I have a 09 155 Dragon talked to lots of people out west I have installed a SLP ypipe,pipe and can, Delta 3 reeds,stock springs on clutch, Big throut by SLP air kit and installed extra air vents in dash so it can breath running 62 gram polaris weights and its very responsive good power. Run it against a friend of mine with a stock 800 dragon 155 at around 9500 ft there is a major difference. He has ordered all the same parts that I have in mine now we will see next week as we are going back out west.Too bad you need to stick $1000.00 to make run real good.