Headers 101

When you’re looking to increase your engines performance, it can become a never-ending task. Knowing your vehicle still has room for performance gains, it’s hard to stop pushing forward. When deciding what modifications should be done, performance exhaust headers should be at the top of your list. In this article we will go over what function headers play in your vehicle, and the benefits of installing performance headers.

What are Headers?

MAGNAFLOW Short Tube Headers
MagnaFlow Short Tube Headers

Headers remove anti-performance exhaust dirt in your vehicle, making sure your engine’s potential is fully maximized. Additionally, headers reduce exhaust backpressure for air to flow more easily out of your engine. They work by providing each cylinder with its own mini exhaust pipe and piping exhaust pulses away from the cylinder head into a downstream exhaust collector, improving air intake and exhaust.

How to spot failing headers

A large reason many upgrade to performance headers is for hp/tq gains. However, many also decide to upgrade when their OE headers start to fail. It’s important to know the signs of a failing header to prevent engine damage.

Engine noise

Your exhaust may leak out from your header if it becomes damaged or loose. If you hear a hissing or tapping noise from your engine, you have an exhaust leak. This sound would be clearly audible when you cold start your vehicle, or accelerate.

Unusual smells

An unusual smell can come from your engine compartment if exhaust leaks out from your header. The heat from a failing header or even an exhaust manifold can cause nearby wiring and plastic components to melt. Sometimes these smells can be accompanied by light smoke which is a serious safety hazard, and should be addressed immediately.

Fuel efficiency and power

Engine performance issues can 100% be expected when your header is failing. If your vehicle’s power, acceleration, and fuel efficiency drop suddenly, you may need to replace your header. When this is occurring, you should immediately have your vehicle checked over before any further engine damage can occur.

While some of these signs and symptoms can fall under other major vehicle issues, it’s always recommended to have your mechanic look over your vehicle before purchasing new parts. Furthermore, your mechanic and tuner can help you best decide which new components would work best for your vehicle.

Performance Headers

aFe Y-type Headers
aFe Y-type Headers

Like all factory components, they are only designed to work alongside factory parts and stock performance levels. The moment you start upgrading your system, things can begin to fail with the rest. First and foremost, your modified engine produces more heat. Heat can be a major killer. Luckily, aftermarket performance parts are designed to withstand higher heat levels.

Increased Air Flow

Performance headers are manufactured to allow greater air flow. Factory log-type exhaust manifolds are restrictive because all of the exhaust pulses dump into the same small space. Exhaust headers have individual tubes so exhaust pulse can flow freely from the exhaust port. Some factory OE manifolds have individual runners, however they are generally smaller in diameter and make sharp bends that can restrict airflow. Headers in most cases have larger diameter tubes, and are mandrel bent. This ensures the diameter remains the same through the curvature of the tube. Flow is increased throughout the length of the tube.

“The Scavenging Effect”

Aside from less restriction, performance headers also increase power because of the “scavenging” effect. The individual tubes of your exhaust header meet into a larger tube called the collector. When the 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 amount of power gained from this effect will depend on the length and type of headers you choose for your vehicle.   

Aside from these benefits, there are many others to gain when upgrading your headers.

  • Increased Fuel Economy
  • Amplified exhaust tone
  • Weight reduction
  • Increased horsepower & torque

What kind of Headers should I buy?

Headers aren’t a one size fits all product. They come in different shapes, sizes, and finishes to suit your vehicles specific needs. Leading manufacturers also produce headers in various configurations, specially tuning each to fit the type of engine its intended for.

Perrin Equal Length Headers
Perrin Equal Length Headers

Knowing the basics of each header will help you greatly when browsing. You will come across short tube aka “shorty” headers, mid-length, and long tube aka full-length. Additionally you will come across unequal length and equal length,”tri-y” or 4- 2-1 headers, and many different finishes.  Each design impacts back pressure in the exhaust system in a different way.

Shorty Headers

With shorty headers, the port pipes actually merge into a single exhaust pipe in a much shorter distance. This style header performs best in the idle to mid-RPM range. They are the recommended header for vehicles that rely on low-RPM power like a daily driver, or a work truck that sees a lot of towing and hauling.

Full-Length
HOOKER Long Tube Headers
HOOKER Long Tube Headers

With full-length headers, the exhaust pipes are much longer and merge further out. Longer port pipes result in lower exhaust back pressure. As a result you will have improved oxygen intake and a boost in horsepower.

Tri-y Headers

Tri-Y header is designed to match the synchronization of the engine firing order, thereby maximizing exhaust scavenging. The opposite cylinders in the firing order are paired in a short “Y”, and then the Ys combine in the collector.  This design creates the optimum torque and greatest horsepower gains in comparison to any other design. 

4-2-1 Headers
Invidia 4-2-1 Design
Invidia 4-2-1 Design

As the name implies, the headers start from 4 pipes that merge into 2 pipes and those merge into 1 pipe. For most vehicles, this design produces more mid-range power wit the sacrifice of top end power. This is great for the street, since when daily driving you normally do not redline. Instead, you’re keeping the revs somewhere in the middle, usually shifting at 3-6K, and this is where the headers shine. However, be advised that not all 4-2-1 headers produce more mid-range power at the expense of top end. It’s important to read into each individual header to understand its capabilities.

Equal Length vs Unequal Length
FLOWMASTER Unequal Length Header
FLOWMASTER Unequal Length Header

An equal length will expel gases at an equal rate per pulse. Gas from each cylinder leaving the header at the same time. The benefit of equal length is the balance of back-pressure at the exhaust ports, which will improve volumetric efficiency and overall top end performance. With an unequal length header, gas from the two longer runners will remain in the header as it will take longer to reach the collector. Unequal Length Headers are typically lighter since shorter runners on two cylinders require less material. For those enthusiasts hoping to shed every ounce of weight from their car, this can be a huge advantage over equal length headers

These are just a few common types of headers you will come across when browsing for your new upgrade. As we stated earlier, when looking to upgrade, you should speak to an experienced mechanic and your tuner. When discussing your performance goals, and your vehicle’s current modifications you can choose the best one together for your needs. If you currently don’t have a mechanic, you can always reach out to one of our representatives at Sport Compact Warehouse, we have decades of speed-shop knowledge.

In Conclusion

Headers are one of the most affordable and easiest engine performance upgrades in the market. The benefits will help your already installed aftermarket components perform to their highest capability and achieve maximum performance.

Now that you know the basics, you’re ready to get out there and start your hunt for your newest upgrade! Here’s a list of leading manufacturers;

AFE Power

MagnaFlow

Borla Exhaust

CORSA Performance

Hooker Headers

Flowmaster

Invidia

Perrin