Headers are exhaust system components that sit at the end of the engine.
if you're buying headers as a performance mod (and if you don't know what you're getting yourself into, chances are good that you can't afford these parts and should look for cheaper alternatives). if not, we recommend against it. if your car doesn't make noises like rumbling or knocking and gas isn't shooting out of malfunctioning undercar parts (like fuel pressure regulators), don't worry about it.
what does putting headers on a car do?
headers are traditionally used on high-performance vehicles to contain the engine's exhaust inside the vehicle, in order to reduce backpressure to facilitate smoother engine performance.
a standard header is “a welded, tube assembly which transfers exhaust gases from the cylinders of an internal combustion engine (usually a gasoline) to an exterior outlet”
the aftermarket generally offers three types of headers for cars – forged steel; cast iron; or mandrel-bent stainless steel. a forged steel header will often give you more power than cast iron, but it doesn't retain heat well and may warp over time. a mandrel-bent stainless steel header retains heat better than other options and usually won't warp due to thermal
do headers add horsepower?
headers do not provide an increase in horsepower, but they can make a car feel faster thanks to the oxygen it lets into your engine.
the short answer is no. there are several reasons why headlight don't increase horsepower. the first is that engines emit gases as a byproduct as they operate and as these gases exit the combustion chamber they push against the piston's exhaust valve. in order for this gas flow to be unrestricted, there needs to be sufficient room under the pistons or headlight which prohibits air from exiting through the valves and escaping out of them without taking enough with it and slowing down what's coming next in line. the other reason why many engineers do not think headers would increase power plant output is because turbo
do headers make a car louder?
headers will not increase the noise level or volume of your car. most people think that just because their car is louder, it's better. this is simply not true
you should care about power gains, though. with more exhaust gas exiting through less restriction (due to the headers), there is essentially more air for the engine to use which equals more power. this can also result in an improvement in fuel economy provided you tune your carburetor appropriately after installing the headers so there are no vacuum leaks and everything else fits securely back together again correctly.