Increase brake disc from 280mm to 300/320mm

[CrashW]

Hi there,

My Focus has the standard 280mm discs but with the 18inch alloys and the discs look like toys. 
 

I’d love to upgrade these to 320/300mm discs that will fit in my alloys.  Is the only difference the caliper carrier bracket or do I need new callipers as well? I think the 300mm discs use the same callipers but I’ve not seen anything on the 320mm. 
 

Has anyone done this, any advice?

 

Thanks

 

A

[BigLen]

Bigger discs also contribute to the vehicles "unsprung mass" just like the 18" rims, in turn will further impact on the take off speed. 

A good upgrade to the existing discs and pads are EBC Green stuff