I've done a search and I cant find what I'm looking for. I have a stocker on my 450 right now. I've riden a stock 450 with a thunder alley and it's great. All I hear is how great thunder alley is. The question is, does anyone have any real data on different pipes? Specifically I'm looking for dyno information on the thunder alley, yosh, DR.D, GYT-R and Jardine. Preferabaly with stock header for a base line. Has anyone done this kind of test or comparison?