I have a 2000 XR650R uncorked with the XR's Only competition exhaust. Nice pipe by the way. It has the power disc system on it. I decided to remove all the disc and take it for a ride. HOLY COW WHAT A DIFFERENCE! The bike was a friggin fighter Jet compared to a cessna prop plane. Loud as all heck but what a difference. I know this subject has been beat to death over and over but anyone have this exhaust with the 12 disc system on it? I was under the assumption that the disc system would give it plenty of power and still be soemwhat quieter than the stock drilled exhaust. WHat other options have people used with this exhaust pipe? any option from XR's Only other than the disc set that gives it more power? After I rode it with the exhaust disc out of the pipe it would bring the front end up in fourth quite easy but sounded like my crf450 with the fmf titanium 4 exhaust which was just as loud. I know there are a few bolt on goodies you can get for the competion exhaust. Just want to know who has tried what and their thoughts on it. one more question with the disc system. which way do you install the disc? with the cup side towards the exhaust pipe or away from it?