I'm definately not a mechanic and to some people this question may seem dumb, but what is the difference between headers and the exhaust manifold? If someone could enlighten me it would be appreciated. Thank you.

 

its the same thing. and if its not someone please correct me so i can learn something new.

 

Headers are a form of exhaust manifold. So all headers are exhaust manifolds, but (at least in my book) not all exhaust manifolds are headers.

Headers are made out of tubular steel pipe which (if done right) is bent so the air pathways are smooth and constant diameter for optimum flow. The indidivual pipes for each engine cyliner are usually long (20-30 inches) and then combine into a collector (big tube for all the pipes come together) that is sized and shaped to promote flow. the provide about 5% more power than standard cast manifolds.

Headers have to be made with expensive and time consuming machinery and jigs in a number of steps that bend metal to just the right shape, them lots welds for the various pieces together, etc.

By contrast, manifolds from the factory are usually one piece units cast with exhaust passage through them: Short and far less optiumum for exhaust flow. However, they are cheap to manufacturer (just pour the molten metal, them let it cool).

Given the fact headers provide more power and economy (at least if sized right) and that they don't cost THAT much more, people are often puzzled by why more manufacturers don't put them on production cars. Well, some do--my Porsche came from the factory with a pretty good set of 20inch stainless steel headers.

But, the real reason isn't the cost of the headers, its the cost of the assembly.
Stock exhaust maniufolds on most cars are designed to be installed on the engine before it is put in the car and shaped so they will not "get in the way" when the engine is quickly dropped into the car on the assembly line. By contrast, some headers (example, really long tube headers on a 98 Camaro LS V8) have to be installed after the engine is in the car and from underneath, by hand::: this is WAY too expensive for the manufacturers to do.

 

Ah, I see, that makes a lot of sense. Thank you.

 

the headers allow for a greater air flow and will create better proformance. take a look ath the disign and you will see how a larger amount of air can escape than a exhaust manifold.