For many, the C6 Corvette is the greatest American sports automobile ever built. 430 horsepower and 424 pound-feet of torque were factory-installed numbers for the C6 after the mid-production changeover to the LS3 engine in 2008. Those are outstanding stats, there’s no denying it. However, what really sets the C6 apart is its ability to accept even more horsepower from aftermarket additions. Upgraded C6 Corvette headers come into play in this situation.
The LS3 engine is tuned in a number of ways in factory configuration. Even aftermarket parts can’t match the remarkable flow rates of the stock LS3 intake manifold and head. Some elements of the plant design, however, could be improved. The exhaust manifold design of the C6 Corvette is one of such. Adding performance headers to your vehicle is one of the most cost-effective ways to increase horsepower and torque. The exhaust manifold is the source of many of the limitations in the stock C6 exhaust system, and a good set of headers can dramatically improve the airflow of your LS3 engine.
It’s easy to get lost in the vastness of the C6 header universe. We’ll keep things simple for the time being. We’ll focus on what C6 Corvette headers are, the many types of headers that are available, and give some recommendations at the end of this article.
What Are C6 Corvette Headers?
Most C6 LS3 Corvette owners consider installing headers as a first step in their performance modifications because of the increased exhaust sound they provide. You’ll see a lot of talk about LS3 C6 improved headers on forums and discussion boards, but you’ll seldom find out what C6 Corvette headers are or how they function.
C6 Corvette headers are the first part of the exhaust system to be attached to the LS3 engine’s exhaust ports. Because of this, they have a significant impact on exhaust flow out of the engine. The term “headers” is used to denote an aftermarket exhaust manifold in order to clarify terminology. However, headers are often more efficient than exhaust manifolds due to their shape.
To reduce the amount of effort required by the LS3 engine to evacuate exhaust gasses, you should upgrade your C6 Corvette headers. The more exhaust fumes can be expelled, the more power you’ll have. Additionally, improved exhaust scavenging properties and reduced backpressure are critical to performance.
With C6 Corvette headers, each cylinder has its own primary exhaust tube, as opposed to a common exhaust manifold on factory C6 Corvettes that collects exhaust gasses from all of the engine’s cylinders and dumps them into a single collector. This is essential since the overall efficiency of the headers is strongly influenced by the primary tube length and diameter.
C6 Corvette Long-tube vs Short-tube Headers
Short-tube (or shorty) vs. long-tube headers are always discussed in the context of headers. The names of the two entities are, in fact, what set them apart. In comparison to long-tube headers, the primary tubes of C6 shorty headers merge considerably more quickly into a collector. For long-tube headers, the opposite is true.
The LS3 engine’s performance is significantly altered by the primary tube length difference between short and long-tube Corvette headers. Exhaust gasses are released into the headers in pulses as the LS3 in your C6 Corvette is running. Extra power is created at various points along the power and torque curves depending on the length of the primary tubes. Standard shorty C6 headers tend to boost horsepower and torque in the lower rev range by reducing exhaust gas pulse length. Conversely, the exhaust gas pulses are longer with long-tube headers, which push horsepower and torque improvements up the rev range.
Despite the fact that short-tube C6 Corvette headers can provide considerable increases, long-tube headers are almost always recommended for an LS3 C6 Corvette. As far as high-rpm performance is concerned, long-tube headers are the best option. The greater flow of short-tube C6 headers over the stock exhaust manifold is undeniable, but for most people, lower costs and better fitment outweigh any performance improvements.
Catless vs High Flow Cats
There were two or four catalytic converters in the factory C6 Corvette, depending on the model year and where you purchased your vehicle. Corvette C6 vehicles from 2008-2011 featured only two catalytic converters in the mid-pipe; versions from 2012 and onwards included four cats in the mid-pipe. Adding more cats to the exhaust system will inevitably result in a more restrictive system overall. Between the exhaust manifold and X-pipe in factory C6 Corvettes, the catalytic converters are installed. In contrast to small tube headers, large tube headers typically necessitate the development of a new cat solution.
Catalytic converters for Corvette performance headers are normally available in two configurations. C6 headers can be used with or without catalytic converters, depending on your preference. It is vital to keep in mind that being catless is unlawful in most states of the United States. Catless C6 headers and X-pipes are only suitable for off-road use because of this. You won’t be able to pass an emissions test with catless long-tube headers. Catless Corvette headers and X-pipes, on the other hand, will provide the greatest performance boosts.
C6 long-tube headers with catalytic converters installed are also an option. Most aftermarket C6 Corvette headers with catted exhaust systems include an X-pipe as standard equipment. Cats are commonly relocated by placing them inside an X-pipe. Corvette headers with high flow catted air intakes are preferable to those without, even if the improvements aren’t as significant. While still delivering significant boosts in horsepower and torque, they’ll keep your Vette legal.
Benefits of Upgraded C6 Corvette Headers
Upgrading your C6 Corvette headers can have a significant impact on both performance and audio quality. An LS3 header improvement can have a considerable impact on horsepower and torque output. Depending on the type of header you choose and whether or not you run a high-flow or catless option, there is a significant difference in power gains and where in the rpm range the power is generated. You should expect to see a number of simple benefits from upgrading your C6 Corvette headers:
LS3 Corvette Long-Tube Header Gains:
- (Catted) 10-20 hp gain w/ similar torque gain with tune
- (Catless) 20-30 hp gain w/ similar torque gain with tune
- Notable increase in power in the mid-high rev range between 4,500-6,000 rpm
- Reduced backpressure
- Lower exhaust gas temperatures
- Better exhaust scavenging characteristics
- Improved exhaust sound
LS3 Corvette Short-Tube Header Gains:
- (Catted) 5-15 hp gain w/ similar torque gain
- Notable increase in power in the low-mid rev range between 1,500-3,500 rpm
- Reduced backpressure
- Lower exhaust gas temperatures
- Better exhaust scavenging characteristics
- Improved exhaust sound
C6 LS3 Corvette Header HP Gains
Long-tube C6 headers are the way to go if you’re looking to get the most out of your engine. Long-tube headers produce more power because of the effect of exhaust scavenging on primary tube length and diameter. Since exhaust gas is pulled out of the cylinder in a hurry, most long-tube headers are engineered to work with exhaust gas pulses to maximize negative pressure in the headers. For greater performance, long-tube headers excel at utilizing this “scavenging” effect.
Header upgrades can help lower backpressure, which is another important element. Backpressure is created by exhaust system resistance, which can be induced by catalytic converters or oversized piping sizes. By reducing the amount of resistance that exhaust gases face, C6 headers, both long and short, can reduce backpressure. Increased horsepower is the outcome.
Because long-tube headers are better at scavenging and cutting back on backpressure, they tend to provide more performance improvements than shorter headers. Catless long-tube headers are particularly susceptible to this. Short-tube headers, on the other hand, have their supporters. Installing muffler covers is a snap, and the result is a more pleasing exhaust note. However, if peak performance is the goal, they aren’t the best option.
Best C6 Corvette Headers
Let’s take a look at some of the greatest C6 Corvette header alternatives now on the market. Many good choices exist for the LS3 C6 Corvette’s headers because they are so popular. There are catless and high-flow catted header choices available. While long-tube headers are the most popular, we’ll throw in a short-tube version as well.
C6 Corvette Kooks Headers 1 3/4” With High Flow Cats
“Kooks” is almost always mentioned in C6 Corvette header debates after a few seconds of scrolling. They are noted for their high quality and attention to detail in their products. For more than half a century, Kooks has specialized in high-performance heads and exhaust systems for American motorsports.
Long-Tube headers are included in the Kooks C6 Corvette Long-Tube header set. Included are stainless steel long-tube headers with 1 3/8″ primaries and an O2 extension and exhaust clamps, as well as all the necessary hardware for installation. In a nutshell, it includes everything you’ll need to get started.
Additional primary tubes are available for individuals who want to switch to forced induction down the road, such as 1 7/8″ and 2″ primary tubes from Kooks. The 1 3/8″ recommendation is based on the idea that a naturally aspirated engine may be driven well. Large primary tubes will have little to no effect on performance if they are not powered by an external source of electricity.
Texas Speed & Performance C6 Corvette 1-⅞” Long-Tube Catless Headers
Since no cats are included, it is solely suitable for usage on the track, as opposed to the Kooks C6 Corvette Long-Tube option stated above. In terms of LS and LT1 performance parts, both Texas Speed and Kooks have a long history. Their C6 long-tube header set is the perfect compromise between high performance and low cost.
The Texas Speed set is near-impenetrable in terms of materials and structure. Built from 304 stainless steel and CNC mandrel bent for maximum airflow efficiency, the headers are designed for maximum performance. Along with the headers, the package includes an off-road 3″ C6 Corvette X-pipe. Exhaust systems for C6 Corvettes with headers and X-pipes are among the most efficient and least restrictive on the market.
In conjunction with a suitable tune, Texas Speed’s header and X-pipe combo can add up to 20-25 horsepower. As a result, you’ll notice a huge increase in your abilities.
Hooker Blackheart 2005-2013 C6 Corvette Short-Tube Headers
Clearance issues in the engine compartment and under the vehicle are a major concern when using long-tube headers. It’s necessary to make minor modifications to most large-diameter long-tube Corvette exhaust headers to fit in place of exhaust manifolds. In most cases, long-tube headers will also snag on road irregularities and speed bumps. Short-tube headers have these advantages over long-tube headers because they are simpler to install and more convenient to use. The Hooker Blackheart set is an excellent alternative if you’re looking for a C6 short-tube solution.
The Blackheart short-tubes have a major advantage in terms of exhaust velocity, which is good news for low- to mid-range power. The Hooker Blackheart set of C6 headers is constructed from durable 304 stainless steel for extended life and superior thermal dynamics. The Blackheart shorty header was designed to operate with factory hardware, one of its best features.
Hooker Blackheart shorties connect directly to the factory catalytic converters, unlike long-tube C6 Corvette headers, which necessitate custom cat solutions. All of the essential hardware for the OEM O2 sensor is included as well. As of yet, Blackheart shorties are not approved by the California Air Resources Board (CARB). If you get Blackheart headers placed on your C6 Corvette, it is likely that it will pass emissions. Hooker, on the other hand, advises their use strictly for off-road purposes.
LG 05-13 Corvette Super Pro LS3 Long-Tube Headers
Long-tube headers for the C6 Corvette are becoming increasingly popular, and the LG header kit is a great alternative for those looking for some customization. LG’s Super Pro kit is available in a range of configurations to meet your specific requirements. It’s available with or without enormous 3″ high-flow cats, which are designed to have the least amount of resistance possible. Additionally, you can choose between 1 3/8″ or 1 7/8″ primary runners, which can suit any existing or future upgrades to your C6..
The LG Super Pro kit may be used on both LS2 and LS3 C6 Corvettes, making it a versatile option. The LG kit comes with a 3″ performance X-pipe like some of the other choices on our list. Collectors use a 3″ merging design to maximize their ability to scavenge. Some long-tube C6 heads sacrifice low-end torque for high rpm performance. In order to deliver the finest overall performance, the LG kit did not compromise low-rpm torque.
C6 Corvette Headers Upgrade Summary
Adding performance-enhancing headers to your C6 LS3 Corvette is a big and well-publicized upgrade. The gains in exhaust flow and scavenging over the factory C6 exhaust manifold are substantial, and this translates into higher overall performance. Because C6 Corvette headers have become such a popular aftermarket item, there are a plethora of variants to choose from. The key to success is locating the ideal collection of headers.
The setup of the catalytic converter is a significant aspect. Even though catless C6 headers offer the best performance, there are some drawbacks. Catless headers are only for track use and will fail your C6’s emissions test. Long-tube C6 headers with high-flow cats are your best bet if you want the most improvements while still being road legal.
The LS community’s preferred header is a set of long-tube Corvette headers. It all comes down to the fact that they’re great at scavenging and decreasing back pressure. Long-tube headers offer the best performance in the mid-to-high rpm range, but they are more expensive and more difficult to install. Even though shorty LS3 headers aren’t the ideal option for power improvements, many users prefer them because of their quick installation, compatibility with factory catalytic converters, improved exhaust tone, and lower cost.