The stock wr450 was like an XR250, it was a dog. I have a 250f also and it is a fast bike not doubt, I don't think my WR with all the mods is THAT much faster, more torque, faster, yes, but not blown away power difference... maybe I need the pipe. My 02 YZ250f with a DR D pipe wheelies through 3rd wr does the same but with more torque but it is not so hugh as to be blown away. I think I need a pipe. My WR has ais, snorkle removed, throttle stop, didnt do grey wire yet.... we'll see. I want more out of it for being a 450, it should be a bit faster than just the free mods I've done so far. That is just being straight up honest. But I will have to check into pipes and see if they make a huge difference. I don't need power super low just lower mid to high. It is a great bike though.