tGrey5spd

Ok so may be we all know what a muffler is but what constitutes a header? From my youth I remember a big shiny metal tube mounted underneith the car and visable 'cause it was under the rocker panels. But what is a header really?

KnotBand

replaces the exhaust manifold and turns it from a plenum into a single tube for each cylinder that goes into a larger collector downstream.

Jeremy

It's like longer tubes for better flow.

onefastv6

the exhaust wwants to be able to flow out of the engine fast and easy. but the stock header (or manifold) is often restricted with small pipesor collectors. by buying an after market header it lets the air flow through with bigger pipes and collectors.

tGrey5spd

Thanks guys...got it.