Your absolutely right we are moving from Yamaha Jr. and its can to Yamaha Sr. and the pipe. We have been practicing with the pipe for a while now and she loves it much better mid-range and a little more top end not to mention the can sounds obnoxious and sprays oil all over everything. So yes I know the pipe is worth almost 2 seconds on our track but do you think it makes a difference to how the motor is made? I have 2 Woltjers engines and Daniel asked what we ran so at that time we used a can and that’s what he built them to do.What can really change? They’re the same specs right? Would he have made changes if I said a pipe?( I GUESS HE WOULD SINCE HE ASKED) Maybe I should call him to find out. 1 of them needs to be sent back to him for a rebuild so I guess I will find out if it is faster then it was when it was built for a can.