I finally found a TW locally that was a good deal. I too would like to know what is recommended for extra power, without sacrificing reliability and too much fuel economy. My bike has had work done to it, including a 225 head/piston, K&N filter (cut up airbox), and 250 Ninja muffler. I had just begun to research the modifications when I found this forum. I would love to hear opinions on whether or not these things are harmful to the engine or even worth the extra noise that the different muffler makes. Any input would be great. Thanks.