MINI Cooper S - Annoying Brake Judder

Q
I have just fitted Green Stuff pads and drilled and slotted discs from EBC, but I now find that there is an annoying noise from the wheels when I exceed 30mph and there is a slight judder on the steering when braking at speed. I have stripped them down again, but can't find anything wrong.
It has just passed the MoT with these discs, so the efficiency is okay. It is a Cooper S 2004 (June). Do you have any ideas please?

A
We contacted EBC who explained that it’s likely to be poor fitting that is leading to the brake judder. Discs need to be fitted with a limited amount of runout - any more and it will develop judder. Runout is the amount of sideways movement in the disc as it is rotated. EBC recommend a maximum of two thousandth of an inch (two thou) This can be measured using a dial gauge, which is available from tool specialists such as Draper (www.draper.co.uk) for £26.84 (stock number 51830). You'll also need a magnetic stand, which costs a further £29.99 (stock number 45276). The disc needs to be turned a bolt hole at a time and measured for runout and fitted in the position with the least runout. This information is in every disc manufacturer's fitting instructions but everyone ignores it and then complains when they have a judder problem after approximately 2-3000 miles.
EBC told us the noise you are experiencing is the grooves on the disc. It will never go away completely but may reduce over time. The only way to solve it is to go back to plain discs.