Exhaust flap mod??

Hi guys

im having an Akro slip on fitted tomo by BMW but ive been told its not that louder than a standard exhaust.
Now i know the best thing to do is get a full system but my budget doesnt really allow.. I have been reading of this mod thats big in the states where you bypass the flap in the cat which gives a slightly more raspier note on idle?
has anyone done it? do european RR's even have it?

heres the link to what im talking about
http://www.s1000rrforum.com/forum/s1000rr-do-yourself/743-exhaust-valve-mod-little-more-rumble-idle.html

thanks guys

Sorry admin, i posted this in the wrong section so ive moved it to the garage. But cant see how to delete this?