Originally Posted by Solracer
That is a internet myth, back pressue is a bad thing to have in an exhaust period, ask that questions to some of the People from SMSP or Hytech and the will laugh at you.
:werd: and the only reason smaller piping can be better in n/a exhaust (like why you don't want 3" on your D15) is because appropriately sized piping speeds gasses out of the piping, removes areas of turbulence/eddies in the giant piping. NOT backpressure.