does any body know any about these if they really work or are they just another gimmick

 

I have one on my Z400 & personally I think they work. The idea is a stepped header. Just like on V-8 engines, good brand headers are stepped. They are smaller near the port & get increasing larger. The idea is for more power everywhere. Smaller exhaust ports are better for torque & larger for high end HP. So, by stepping the exhaust velocity you get the best of both worlds.

Two stroke engines have used this technology for years in the form of powervalves. When closed the powervalve partially blocks the exhaust port giving the engine enhanced low end power & as the rpms build, either vaccum, cetrifugal, or electronics open the valve exposing more & more of the port until it's fully exposed at top rpm for all out horsepower.

I hope this all makes sense to you.

 

cool thanks for the info