These flange are custom made to matte perfectly to your collector piping or Y pipe, or any pipe with the diameter listed. Simply weld them into place then use a 1″ 3/8 hole-saw to easily drill for your wastegate. The flange will guide the blade and you will get a perfect transition.
They mount the wastegate close to the piping, help a lot especially when you are tight in space for your application.
All flange are CNC machined out of Mild steel.
I have flange cut for 1.5″, 1,75″, 2″, 2,25″ and 2,5″ diameter.