Your vehicle uses a four-stroke combustion cycle: the intake, compression, combustion, and exhaust. The engine repeats this cycle to generate power and move the car ahead. If any stage of the four strokes is not efficient, it puts stress on the engine that could increase fuel consumption or increase the engine’s wear and tear.The exhaust manifold comes in the last stage of the cycle. You may often hear car mechanics suggest replacing the exhaust manifold with headers. Here are some reasons why you should consider their advice.
What Is an Exhaust Manifold and Its Function?
In vehicles, the exhaust manifold collects exhaust engine emissions from multiple cylinders into one pipe. The part is called manifold because it folds several inputs and outputs together. It acts as a funnel where the engine emissions are collected and burnt before they are sent through the exhaust pipe.
Exhaust Manifold – Problem With the Design
Exhaust manifolds are made of cast iron. These components have thick walls as they have to withstand high temperatures and pressure. One of the problems with cast iron is that it has a higher tendency to crack, which can cause exhaust gases to leak. It can lead to the release of harmful emissions into the atmosphere and increasing air pollution.
The second problem with exhaust manifolds is that since their walls are thicker, the pipe’s inner circumference is smaller, which leaves very little space for the engine’s emission to pass through. The surface of cast iron is rough, which causes resistance to the passing gases. All this leads to a collection of exhaustion gases in the chamber and causes backpressure. It also prevents exhaust from clearing the gases efficiently. The result is there is a loss of horsepower as fresh air cannot enter the engine chamber.
What Is a Header?
A header or an exhaust manifold header is a bolt-on accessory that improves your vehicle’s exhaust system. The primary goal of replacing the exhaust manifold with headers is to make the engine’s job easier to push exhaust gases out of cylinders. The header is made of stainless steel with a smooth surface inside and outside. Hence, it does not create additional resistance to gases passing through the exhaust system.
Header – Good Design
If you look at the header design closely, you can see it has separate tubes for each cylinder in the engine, further connected to a collector pipe. The tubes are smooth and equal in length. The header’s design ensures the exhaust gases reach the collector separately, and there is no backpressure on any cylinder of the engine. According to experts, if you replace the exhaust manifold with an aftermarket header, you are more likely to experience improvement in your vehicle’s performance.
Types of Headers
There are two types of headers available in the market- Short tube headers and long tube headers.
Short-tube header – they are ideal for idle to mid-rpm range. They have shorter tubes in comparison to the long tube headers. You can opt for an equal or unequal length of headers, as they are great for turbo-engines.
Long tube header -they are ideal for mid to high rpm range. They are loved for their aggressive noise. If you want to install a long tube header, you need to replace three things – the exhaust manifold, the catalytic converter, and the downpipe. Talk to a professional to find out whether a long tube header would be suitable for your vehicle.
To sum up, besides the engine performance, the header’s installation also gives your vehicle a characteristic sound of your engine. The exhaust manifold absorbs most of the sound and pressure from the exhaust. Installing a header will help you hear increased engine noise as you accelerate. If you like the engine’s roaring sound, the header is the right accessory for your car.