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How Much Horsepower Do Headers Add? (Quick Answers)

Whenever it comes to enhancing the performance of your vehicle, you might have thought of headers. Generally, headers help the engine to push exhaust gases to exit the cylinders.

So, headers are pretty efficient for better performance of your car. Moreover, headers also help to improve the sound of your car.

But you might be confused about how much horsepower headers add. Generally, the more horsepower the headers will add, the more fuel mileage will be required.

So, you have to decide economically about the headers. Most times, headers improve the engine performance worth the horsepower.

How much horsepower do headers add?

Generally, a set of headers will add 10-20 horsepower. Moreover, how much horsepower headers will add depends on the type of headers. If the headers are long tube headers, 20 to 30 horsepower will be added. But if the headers are short tubes, 8 to 15 horsepower will be added.

However, you might use the headers in different places. So, the horsepower consumption might also be different. Let’s see how much horsepower the headers will add in different places.

To a chevy 305:

Chevy 305 is one type of engine developed between 1976 and 1992. So, the engine is not so modern and produces high efficiency. That’s why you might need to add headers to improve the engine performance.

Generally, a good quality set of headers will add 10 to 20 horsepower to the engine. So, you can also install headers for better performance of the chevy 305.

To a 318:

Generally, 318 is the type of engine that you might not improve much with headers. With a quality set of headers, you can’t add too much horsepower to the engine. 8 to 11 horsepower will be added to the 318 if you install headers.

To a mustang:

Headers enhance the performance of a mustang excellently. Generally, the mustang engine is one of the most efficient engines for cars. So, when you add headers to the engine, the performance is even more.

Because a good set of headers will add up to 30 to 40 horsepower to the mustang.

To a 4 cylinder:

Generally, a 4 cylinder can make up to 80 horsepower on its own. But if you install headers to the cylinder, these headers will add some more horsepower to the cylinder. So, the performance of the cylinder will be even more.

Generally, a good set of headers will add 10 to 20 horsepower to a 4 cylinder. 

To a 5.3:

A 5.3 is one type of chevy engine that makes high horsepower and has a better performance. But if you still want to add some more horsepower to the engine, you can add headers to the engine.

If you add headers to the 5.3 engine, the headers will add 15 to 20 horsepower to the engine. So, the engine will perform better than before.

To a 5.7 Hemi:

A 5.7 Hemi is a high-performance engine. But if you install headers to the engine, the header can add 35 horsepower to the engine.

How much horsepower do long tube & shorty headers add?

Long tube and short tube headers are different because of the length of their exhaust port pipes. Generally, the difference in length has different impacts on the exhaust system.

The long tube headers generally add 20 to 30 horsepower to the engine. Since the length of the exhaust port pipe is larger in long tube headers, these headers are suitable for high-rev vehicles. Moreover, they provide high horsepower without other modifications.

On the other hand, short tube headers don’t produce as much horsepower as long tube headers. They might provide 8 to 15 additional horsepower to the engine.

Generally, short tube headers are suitable for cars that rely on low RPM. Moreover, short tube headers are not that difficult to install.

How much HP does open headers add?

Open headers are one of the most power-providing headers. Generally, open headers will add 30 to 40 additional horsepower to the engine. This range is pretty large compared to the long and short tube headers.

Generally, open headers will make the engine louder also for their high efficiency. So, the sound is so loud that you might not hear the voice of another person in the car.

When we want to make out car’s engine perform better, we install headers. Headers add some horsepower to the engine additionally and the performance gets better. But with the performance, the mileage and the sound also increase.

So, when you will install open headers, they will add 30 to 40 horsepower. This range is so big a margin that the sound of the engine will also increase and might disturb you.

Do headers make your car faster? What headers add the most horsepower?

Yes, headers make your car faster. But headers alone can’t make a car too faster. Headers generally modify other systems to make a car become faster. For example, headers will increase the performance of air intake, engine tuning, etc.

But the main function of headers is to add some additional horsepower to the engine. You might know that the more horsepower, the better the engine will run. So, headers generally add 10 to 30 horsepower to the engine according to the type of engine and type of headers.

Some headers might not add more horsepower. But some headers will add a large margin of horsepower. For example, long tube headers and open headers add the most horsepower to the engine. But open headers create a loud sound that is a great disadvantage.

Generally, a quality set of long tube headers will add 20 to 30 horsepower to the engine.

Why do headers increase horsepower?

Now that you know headers increase horsepower. You might want to know the reasons behind it. Let’s see why headers add horsepower.

Increase exhaust rate:

The main function of headers is to push the exhaust gas to remove out from the exhaust system. Headers also decrease the backpressure. As a result, the exhaust rate will be increased. So, better output and horsepower will be generated.

Moreover, the increased exhaust rate will make the overall performance faster and more aggressive.

Sometimes, the increased exhaust rate might increase the sound of the engine. But, the additional horsepower is added because of the improvement of the exhaust rate.

Improve scavenging:

Another work that the headers do is to improve the scavenging of the waste gasses. When you install headers to the engine or cylinder, the exhaust gas will leave the cylinder at a faster rate. This will increase the air intake rate.

That means the high-speed air will create a pressure difference. Then the pressure difference will create a vacuum chamber and it will push out more exhaust gases from the exhaust system. Thus the output and horsepower will also be increased.

Speed up power efficiency:

You might know that the more power efficiency will be generated, the more horsepower will be added to the engine. So, when the headers will make the exhaust system faster and scavenging effective, the power economy will also be increased.

So, ultimately the power that is generated by the exhaust energy will add some horsepower.

Do you need a tune for headers to increase horsepower?

It is not compulsory to add a tune for headers to increase horsepower. Generally, headers will help to increase the horsepower by helping other parts of the vehicle. But if you add a tune, the car will get significantly more horsepower and will be more aggressive too.

Sometimes, installing headers without a tune might lessen the horsepower and with that little horsepower, the performance might not get that better. Sometimes, the headers without a tune might risk the engine with CEL or a lean engine.

A lean running engine will get difficulties while starting the engine. So, if you add a tune with headers, you will get different benefits.

For example, headers with a tune will add more horsepower, reduce the risk of CEL, and make the car more aggressive. So, it will be a wise decision to add headers with a tune.

Final Thoughts

Headers will add 10 to 40 horsepower according to the type of the header. Generally open and long tube headers add more horsepower. But short tube headers don’t add large horsepower. Sometimes, a tune with headers will add horsepower significantly. So, you can also add headers.