hello people , im planning to uipgrade full exhaust on my 89 rx-7 6port n/a
i want some sugestions , if y want to build a headers to improve power , (2 -2) just similar to rotary works ). wich would be the large of the tubes? it's 2" for the headers and 2.5" for the rest of the pipe ok?? im planning to make it here in Argentina, or you suggest me to buy a rotary works headres?

the technical quest is about the headers , large thik of the walls, or something to have to look at in order to build a propper and good header

thanks!

 

I talked to Stan at SDJ a LONG time ago and I believe he used 1 7/8" primaries collected into 2.5" single for a street setup if my memory serves me right.