I have a 99 kdx220 with the desert (rev) pipe on it and at one time I did have the turbine core2 silencer on it, but with it on the jetting was pretty fussy and it didn't really make anymore noticable power, however I do also have the RB carb mod so that had a little to do with the fussy jetting, anyways I run the stock silencer now and it's the quietest one out there and you don't have to repack it. If you really want more power don't waste your money on a silencer, get the carb mod. oh and you will notice a big gain in power from the fmf rev pipe.