Full Exhaust Systems

Everything you need to know about Aftermarket Exhausts

Road-legal motorcycle exhausts are complex pieces of kit thanks to stringent environmental regulations. It’s a tall order to juggle acceptable sound levels with emissions laws while at the same time making them cost-effective. As a result, new motorcycle exhaust systems have multiple boxes to tick. Many motorcycle manufacturers have departments of designers and engineers whose sole job is to create the perfect exhaust. As a result, aftermarket manufacturers are investing even more time and money to create better exhaust systems. This fact is a strong indication of the popularity of replacement systems. The fundamental physics behind the internal combustion engine has not changed for the last century. However, the methods of sucking air and gasoline in and forcing exhaust gasses out have altered dramatically. While strict governed amounts of fuel are injected into the combustion chamber, computer-controlled sensors and catalytic converters monitor the flow of exhaust gasses. As a result, modern motorcycle exhaust systems are complex.

Back Pressure

To operate proficiently, exhaust systems need the correct back pressure levels. Back pressure helps regulate the flow of exiting exhaust fumes. Too much from an overly restrictive aftermarket exhaust system will interrupt the flow of gasses. An un-baffled silencer may sound good but this can create too little back pressure that will also adversely affect the combustion process. These scenarios are something to be aware of if you have ever wondered why some exhaust systems and silencers have such a low price point on certain e-commerce or online auction sites. In which case you need to apply commonsense and ask “is an Akrapovic, Yoshimura, Vance or Hines silencer costing 35 Euros counterfeit?” Shopping online with a site you can trust, such as XLMOTO, is the safest way to buy genuine exhaust systems and parts.

Weight Issues

There are many reasons for replacing a stock exhaust or system. Close to the top of this list is weight-saving. For example, Yamaha's FJR1300 sports tourer has a 4-2 exhaust system. Replace the silencers and it will save around 4-kg of sprung weight. Typical weight-saving will be around 50%, depending on the material, whether it's a slip-on silencer or a full system.

Ground Clearance

Replacement exhausts often fit closer to the motorcycle. Being able to lean further into bends before the sparks start flying is another positive spin-off of an aftermarket exhaust. Even the shape can make a difference. For instance, a triangular profile silencer will provide a couple more degrees of lean compared to a round profile stock silencer.

Catalytic Converters and Sensors

When buying any aftermarket motorcycle exhaust, ensure it has the correct features. These extras may include lambda sensor lugs and catalytic converters, if applicable. If, however, either oxygen level sensors or catalysts are required but not present, it could have a dramatic effect on the running of your engine. This consideration is not something you need to concern yourself with any of XLMOTO's replacement motorcycle exhausts. All parts are genuine replacements.

Performance

Whether you experience the difference or not, reducing sprung weight and adding ground clearance can enhance a motorcycle's handling. However, most riders want to know, will an aftermarket exhaust give me a performance gain? Enhanced acceleration and torque will differ from make to make. In terms of performance, a top-shelf full exhaust system fitted to a Yamaha R1 will add another 7-KWh of power and additional torque of almost 10-Nm. Compare these figures to fitting a titanium silencer only and you can expect just over 1-KWh of extra power and torque increase of a little less than 1-Nm. The differences are sizeable and prove two things. First, it's easy to see the importance of a full exhaust system with tuned header pipes. Second, replacing the silencer alone is more about sound and looks.