Change to ventilated brake discs?

I have a 2001 K11 with the 1.0L engine. I now have solid (single disc) brake discs and was planning on replacing the front wheel brakes.
I saw that I could get ventilated disc brakes for my car, but will they fit without having to change the brake caliper?

certainly not.you have to get the whole package both discs and calipers

And go up a wheelsize 13" to 14" > for clearance (if you have not gone to bigger wheels already ) N14 1.6l calipers & discs fit with a 1mm washer used as a spacer between calipers on the 2 x 17mm bolts roobarb.

Lol why? It's only a 1.0L! Pushing what 35hp?

I was just wondering since they were actually cheaper on ebay than the singular ones

going by these measurements roobarb http://www.micra.org.uk/threads/brake-upgrades-what-are-my-options.53445/#post-548434
the 247mm brakes should fit under your 14" wheels :)

you can also fit the 257mm ones in 14inches..well they leave little clearance but they do fit in my alloys.of course it has also to do with the wheel offset and design but if you use 247mm you will be fine with any 14 alloy wheel