I have a 2010 FLHTK and the heat was almost unbearable. I live in California and it get's hot in the summer....The first thing I did was remove the cat. I went with V&H Power Duals and Hi Out-put slip on's, I also did a stage one and added a PCV. The heat was greatly reduced. Can"t say how much the PCV and stage one alone added to controlling the heat, as I did it all at once, but I can tell you as a combination the heat was greatly reduced. In my opinion it was very much worth the money. Not only did it cool the bike (but understand it still get s hot...it's a Harley), but the motor runs cooler which helps the life of the motor, and my wife was most happy...happy wife, happy life!