Best HP mod?
I know tune is a solid hp gain,
I know headers are also another solid one,
I just got my C63 tuned by Weistec a few days ago and love it so much.
But besides headers I'm wondering what will gain significant hp....
I will eventually be doing headers but for now I'm thinking of tampering with the exhaust for a quicker and cheaper mod.
Secondary cat delete is what im thinking of doing....
Just Lookin for experiences of other people's best hp mods of messing with the stock exhaust.
Thanks!!


