Making More Sixth-Gen Camaro Horsepower With Kooks Long Tube Headers


Over the years, long tube headers have earned a great reputation among enthusiasts for making power. Many enthusiasts refer to them as one of the first bolt-on upgrades to perform on their cars, as long tube headers have been proven to make power and torque while providing that signature musclecar sound every car fan desires.

On the quest for more horsepower and torque, Ryne Cunningham, owner of Cunningham Motorsports (CMS) out of Murrieta, California, enlisted the help of Kooks Headers and Exhaust to provide his recently acquired 2016 Camaro SS with a set of long tube headers and green catalytic converter connection pipes (green cats). Installation took place at Cunningham Motorsports and was performed by CMS technician Mike Franz.

Follow along as we discuss the features and benefits with Kooks, as well as go over the performance aspects with a before and after dyno test and driving impressions.

Cunningham’s Goals

Cunningham's Red Hot sixth-gen Camaro SS pre-installation.

Cunningham’s Red Hot 2016 Camaro SS.

If anyone is looking to modify these vehicles, the long tube headers are a necessity. – Michael Alvarez, Kooks Headers and Exhaust

For the time being, Cunningham’s plan is to maximize the potential of the all-new LT1 engine found in the sixth-gen Camaro platform. With advances in technology such as direct injection and continuously variable valve timing that refines GM’s fifth-generation small-block V8, there’s a whole lot of uncharted territory to be discovered.

The goal for this segment of upgrades to Cunningham’s sixth-gen Camaro is to make as much power as possible with the new Kooks’ long tube headers and green cats combination.

Cunningham acquired his 2016 Camaro SS from Boardwalk Chevrolet in Redwood City, California in December of 2015. The car is finished in GM’s Red Hot exterior color and features an optional eight-speed automatic transmission from the factory which is shared with the C7 Corvette Stingray. This transmission has proved to be a strong option for car owners who are looking to up the power potential in their LT1 powered cars.

Overviewing The Parts

Kooks 2016 Camaro SS 1 7/8-inch Header and Green Catted Connection Pipes Combination

  • 1 7/8 by 3-inch stainless-steel long tube headers
  • 3-inch OEM green-catted connection pipes
  • OEM outlet for use with stock exhaust
  • Factory exhaust requires cutting
  • Kit includes everything necessary for installation
  • Includes Kooks 49-state legal EPA certified ultra high-performance green catalytic converters
  • PN 2260H430
Kooks advised Cunningham to use the company’s 1 7/8 by 3-inch header and green-catted connection pipes combination (PN 2260H430). Michael Alvarez from Kooks explains the features of long tube headers and green cats combination.

“The headers we designed for this vehicle utilize the factory LT1 engine’s cylinder heads to produce the best horsepower and torque gains possible,” Alvarez said. “This system is created from 304 grade stainless-steel which is hand-crafted by our skilled fabricators here in North Carolina. These long tube headers will allow the new LT1 engine to breathe better, and thus perform better.

For those looking to modify their vehicles, the long tube headers are a necessity. When compared to shorty headers, the long tubes are a little bit more money, but they pack a much bigger punch. The only drawback from installing these headers is the increased number of speeding tickets you may get.”

Alvarez also describes the green cats in detail saying, “The green cats are constructed with a stainless-steel core coated with platinum, and the end caps are furnace-brazed to the body. They differ from the OEM cats because the green cats have 300 cells per inch, while the factory cats generally have 500 to 700 cells per inch; thus making the green cats flow much better than the OEM cats.”

The Initial Dyno Test

Cunningham's baseline for its Camaro started at 427.9 horsepower and 428.1 lb-ft of torque at the rear-wheels after an E85 tune.

Baseline for the CMS Camaro measured in at 427.9 horsepower and 428.1 lb-ft of torque at the rear-wheels after an E85 tune.

Prior to installing the new long tube headers and green cats, Cunningham’s Camaro played host to only a custom E85 compatible tune using HP Tuners software performed in-house by Cunningham.

In bone-stock form the Camaro laid down an impressive 394.1 horsepower and 392.6 lb-ft of torque at the rear wheels. Horsepower numbers such as those put this Camaro closer to 464 horsepower at the crank if we were to use the common 15 percent drivetrain loss method of calculation.

After_Dyno1With the addition of a custom 91 octane tune, Cunningham’s Camaro put down a healthy 402.8 horsepower and 401.1 lb-ft of torque at the rear wheels on the shop’s in-house Mustang dyno. While happy with the current tune, CMS decided to push the limits of the Camaro even further by testing E85 fuel. Incorporating a new basic flex fuel sensor, the new tune produced 427.9 horsepower and 428.1 lb-ft of torque at the rear wheels. Those numbers served as the baseline for pre-installation of the Kooks long tube headers and Green CATS.

“No issues running E85,” Cunningham said. “It’s pretty straight-forward, as a lot of newer vehicles are compatible from the factory.” Cunningham says there’s a lot more participation on the tuning side of things when it comes to running E85 properly, but we’ll be covering that in another story at a later date.

Designing And Manufacturing With Kooks

The Green Cats in all of their stainless-steel glory.

The Kooks green cats in all of their stainless-steel glory.

We inquired with Alvarez regarding any challenges the company may have had during the research and development of the sixth-gen Camaro platform. He told us how the process began and what steps were taken to develop the components that are available today.

IMG_5887GR“We started the development of the sixth-gen headers as soon as we found out they were coming equipped with the new LT1 engine,” Alvarez said. “At first, we redesigned our fifth-gen headers to fit the new engine. We soon realized that we had to build a brand new design for this car. Fortunately, we attended a SEMA measuring session for one of the first Camaros offered. After we designed the first set of headers, we learned that the vehicle was manufactured with two different sub-frames. This change from the factory caused us to redesign our headers for the third, and hopefully final time.”

IMG_5916GRAlvarez also gave us a look into the manufacturing process, and how it differs from the fifth-gen Camaro platform. “After we have a new design for our systems, the manufacturing process follows almost the same steps,” he said. “The pipes start off in 20-feet long. They are then cut to whatever size is required. For the sixth-gen Camaro, we had to cut it into eight different pipes.”

He continued, “Once the pipes are cut, they are bent on our CNC mandrels, then go to the production assembly line. At this point of the process, the headers get shaped, formed, welded, and ground by our skilled craftsmen.

After this, the headers go through our quality control department where they are verified to meet Kooks’ standards, they then go to our shipping and receiving department where they clean and package the parts prior to shipping.”

Installing The New Headers And Cats

The starting point, a bone-stock 2016 Camaro SS.

The starting point, a bone-stock 2016 Camaro SS.

Even though the sixth-gen Camaro uses a new platform, installing the Kooks long tube headers and green cats combo was relatively straight-forward for Franz at CMS.


Next Franz lifted the car to examine where he would cut the stock exhaust to install the new green cats. Franz marked and taped the location on the exhaust and got to work disconnecting the factory O2 sensors and the recently installed wideband O2 sensors for the E85 tune.

Franz says, “It’s a pretty standard header install. For the most part, it was a pretty straight forward installation. There’s a couple of extra steps compared to a fifth-gen Camaro. The fifth-gen Camaro is one of the easiest cars to install headers on. It’s probably just a skill level or two higher, and you have to have just a tad more patience with it; because it is a smaller car on a smaller platform, and everything’s a little tighter on there (in reference to the sixth-gen Camaro).”

After setting aside the sensors, Franz then began unbolting the front factory cats from their mounting location at the factory headers. Ensuring everything was unbolted, he used a Sawzall to remove both the driver's side and passenger side factory cat pipes.

After letting the car cool down for about thirty minutes, Franz loaded the CMS ’16 Camaro SS on the shop’s Bendpak XPR-10ALP lift and popped the car’s hood to disconnect the battery and apply a pair of fender covers.

Top Row: Franz then lowered the CMS Camaro to the ground to begin the disassembly in the engine bay. He removed the factory air intake at the factory throttle-body. With the intake out of the way, he began by loosening the driver's side spark plugs. Once removed, Franz moved over to the passenger side header. To gain access to factory passenger side header easier, he unbolted the factory coolant reservoir and set it aside. He also removed the factory dipstick tube assembly. Bottom Row: Jumping back to the driver's side of the exhaust system, Franz disconnected the intermittent steering shaft in order to remove the heat shield on the factory header. He then removed the spark plugs completely to allow him to pull the factory header off of the car along with the gaskets. They followed the same procedure (minus the steering shaft step) to remove the passenger side headers as well.

After removing both headers, Franz lifted the car in the air again and began test-fitting the new Kooks long tube headers by feeding them up and through the bottom of the car. Unfortunately, the passenger side gave us issues, but Franz found a way to make them fit.

“The skid-plate needed to be removed to get the new headers into it (referring to the car) because they’re just too bulky of a piece to get in there, and there’s only 10 or 12 bolts holding it in,” Franz said. “It really opens it up, and if you do that first thing when you get the car up on the rack, it’ll make it really easy.”

Once Franz removed the factory skid-plate, the installation went as smooth as butter. He was able to fit the passenger side header into the engine bay from the bottom with no issues. He then fit the driver's side header and installed the supplied gaskets from Kooks, then tightened down the new header.

Next Franz installed the passenger side gasket and header, and reinstalled the factory air intake, the factory dipstick assembly, and the coolant reservoir he removed earlier. After bolting back on the coil-pack covers and torquing everything to spec; the engine bay was complete.

Top Row: Franz proceeded by lifting the car again to gain access to the bottom portion of the exhaust. He reconnected the front O2 sensor and bolted the new Kooks green cats to the newly installed long tube headers. Some additional cutting was required to the cuts made earlier to ensure the new green cats would bolt up properly with the supplied exhaust clamps from Kooks. Bottom Row: With the new cats and long tubes bolted to the exhaust, Franz finalized the process by reinstalling the wideband O2 sensors and the factory skid-plate, and reconnecting the battery.

Dyno Results And Driving Impressions

After installing the new components, the CMS sixth-gen Camaro roared to life and sounded angry as hell. Even with the factory cat-back in the ‘closed’ position, it was was noticeably louder.

Ryne loaded the Camaro back up on the shop's in-house Mustang dyno and initiated another pull. When all was said and done after some additional tuning, the CMS Camaro laid down a healthy 447.2 horsepower and 453.3 lb-ft of torque at the rear-wheels.

Cunningham loaded the CMS Camaro back up on the shop’s in-house Mustang dyno and initiated another pull. When all was said and done after some additional tuning, the CMS Camaro laid down a healthy 447.2 horsepower and 453.3 lb-ft of torque at the rear-wheels.

Spinning the rollers again at CMS, the post-install dyno numbers came in at a healthy 447.2 horsepower and 453.3 lb-ft of torque at the rear wheels. That’s a gain of 19.3 horsepower and 25.2 lb-ft of torque at the rear wheels. Not bad for a bolt-on upgrade and some re-tuning. If we examine the dyno graph, we’ll see that the new-found power from the long tube headers and green cats is an immediate gain in terms of horsepower, and torque is present throughout the curve.

How does this power translate to the driving experience? Cunningham said, “Mid-range torque has improved vastly. Kooks’ long tube headers and higher-flowing green cats makes the car sound much throatier, and more raspy, but in a good way. Torque in general has definitely improved; especially throughout the lower end of the RPM range, but overall throughout the power band as well.”

After_Dyno2We asked Cunningham if the E85 tune made a bigger impact in his Camaro’s new-found power, to which he replied, “It would probably be the same no matter what fuel type we used. The E85 just has a higher starting point (in terms of power). E85 would really shine with forced induction down the road with a new fuel system. The gains our sixth-gen Camaro made are right on par with a C7 Stingray Corvette, which uses the same 6.2-liter LT1 engine.”


The all-new sixth-gen Camaro definitely has a curvaceous silhouette.

The all-new sixth-gen Camaro definitely has a curvaceous silhouette.

Cunningham said there are big plans for their 2016 Camaro SS. While it’s obvious that the new Kooks long tube headers and green cats make respectable gains on a naturally-aspirated car with a tune, he says where they hope to see these components really shine is when a ProCharger system is installed.

These long tube headers will allow the new LT1 engine to breathe better and thus perform better. – Michael Alvarez, Kooks Headers and Exhaust

Alvarez said an upgrade to Kook’s 2-inch primary long tube headers is not needed anytime soon. “We recommend using the 1 7/8th long tube headers when building a vehicle with 700 horsepower or less. For applications over 700 horsepower, we recommend using our 2-inch by 3-inch headers. If someone is building a motor to use a power adder, we also recommend using the 2-inch by 3-inch headers.”

“These catalytic converters have an EPA certification and a proven track record, with a 90 percent success rate of keeping the check engine light off,” Alvarez said. “They were designed to handle high horsepower and high heat applications, and work great on boosted applications where boost numbers can exceed 15 to 20 pounds.”

Keep an eye out for an inside look on sixth-gen Camaro performance as we follow Cunningham Motorsports and the build of this 2016 Camaro SS.

Keep an eye out for updates to the CMS sixth-gen Camaro in the future.

Keep an eye out for future updates about the CMS sixth-gen Camaro.

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About the author

Harrison Noble

Living in San Diego for most of his life, Harrison was exposed to a variety of cars at an early age. His passion for anything that is fast, or has a V8, brought him to Power Automedia.
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