Project Murderado: Unleashing The Beast With A Flowmaster Exhaust

project murderado2

When you are going through the list of all the aftermarket exhaust companies and sorting through prices, features, materials, and even where the product is made, it can be exhausting. Bad puns aside, there really are a lot of considerations to take in before making your purchase.

The easy route is to look to companies that have been building quality products in the United States for longer than most of our prized project vehicles. That’s what made us think of Flowmaster.


Behind The Name

For over thirty years, Flowmaster has been pushing the boundaries of muffler and exhaust products. It was a company that was born out of a necessity, as race tracks in California were battling sound issues from racecars being too loud. Many of the racetracks were very close to residential areas and the noise was a problem.

The idea was to reduce the noise without reducing performance. Automotive exhaust science and technology advanced and problems were solved.

Flowmaster custom bends exhaust systems for the best look and fitment, rather than copy the ‘clumsy’ OEM exhaust systems like other companies do. – Dale Dotson, VP of Marketing

When it came time to boost the performance and sounds of Project Murderado, our 2013 Chevy Silverado, we wanted a sound that would match the name. The 5.3-liter Vortec V8 in our Silverado is a solid motor and really wakes up with the increased exhaust gas flow.

To keep everything above board and emissions-legal, a system behind the catalytic converter (known as a Cat-Back) was chosen. To ensure longevity, we wanted a stainless steel system, and since Project Murderado is all about making a statement, we also wanted an aggressive exhaust tone. Flowmaster had just the right kit for our needs with a dual tailpipe Cat-Back system made from three-inch diameter 409S stainless steel with dual four-inch black ceramic tips (PN 817688). Specifically designed for crew and double cab installations, the kit comes backed with Flowmaster’s Lifetime Warranty.

To better explain how Flowmaster develops their exhaust systems, we spent some time chatting with Dale Dotson, Flowmaster’s Vice President of Marketing. “At the development stage of designing exhaust systems, Flowmaster begins with getting baseline horsepower and torque numbers of the OEM exhaust by running the vehicle on our SuperFlow chassis dyno,” Dotson explained. “The factory exhaust system is then removed and the whole fabrication process begins. A lot of factors are taken into consideration when designing a custom Flowmaster exhaust system for a vehicle, such as: the number of catalytic converters and resonators on the vehicle, engine size, the size and volume of the interior (cab area) of the vehicle, and input received from consumers via our customer service department, forums, social media, and more.”

Flowmaster products are made in the USA to keep a tight hold on quality.

Flowmaster products are made in the USA to keep a tight hold on quality.

Dotson went on further, “The R&D project manager takes all the information and then decides on which muffler to select as a starting point to meet the goals of the project. In this case, kit #817688 is an Outlaw system, so we would start by selecting an aggressive muffler, the Super 10 series muffler. Next would be deciding the tailpipe exit location, which the majority of truck owners prefer a ‘dual exhaust’ look.

The fabrication process begins based on all the previous criteria, along with accounting for clearance around spare tires, rear differential, fuel and brake lines, tailpipe exit locations, and the style of tips that work with the design of the vehicle. Flowmaster custom bends exhaust systems for the best look and fitment, rather than copy the ‘clumsy’ OEM exhaust systems like other companies do. The systems are tucked up higher for more clearance and the tailpipes are located with a look that they should have left the factory with, rather than with tips hanging down or exiting at weird angles that just look awkward.”

The kit offers both side exit and rear exit.

The Flowmaster team then test drives the vehicle and puts it back on the SuperFlow dyno to see where the numbers landed. If the exhaust tone and performance gains are not satisfactory, the team dives right back in to make changes or even develop new components to meet the necessary criteria.

Flowmaster offers four different sound levels of exhaust systems. The loudest option, like what we’ve chosen for Project Murderado, is the “Outlaw” system. Next is the “American Thunder” system, the “dBX” system and the quietest option, the “Force II” exhaust system. “Flowmaster’s ‘Outlaw’ exhaust systems are the most aggressive sounding systems we currently offer,” Dotson points out. “They have a deep aggressive tone, both inside the cab area of the vehicle and outside the vehicle.”


Getting Our Truck To Sound Right

Flowmaster builds all of its components to be as easy as possible to install. The state-of-the-art mandrel bent production helps make sure every part is built correctly and fits together just as it should. The first step is to get the vehicle elevated. Using a hoist certainly makes life easier, but is not a requirement. Always make sure your vehicle is properly supported before beginning work.

The stock exhaust system nearly always looks to be an afterthought. No real care is given from the factory to make the components look cool or stylistic.

Out with the old. Cut the tailpipe from the back of the muffler to make removal much easier.

Out with the old! We cut the tailpipe from the back of the muffler to make removal much easier.

The rubber isolators get reused with the new system. A pry bar and lubricant makes removal easy.

The rubber isolators were reused with the new system. A pry bar and lubricant made removal easy.

We unbolted the ball clamp in front of the muffler and then removed it. We used the ball clamp and hardware to be reused with the new inlet pipe.

We bolted in the new inlet pipe using the original ball clamp hardware and also set up the new hanger mounts provided by Flowmaster. We kept all of the hardware snug but still able to wiggle for final adjustments later.

In with the new. When installing each of the parts, snug the hardware but do not tighten completely. At the end, you'll likely need to adjust the pipes for proper alignment.

In with the new! When installing each of the parts, we snugged the hardware but did not tighten completely. This was so we could adjust the pipes for proper alignment later on.

New hangers are provided for the rear sections of the system. The new brackets bolt in using existing holes in the frame.

New hangers were provided for the rear sections of the system. The new brackets bolted in using existing holes in the frame.


Because the Flowmaster system was designed for better aesthetics than a factory system, new hangers were included for the change in pipe position. The new hanger mounts fitted into stock openings in the frame and bolted in.

Left: The rear exit pipes had a slight jog in them to position the tip closer to the corner. Right: The side exit pipes are mandrel bent to pull the tip out under the rear corner of the truck.

Once all the pieces are fitted and adjusted, tighten all the clams down.

Once all the pieces were fitted and adjusted, we tightened all the clamps down.

Flowmaster’s system can be had with either side exit or rear exit. The rear sections of the tailpipes differ to allow for the exit point you desire. The driver side utilizes a mid-pipe, allowing the system to have an easier install around the differential and spare tire.


Feeling The Rumble In Your Seat

The fun part of any exhaust install is when it comes time to fire the vehicle up for the first time to hear the new sound. The Outlaw series exhaust that was installed on Project Murderado was something that we knew would give us a deeper roar.

When on the dyno, the factory exhaust could hardly be heard over the whizzing of the dyno drums, but after the Flowmaster system was installed, the real power of the Chevy V8 can be heard, loud and clear.

Compared to a 2008 Silverado with the same motor with a factory exhaust, our 2012 Silverado made

Compared to a 2008 Silverado with the same motor and factory exhaust, our 2013 Silverado made 8.2 horsepower and 21.8 lb-ft of torque more when looking at the peak numbers.

Taking the truck to the street, we could really tell the difference in the sound of the truck. We had the aggressive sound that we wanted and to our surprise, it did not give us much of a drone inside the cab. This is definitely something that your neighbors will know has changed on your vehicle.

Flowmaster prides itself on exceptional quality and performance for every vehicle they put their hands on. To learn more about Flowmaster, check out their website.


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About the author

Jake Headlee

Jake's passion started at a young age wrenching on cars with his Dad. Obtaining that glorious driver's license sparked his obsession with grease and horsepower, and the rest is history. Soon, he was a general mechanic and suspension specialist, and currently designs and modifies products for the off-road industry. Jake enjoys rock crawling, desert racing and trail running, and writing in his spare time.
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