On the akrapovic site it lists the new system...LA said:If you look at the Akrapovic web site there is no system listed for the s4rs and what is listed for an s4r is under the "street legal" catagory. Probably not very loud at all. I looked for an Akrapovic system and couldn't find one for my old s4r or my current s4rs. So, I got the termi kit. Love em.