OK, so this has probably been beat to death but, I plan to finally go aftermarket (due to crushed stock head pipe). The DR.D sounds like the best one for the YZ but my question is did any of you guys have to do any major jetting changes after installing this pipe? I realize that it will depend on my elevation, etc. but I am currently running the 48/170 that most people recommend and it runs great. Any help would be greatly appreciated.