Ok so I have a buddy who isn't on the forums very often. He is running a 2.5" pulley with a corsa 2.5" exhaust. Lots of cooling mods and a custom tune by someone. He is probably goign to be going to a 2.7" or 2.8" pulley with 50shot. He wants to know if the weapon r race header would be good to run with this, or should he change to a complete 3" system(downpipe and catback). Basically when does the 2.5" piping start holding power back.

bump for thoughts.