hI GUYS ! About two month's ago i was asking you wich pipe was the best for the yz-426, and most of you have only good things to said about Thunder Alley. I can now tell you that you were right.The pipe give to the bike a very snappy response, the low end is very responsive, and the mid and top is way better (very powerful) than it was. It rev for ever and don't fall of the pipe and im pretty sure i don't loose anywhere. The quality is very good.And Mr Murray is a very good person to deal with. In conclusion, i recomand the pipe to every one who have a 426 it is the best single mod you can do , with a Quick shot. Thank's to all of you who give me the tips about Thunder Alley.