The main reason to fit the full system is to gain a nice boost in the midrange. This will be best achieved with the improved fuelling a pc111 or pcV can give.
You'd notice a significant gain right through the rpm range if you went from stock or slipon to a full system, believe me it is very noticeable, but you need a pc for the full benefits.
A PC111 for an R1 04-06 can be picked up 2nd hand cheaply on ebay. There's also plenty of free maps available.
Dek
Dek,
Thanks for the information. I was looking around for alternatives as the Scorpion Serket end can I ordered was taking an age to come and I nearly cancelled the order but I've just received an email telling me it been shipped and should be with me tomorrow, so I'll be sticking to just changing the end can for now.
I, like you, would love a new BMW S1000R, but unlike you, I can't afford it at the moment.
Enjoy your new bike. I've signed up on the S1000r forum under the same user name as I use here and am enjoying reading all the posts (with a hint of jealousy though!!!)