Hi,my name is Mike and i live Montreal.I have the same exhaust set up then you except for the y pipe(topspeed n1 y-pipe) and i hear some rasp over 4000rpm...just want to know the difference with you,it is my y pipe?the rasp started 1 month ago with the Berk hfc installed on the car and 1 week later with the topspeed n1...same rasp! Let me know if you have a Q for me bud,thanks in advance!!by the way do u speak french?sorry for my english! Mike