My friend has a 400ex and he want's to know which pipe is the best for it for maxium power for the money he likes the yoshimura but he said it's pretty high.what about big gun and white brother's. anyone one have any pic's of a yellow ex's i like them.

 

Curtis Sparks Makes the most power and White Brothers is right behind it.

 

www.atvnews.com did a shootout in the June issue
you should check it out