I just replace the Drummer exhaust on my 09 with a Barker. The ECM is set up for the Drummer. I have a 08 with a Barker and the correct ECM set up. I took the 09 for a ride today and found the bike felt like it had more lower end torque! The 08 I have has always felt like it was more touquey then the 09. But now they feel the same. I am going to send the ECM back to have the correct map installed. The reason I replaced the Drummer is because I have bottomed out twice on the Drummer. I have never bottomed out with the Barker.