakes are not larger than a 180sx. 180sx are 280mm and so are q45’s.
Honestly, IMO, unless u are tracking ur car hardcore just get 180sx brakes. the extra size will add enough for braking. If u go to Z32 u need it all the way around and its a good idea to get the MC because the stock one isnt designed for brakes that size.u can lock up 180sx brakes on the highway
Just something to think about, u dont need 4 piston