Motorcycle Exhaust Upgrades: What You Need to Know
One of the most important elements for motorcyclists is the exhaust. Not only does it help give personality to our motorcycle with its unmistakable sound, but it also plays a key role in engine performance. Today we'll go in-depth, talking about how to modify and homologate your exhaust, how to choose the right one for your bike, and more.
What is the Motorcycle Exhaust for and Why Change it?
The motorcycle exhaust is used to expel exhaust gases produced during engine combustion. A good exhaust system allows the engine to "breathe" better, improving performance and fuel efficiency. But what is the purpose of changing the motorcycle exhaust? Changing the exhaust can lead to more power, improve the motorcycle's appearance, and produce a nicer sound.
But beware. Not all changes are allowed by law. Before making any changes, it is important to know how to type-approve the motorcycle exhaust. The motorcycle must undergo a technical inspection to ensure that the exhaust meets safety and noise standards.
Silencer and dB Killer
The silencer (or muffler) and dB killer are two components of a motorcycle exhaust that serve to control and reduce the noise produced by the engine.
The muffler is an integral part of the exhaust system. It is designed to reduce the noise of exhaust gases expelled from the engine through a series of chambers and pipes that bounce the gases around, dissipating their sound energy.
The dB killer, on the other hand, is an add-on, usually a perforated metal tube, that can be inserted or removed from the muffler. Its main purpose is to further reduce noise by lowering the decibels emitted by the exhaust. Although the sound becomes quieter with the dB killer, it can also have a slight effect on the bike's performance, as it slightly restricts the flow of exhaust gases.
But what happens if you remove the dB killer? You will certainly have a "fuller" sound, but beware, you may risk fines. If you are stopped without a dB killer, you risk a fine and suspension of your license, unless the muffler is approved for use without one.
The Modifications to be made to the Exhaust
There are several modifications that motorcyclists often make to their exhaust system to improve its performance. Here are some of the most common ones:
Replacing the muffler: This is the most common modification. Replacing the standard muffler with a sport or high-performance model can increase engine power and performance. These exhausts are designed for optimal exhaust gas flow, allowing the engine to "breathe" better.
Complete Exhaust: Rather than replacing just the muffler, some riders opt for a complete exhaust system, which includes the manifold and exhaust pipes. This can lead to a more significant improvement in performance, but it is also more expensive and complex to install.
Removing the dB Killer: Many exhausts are equipped with a dB killer, a device that reduces noise. However, the dB killer can also restrict exhaust flow, so removing it can slightly improve performance. Keep in mind, however, that in many places removing the dB killer is not legal, because it can cause the allowed noise limit to be exceeded.
Reprogramming the ECU: When modifying the exhaust, it is often also necessary to reprogram the engine's ECU to adapt to the new gas flow conditions. This can optimize engine performance with the new exhaust system.
Always remember that when you make exhaust modifications, you must make sure they comply with local laws.
How much power can I gain?
The amount of power you can gain by modifying your motorcycle's exhaust depends on several factors, including the type of motorcycle, the type of modification and the quality of the exhaust you are installing.
In general, a good aftermarket exhaust system can improve engine performance by allowing exhaust gases to escape more freely, which in turn allows the engine to intake and burn fuel more efficiently. This can lead to an increase in performance that, in some cases, can be up to 5-10% more power.
However, it is important to remember that not all exhaust modifications will lead to an increase in power. Some aftermarket exhausts are designed primarily to improve the sound or appearance of the bike, and may not have much impact on performance.
Also, any exhaust modification should be accompanied by proper tuning of the engine's fuel system, otherwise you may not get the most out of the modifications you have made. One option may be reprogramming the ECU, which can help optimize performance with the new exhaust system.
Increasing the sound of the exhaust
Increasing the sound of the motorcycle can be an attraction for many motorcyclists. This can be accomplished by replacing the exhaust with a sports exhaust or by modifying the silencer or dB killer. Always remember, however, that the sound must not exceed legal limits.
The most common method is to install a free-flowing exhaust.
Free-flowing exhausts, also known as direct exhausts or straight pipes, eliminate noise-reducing components of the exhaust system, such as the muffler. This makes the sound much louder, but in many places it is not allowed, so always check local laws.
Homologation
To check if your exhaust is type-approved, you need to look for the type-approval label or mark on it. This label may have different formats depending on the country, but it usually includes an approval number and sometimes the logo of the certifying body. You can also check the manufacturer's manual or website to find information about the type approval.
If you are stopped and the police find that you are using an unapproved exhaust, the consequences can vary depending on the local law. In many places, you may be fined. In some cases, more severe penalties, such as confiscation of your vehicle or suspension of your license, may also apply.
In addition, if your vehicle causes excessive noise or pollution due to an unapproved exhaust, it may fail the mandatory periodic technical inspection, which could result in repair costs and possible fines.
Therefore, to avoid problems, it is always advisable to make sure that any exhaust modification complies with local laws and regulations. If you are not sure, consult a professional or your local certification body.
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The motorcycle exhaust is a key component to the performance and style of your bike. Whether you want a deeper sound, better performance or just a grittier look, choosing and modifying your exhaust are key steps. But remember, any modification must be done within the law to avoid problems in the future.
