I have the supertrapp 4" aluminum racing series with the diffuser disc system. I have not had any problems with mine and have had it on the quad about 4-5 years now. Here's a link to what it looks like Text I've never had a problem with it, I love the sound it makes, it's not loud and it can be repacked.
According to Supertrapp, it really needs to be repacked when it starts getting loud. LIke I said, I love the sound it makes (a soft rumle) and it's not loud at all. I did rejet my carb after I put the k&n on it. I went with what the kit recommended and am very happy[img]i/expressions/face-icon-small-smile.gif[/img] with it.
This may not work for everyone, but it has worked for me and I am pleased with the performance of my quad[img]i/expressions/face-icon-small-happy.gif[/img] Lt. Dan

 

my suppertrapp pipe is stuck. i put the silencer onto the expansion chamber and it wasnt quite right. now it wont come off!!! i bend the flaps of the stainless out abit but theres another layer on the inside. please help i even heated it abit. wont come off!!!!

 

anyway at my last wits end my dad saw a can of dw40 and said males try. and to my surprise after about a minute it slid right off. that stuff is amazing i swear by it now. that my pipe still doesnt fit that good we had to modify the braket and mount it on the inside instead of the outside of the frame bar.