The purpose of a stock exhaust system is to filter the exhaust gas before it enters the environment. All while muffling as much sound as possible. 

The downside to factory exhaust kits is they restrict exhaust airflow. This causes less back pressure that lowers engine performance.

Aftermarket performance exhaust systems solve all the problems of a stock exhaust. 

These exhaust kits have a larger diameter tube, unique bends and other features. These unique features increase both horsepower and fuel efficiency.

In This Article

To understand how a performance exhaust system works. You first need to know how internal combustion engines in cars and trucks work.

  • Fuel & Oxygen Get Sucked Into The Engine Cylinders
  • Fuel & Oxygen Mixture Gets Ignited By A Spark Plug
  • Spark Causes Little Explosions Known As Combustion Which Power Your Engine
  • Combustion Leaves Behind Waste Gases That Choke Out The Engine
  • Exhaust System Purges & Filters The Bad Gases
Combustion engine process TrucksResource Performance Exhaust Systems

The waste gas gets pushed out of the engine cylinders by the pistons to the exhaust manifolds.

Exhaust headers bolt on the engine head with steel tubing attached to each cylinder. 

This tube is a collector, it collects the gas from every cylinder combining it into a single pipe. 

The exhaust gas is then sent down a straight pipe to the catalytic converter.

Performance exhaust manifolds have better design and construction. They expel exhaust gases better than bulky stock exhaust headers.

Incomplete engine combustion results in pollutants. Such as carbon monoxide, nitrogen oxide and other deadly hydrocarbons. 

The catalytic converter is the solution to reduce harmful engine gas emissions.

Catalytic converters have palladium and platinum-coated ceramic beads inside. These beads act as a catalyst. 

When the harmful greenhouse gases enter the cat converter. A chemical reaction occurs with the end result being oxygen, nitrogen, carbon dioxide and water vapour.

Catalytic converters significantly reduce the spread of harmful exhaust gases into the atmosphere. 

The catalytic converter in your vehicle is a law need due to emission standards.

Detects O₂ levels in the exhaust gases. It’s used by the engine control unit (ECU) for fuel metering.

If a car’s exhaust system ended at the catalytic converter. It would be insanely loud and everybody would hate you. 

The purpose of a muffler is to reduce the audio level to a sound we can all appreciate.

Most mufflers use a sound resonating chamber. This chamber uses an equal sound wave to cancel out other sound waves. 

Performance muffler resonating chambers get designed to amplify and tune. Resulting in the exhaust sound being an aggressive, deep growl.

Exhaust gas spins a turbine that powers an air compressor

This sends a high-pressure airflow to the engine that gives a boost in performance.

The last piece of an exhaust assembly is the tailpipe and exhaust tip. Even being so far from the engine, tailpipes give a final pressure reduction for better airflow.

Instead of an unappealing straight tailpipe poking out the back of your car. Tailpipes get fitted with a polished, eye-catching exhaust tip.

Upgrading your truck with a high-performance exhaust system. Provides benefits to both cosmetic appeal and engine performance.

  • Improved Exhaust Sound – performance exhaust systems provide a powerful, rumbling growl sound
  • Increase Fuel Economyhigh-performance exhaust systems maintain optimal air levels in the engine compartment. This results in more efficient combustion that uses less fuel. About a 2% improvement in gas consumption seems average for most truck enthusiasts.
  • More Horsepower – performance exhaust systems flush the exhaust gases better than stock exhausts. Less waste gas and more oxygen allow the engine to breathe better drawing in more air. This results in an increase in the power output of the engine.
  • Cooler Aesthetic – top tier exhaust kits provide an enjoyable sound with an attractive high-class look.

When choosing a new aftermarket exhaust system there are three main options. 

The three most common types of vehicle exhaust systems are cat-back, axle-back and header-back.

Cat-back exhaust kits swap the current exhaust components from the catalytic converter to the muffler. 

They are also known as a diesel particulate filter (DPF) system. These exhaust systems include a new muffler and tailpipe

Depending on the truck you drive they may include a mid-pipe.

Diesel particulate filter systems are among the most popular exhaust upgrades. 

That’s because of the many benefits they provide at a low cost.

Benefits of Cat-Back Exhaust Systems

  • Low-Cost Performance Boost
  • Improve Fuel Economy
  • Tough Growl Sound
  • Emissions Legal

Axle-back exhaust systems replace everything from the rear axle to the exhaust tip

These are easier to install and a lower price than cat-back exhausts. But, they don’t give as much boost to performance.

Header-back exhaust systems swap everything from the manifold to the tailpipes and mufflers. 

These systems allow for custom builds and larger pipe diameters. That allows the exhaust to flow better. 

Manifold-back exhaust systems give the biggest improvement boost to your truck. But, they cost more and harder to install.

Cars with single exhaust systems are the most common. A single exhaust includes one complete exhaust kit with a muffler and exhaust tip

Aftermarket single exhaust systems offer advantages over stock exhaust kits. This is due to the larger diameter pipes and less restrictive bends.

Dual High-Performance Exhaust Systems

Dual exhaust systems are becoming more popular. 

They have two separate exhaust pipes which include. Two catalytic converters, two separate mufflers and exhaust tips.

The dual exhaust system offers a distinctive growl and high-flow capabilities.

A disadvantage to some dual exhaust systems. The potential for a pressure imbalance between the two pipes. 

To solve this issue dual crossover exhaust systems got created. These incorporate a special crossover pipe. 

This pipe allows exhaust gases to flow between each pipe balancing themselves out.

Performance Exhaust Material & Construction Benefits

High-performance exhausts get manufactured from rust-resistant, durable steel. 

There are three main grades of steel for exhaust systems: Aluminized steel, 409-L stainless steel and 304 stainless steel.

  • Aluminized steel exhausts are heavy-duty steel pipes coated in an aluminum-silicon alloy. This material is durable and has great rust-resistance at a low cost.
  • 409-L Stainless steel exhaust systems are very high-strength, rust-resistant and long-lasting at a reasonable cost.
  • 304 Stainless steel exhaust systems are the highest quality and the most durable. 304 Stainless steel has high amounts of nickel and chromium. These metals provide the greatest amount of rust and corrosion resistance.

Stock exhaust pipes get bent using a method called “Crush Bending”. 

This method of pipe bending leaves ridges that prevent a smooth flow of exhaust gases.

Aftermarket exhaust systems use the mandrel pipe bending technique. 

This method allows for a smoother flow of exhaust gases. Which in turn allows for a bigger horsepower increase.

While straight piping or removing your exhaust from the cat back can improve the sound of your truck. 

Removing your exhaust system takes away all the back pressure the gases provide. 

Not only does this decrease engine performance. It releases pollutants into the atmosphere which is illegal.

Performance exhaust systems keep the back pressure high. This stops any gas sucking into the fire chamber as the engine valves change positions. 

Since performance exhaust systems better use exhaust gases. They increase engine performance and total horsepower.

MagnaFlow – A top aftermarket exhaust brand with proven dyno tested products. Magnaflow sells 100% stainless steel exhaust kits that include a lifetime warranty.

Flowmaster – Top aftermarket exhaust system with the distinct “Flowmaster Sound”. They have exhaust kits and accessories of all varieties for cars, pickup trucks, diesel trucks and SUVs.

Cherry Bomb – The glasspack muffler is one of the most popular aftermarket options available. The glasspack comes in various forms that provides excellent sound reduction.

Yes, performance exhaust systems do increase horsepower. Dyno tests and user reports an average increase of 5 to 15 total horsepower.

Aftermarket performance exhaust kits improve engine efficiency by roughly 2 to 10%. Due to improved efficiency, less gas gets used which improves fuel economy.

Performance truck, car and SUV exhaust systems are road legal. The law for motor vehicle exhaust systems states. A vehicle must have a working muffler. One that prevents excessive noise and includes a working catalytic converter.

The majority of aftermarket high-performance exhaust systems range in price from $300 to $1500 for a complete kit.

Yes, you should tune your diesel engine after upgrading to an aftermarket exhaust kit. 

It’s best practice for ensuring everything is working efficiently and you’re getting the most out of your diesel truck.

Yes, upgrading to a cold air intake and high performance exhaust system are two of the easiest ways to add engine horsepower. 

For more information check out aftermarket cold air intakes