A Complete 101 Guide to Motorcycle Exhausts (Purpose, Parts, and Types)

The exhaust system is an essential motorcycle component that improves performance, aesthetics, and the sound of the engine. You can improve engine performance by installing a good-quality exhaust system that directs burnt gases out of the combustion chamber. Read this article to learn about motorcycle exhausts, including their types, parts, and maintenance.

The motorcycle exhaust system ensures a quieter riding experience and improves engine performance. The purposes of a motorcycle exhaust system include the following:

An exhaust system is connected to an engine to remove gases from the combustion chamber. It provides a channel for hazardous gases to travel through and expel at the exhaust. The exhaust pipes are installed to protect your legs from being burned by the heat of the engine.

Motorcycle exhaust pipes are fitted with mufflers/silencers at the end to reduce the noise from the engine. The muffler attached at the end of the exhaust pipes causes the gases to expand that muffle any noise as they are expelled. The linings and perforations in the muffler also help lower the volume of the engine.

Motorcycle exhaust pipes are made of insulating material that keeps heat inside and makes the gases pass through the system quickly. This ensures constant airflow that puts less stress on the engine and improves efficiency.

Modern exhaust pipes are equipped with catalytic converters that convert harmful gases like carbon monoxide into less toxic emissions like carbon dioxide.

The basic function of an exhaust system is to expel all the gases from the engine. These gases are produced by burning an air/fuel mixture in the combustion chamber. Exhaust headers are connected to the engine cylinders and transfer the gases to the exhaust pipes.

There are several sections and parts throughout the exhaust system that perform different functions. The sections in the exhaust pipe causing the gases to expand, sending some of the pressure back to the engine, known as back pressure. The back pressure creates a pressure differential in the engine which improves low-end performance and fuel efficiency. If the exhaust system cannot produce back pressure, it will cause the engine to backfire during deceleration.

A straight or drag exhaust pipe does not allow the gases to expand due to there being no back pressure produced. These drawbacks make motorcycles with drag pipes consume more fuel and reduce idling and low-end performance. However, they can produce better horsepower.

Different types of motorcycle exhausts have unique characteristics and features. Replacing the stock exhaust with an aftermarket version can affect the performance, weight, and sound of the engine.

A straight or drag exhaust pipe is a single extended pipe attached to the engine cylinder to protect the rider and passenger better. It can come in multiple styles and shapes and is usually installed with a baffle. A baffle is a perforated small pipe placed inside the exhaust pipe to control the back pressure and reduce the volume of the exhaust. Some riders love the loud sound created by a drag exhaust pipe without a baffle, but this can reduce back pressure that could damage and reduce engine performance.

Separate dual exhaust pipes are heavier than the single drag pipe and usually installed on powerful, bulky heavyweight motorcycles powered by large-displacement engines, such as touring bikes and cruisers. Separate dual exhaust pipes are usually attached to V-twin engines, allowing them to separate the gases from both cylinders. Keeping the gases from both cylinders separate promotes better airflow and reduces shock.

A two-into-one exhaust system helps improve performance in several ways. Firstly, it is lighter than dual exhaust pipes and two-into-two exhaust pipes. Secondly, the rider can lean the motorcycle when turning a corner without scraping the muffler. A two-into-one exhaust pipe improves a motorcycle’s performance by reducing back pressure.

A four-into-one exhaust pipe has four headers connected to four cylinders on the engine that merge into a single collector and muffler. This exhaust system is not commonly found on modern motorcycles. The four-into-one exhaust pipe was widely used in the 1970s when Japanese four-cylinder motorcycles became popular. This exhaust system is lightweight and greatly reduces the overall weight of the motorcycle. During the 1970s, motorcycles with four-cylinder engines had poor handling due to being fitted with four exhaust pipes. The four-into-two exhaust pipe provided better handling and greater lean angles for motorcycles with four-cylinder engines.

Four-into-two exhaust pipes have four headers connected to the four cylinders that merge into two separate collectors and exhaust pipes. This exhaust system is heavier than the four-into-one exhaust system. However, they are not common and are installed on only a few motorcycles.

A slip-on exhaust is a can-shaped pipe with a muffler attached to the exhaust system. It helps reduce weight, provide a sporty look, and produce a louder exhaust note. Slip-on exhausts are also cheaper and easier to install. However, slip-on exhausts do not increase horsepower and torque.

There are various types of motorcycle exhaust pipes and configurations you can use to replace the stock exhaust system. Replacing the exhaust pipe will alter your motorcycle's look, noise, and performance. There are several factors you should consider before choosing an exhaust pipe for your motorcycle, including:

Exhaust pipes are often classified based on what material they are made from. Titanium and carbon fiber exhausts are the most popular yet expensive exhaust pipes due to their being extremely lightweight, able to withstand high temperatures, and ensuring better engine performance. However, if you are working on a tight budget, aluminum and stainless steel exhaust pipes are the best options.

An exhaust pipe configuration can affect a motorcycle’s performance, weight, and aesthetics. The exhaust configuration best suits your motorcycle depends on the model and engine. For example, a motorcycle powered by a V-Twin engine will perform better if fitted with a two-into-one exhaust system than a two-into-two exhaust system. Removing a muffler reduces the weight of the exhaust system and increases torque. Prioritize exhaust pipes that improve performance and reduce fuel mileage rather than produce a loud noise and improve the look.

Mufflers are available in several designs to satisfy different rider preferences. Some people prefer a carbon fiber slip-on exhaust that gives their motorcycles a sportier look, while others prefer extended mufflers with slash-cut ends, fishtails, and cigar mufflers.

Motorcycle exhaust systems are categorized by their configurations, designs, and materials. Changing the motorcycle exhaust pipes can alter your motorcycle’s weight, noise, and performance. You can determine which exhaust pipes best suit your motorcycle based on the engine and model. Whichever exhaust system you choose to install, make sure it is environmentally friendly, reduces noise, and complies with emission standards.

If you want to customize your motorcycle to improve its comfort, safety, aesthetics, and performance, Viking Bags offers a wide variety of aftermarket motorcycle parts. These include sissy bars, crash bars, fairings, handlebars, seats, and backrests. You can also improve your motorcycle’s storage capacity by installing sissy bar bags, saddlebags, tour packs, and tank bags.