What is the best bolt on exhaust system for the 2006 r6. I am looking for a little better mid range and volume

Answer 1

Your best bet is to sell your bike and buy another 600 or the Ninja ZX-6R 636 as the R6 is known as a screamer with no low-end and only moderate mid-range. In the 2007 Cycle World dyno testing the R6 finished nearly 5 HP below all the other bikes at every RPM point until well over 10,000, which makes it the hardest bike to ride fast consistently. Apparently Yamaha had a buy back on the 2006 R6 because it didn't meet the claims they had made in advertising.
As for exhausts, I'd stick with those you can mate to a power commander http://www.powercommander.com/powercommander_iii_usb/powercommander_all_downloads.aspx?mk=15&mdl=123&yr=2006