If you have a desire for maximum speed, you are likely spending much of your time trying to figure out how to add horsepower to your engine. Speed and power are closely related, which means that maximizing horsepower could result in a significant gain in speed. When looking for ways to optimize power, you may come across things such as:
- Add a high-performance cold air intake
- Install a high-performance exhaust system
- Add a water-injection kit
However, many people find that one of the most effective ways to increase horsepower is to add headers to the engine. Headers make it easier to remove harmful exhaust gasses from your engine, thereby improving its efficiency. Many have reported that headers increased both the power and torque on their engine.
Below, you’ll find a guide telling you everything you need to know about headers and why they are a useful tool to help increase horsepower. We genuinely believe that after reading this article you’ll be able to make an informed buying decision and determine if headers are an ideal way for you to increase the horsepower in your car.
What Are Headers?
Exhaust headers are bolt-on accessories that car owners can install to help improve the performance of their engines. By installing exhaust headers, you are aiding your engine in its ability to push gases through the cylinders. Doing so alleviates excess back pressure in the manifold. Instead of pressure building up in the manifold from multiple cylinders, each cylinder receives an exhaust pipe using a header.
Manufacturers will cut and bend headers so that they are the same length as one another. Doing so ensures that exhaust gasses are spaced equally throughout the headers and released at the same time. If the length of the tubes were inconsistent, then there would be back pressure in the cylinders, which could cause a wide range of problems over time.
Most critical is the fact that pressure in the cylinders reduces engine performance considerably. Engines cannot make excess exhaust without risking catastrophic failure. Thus, when headers remove the exhaust, there is a surplus of clean air, allowing the engines to increase horsepower production. That’s why many drivers notice that an engine with headers is more powerful and has higher torque.
There is a direct correlation between engine speed and flow rate. As engine speeds increase, velocity tends to decrease because of the diminished flow rate of clean air. A set of headers works to counteract this problem. By improving the flow rate of fresh air into the engine, velocity will increase as engine speed increases.
Because headers improve the air efficiency of your engine, they could be a worthwhile investment that saves you money in the long run. For instance, if you purchase headers, you won’t need to concern yourself with buying air filters nearly as often. So, even though headers may have a hefty up-front cost, they could cut your costs in the long term.
It’s also worth noting that if you purchase or add other modifications to your car, headers may be necessary to help you alleviate exhaust problems. For instance, things such as the ignition-spark timing or compression ratio could change higher RPMs. Headers may be an essential addition if you wish for other modifications on your car to work.
Many car owners will also likely find that adjusting the length of the pipes could impact their effectiveness. For instance, shortening the header pipes could transfer the torque to above the peak. That means that there will not be a significant shift and the RPM point where the peak torque occurs. If a car owner were to lengthen the pipe, it would have the opposite impact as shortening them.
Cars Racing In The NHRA Use Headers
image via: pixabay.com
Another example of the effectiveness of headers is the fact that National Hot Rod Association recently took steps to regulate headers on its “Funny Cars.” The organization sought to control the angle of the headers, limiting them to no more than 32 degrees. They also determined the maximum header pipe O.D., ruling that it could not be more than 2.75 inches.
Lastly, the group said that the header height must be constant beginning at eight inches below the header flange. That prevented drivers from using stepdown headers as a means to gain an advantage. The organization has said that they will continue to monitor the effectiveness of headers to determine what if any, rule changes they must make moving forward.
Headers have only become popular in Funny Cars over the past few years. The organization said that they instituted regulations to control the continued potential cost of development. According to Jack Beckman, a driver on the circuit often credited with creating the first laid-back header said that the swept-back headers cut nearly a second off of a car’s time.
Additionally, studies showed that the performance gap between dragsters and Funny Cars closed after drivers began using headers. It “narrowed from two-and-half tenths of a second to two-tenths or less at most races. The use of headers was growing significantly within the sport, becoming more and more ludicrous to cut down on drive times.
The fact that the NHRA regulated headers merely means that they are admitting that headers are a useful tool that could help increase horsepower, and thus speed. Beckman continued to say that there are stringent regulations on things such as blower openings, injector openings, and fuel width. Adding headers to this list just meant that his team would have to find another creative way to shed time.
By making this comment, Beckman proves the point that headers are one of many ways to increase horsepower and speed in an engine. While they are not the only tool available to do so, they are one of the most effective. The fact that the NHRA took the time to pass down stringent regulations proves that headers can help increase horsepower considerably.
A Header’s Effectiveness Depends On The Engine
While there’s no denying that headers can help increase power, the amount in which they can do so depends significantly on the engine type. Thus, it’s imperative that you find the headers best suited for your engine before making your purchase. For instance, the consensus is that smaller-diameter headers are ideal for mild street engines, as they build more torque and midrange engine speeds.
On the contrary, large-diameter pipes feature power increases with higher RPMs, killing low-end torque in the process. So, when choosing headers, you should make sure you select the right size for your engine. Failure to do so could end up causing more harm than good, putting unnecessary stress on your engine. The right fit, however, could increase horsepower, no matter the size of your engine.
When choosing headers for your engine, we recommend trying to stick with top brands, including DC, Gibson, and BBK. All three of these companies produce high-quality accessories well-known throughout the automobile industry. You can’t go wrong with choosing one of these brands, so long as the header is designed to fit in your engine properly.
We recommend speaking with a customer service associate at your local automobile store to help determine which headers are best for your vehicle. Another option you have is to read through customer reviews online. These also can give you an idea of whether a particular set of headers will work with your engine.
There are also a couple of calculations that you can run to help determine the peak torque RPM and proper header size for your engine. First and foremost, you can calculate the peak torque RPM, which allows you to identify the cross-section area for the first pipe. To do so, take the central pipe area, multiply by 88,200 and then divide by the displacement of one cylinder.
You can also take the time to determine the required displacement of one cylinder. You can do so by taking the peak torque RPM, dividing by 88,200, and multiplying by the movement of one cylinder. Then, increase this figure by the total number of cylinders in your engine to determine the primary pipe area for your entire unit.
Lastly, you can determine the displacement of one cylinder by taking the primary pipe area, multiplying by 88,200, and dividing by the peak torque RPM. The first two equations will allow car owners to determine peak-torque RPM if they have already purchased headers and know the size of their engine. The last equation is beneficial if they know the peak torque RPM and the engine size.
Adding headers could be a practical choice if you are looking to increase the horsepower and RPMs of your engine. Headers can remove exhaust more quickly than a standard exhaust system, which could maximize clean air intake into your engine. Whereas velocity tends to drop at higher RPMs, headers prevent this from happening.
Headers could be a necessary purchase depending on what modifications you’ve made to your car previously. If you are purchasing headers for your engine, be sure you do some research beforehand to determine which type is best for your engine. You should also specify which length is appropriate for your vehicle.