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The easiest way to get more power from your engine is to let it breathe better, increasing intake and exhaust flow. Factory exhaust systems are compromises, with noise reduction usually a priority over performance. Installing a performance exhaust system should be the first step to improve flow, but if you want to go further, mount a set of headers in place of your exhaust manifolds. Most stock exhaust manifolds are very restrictive; when designed more attention is often paid to engine compartment fit than exhaust flow. Headers reduce restriction and enable your engine to make more horsepower.
Factory log-type exhaust manifolds are especially restrictive because all of the exhaust pulses dump into the same small space. In contrast, an exhaust header has individual tubes so each exhaust pulse can flow freely from the exhaust port. While some OE manifolds have individual runners, they are usually small in diameter and make sharp bends that restrict flow. Headers generally have larger diameter tubes, plus the tubes are mandrel bent, which ensures the diameter remains the same through the curvature of the tube. Flow is increased throughout the length of the tube.
Besides less restriction, headers can also increase performance because of the “scavenging” effect. Individual tubes all meet in a larger tube called a collector. When an exhaust gas pulse exits a header tube into the collector, a negative pressure wave is created that travels back up the header tube to the exhaust port during valve overlap. This negative pressure helps pull any remaining exhaust gas from the cylinder and can help draw the incoming intake charge into the cylinder. The scavenging effect makes more power, but how much and in what rpm range depends on the length of the header tubes.
Headers come in a number of configurations, including short tube, or “shorty” headers, mid-length, and long tube, also called full length. In general, it's usually easier to achieve the aforementioned scavenging effect with long tube headers, but there are also shorty headers with equal length tubes. Long tube headers require that the exhaust pipes be cut and a connection made with the header collectors, and we offer a complete selection of flanges, gaskets, and reducers to accomplish this. The tubes on short tube headers generally fit more easily in the engine compartment and some are designed to connect to the existing exhaust pipe flanges, so no cutting or welding is necessary. We also offer short tube headers that come complete with catalytic converter.
On most headers all 4 pipes end together in the collector, but there are also so-called “tri-y”, or 4-2-1 headers. On the latter, the opposite cylinders in the firing order are paired in a short “Y”, and then the Ys combine in the collector. No matter what your performance goals are or what you drive we have the headers for the job, including EPA and CARB compliant street headers, block-hugging street rod headers, headers for use with turbochargers, headers designed for low-end torque, high rpm headers for every type of racing, and much more. We offer headers in stainless steel, steel that's been coated to prevent corrosion, and even titanium. Stainless steel headers will not rust but they may turn blue near the head flange. Ceramic coatings are durable and can withstand high temperatures.