Do a search on Edelbrock in the DRZ400 forum. There are dyno graphs to prove my point. Just read this: http://www.thumpertalk.com/forum/showthread.php?t=326332&highlight=edelbrock I read the thread, very interesting. If I had access to a dyno, yes, I could probably realize optimum performance from my bike with the stock carb through jetting experimentation. The Edelbrock is my choice because after it is dialed in, I don't have to mess with it any more. The bike runs clean throughout the RPM range, has pretty flat torque characteristics, excellent throttle response, and improved fuel economy. I ride for fun, too old to race, mostly woods trails, dirt and gravel roads, so the Edelbrock works good for me simply because it provides the performance I like and is never a hassle. Different strokes and all that.