My buddy has a YZ450 with a FMF powercore 4. I think it has a powerbomb header. Anyway the bike is absurdly loud. I realize that it is supposed to make quite a bit of noise but when he cranks it up you feel it in your chest. We live in a neighborhood and have to ride through it to get to our riding spot. I saw that FMF offers a quiet core insert (item# 040171) Is this a good solution to quiet it down? Are there any good alternatives? Thanks in advance.