I was wondering if HAN could answer a question for me. What is the difference between one header to the next? I know that there are many brands out there, but I would like to know what makes one more free flowing then another? Is it just because there is a wider diameter then another? Also if you have any other interesting facts about header's do share. Thanks for your help and input.:thumbup:

 

I'm not up to par on header dynamics, but the biggest thing you have to consider with four exhaust valves opening so rapidly, is that the exhaust gasses are pulsating out. Taking that into account, diameter of piping, length of piping, design of piping, piping junctures all most work together to allow those four flows to merge into one as easily as possible. With the oscillating gasses, you can send them into a bit of turbulence by even a slight gouge in your header. It's quite a science to sit down and design one, keeping all those factors in mind.

 

if you want the best header for a sohc engine go with the bisimoto. cant beat the design from a guru of dynamics.