I just did this on my S4R.
You'll have to remove the crankcase breather box, and top the hose off with a filter -- I bought mine from K&N along with the pod filters for the throttle bodies.
I also bought a pair of OEM velocity stacks off a DMF member (eBay would prolly work too) for $25 and cut off the flairs. Total cost: $120.
Bolted everything up and I've been enjoying the induction noise ever since!!
![Evil](http://ducatimonsterforum.org/Smileys/classic/evil.gif)
...and I doubt I'll ever notice the loss of a few HP on the top end.