If you’re a big bike owner, then chances are you already have an aftermarket exhaust system fitted onto your bike. If not, you’re likely in the market for one. This isn’t really surprising, as big bikes, with their multi-cylinder engines, sound really good with an aftermarket pipe, especially in comparison to smaller displacement machines. That being said, big bikes still aren’t above the law, and have a few things that need to be considered when changing their exhaust pipes.
On top of that, fitting any old aftermarket system onto your technologically advanced two-wheeler is sure to come with some repercussions, especially if you’re not careful with the exhaust system you’re choosing. Today, let’s take a look at a few things you ought to consider if you’re in the market for a new exhaust system for your big bike.
Make sure it’s not too loud
Of course, the first thing you should take note of is how much louder your bke will be after fitting an aftermarket exhaust pipe. To make it clear, the LTO has stated that 99 decibels will be the limit of the sound of any vehicle’s exhaust. Decibel readings are to be taken at “a 45-degree angle from the exhaust center-line”, and “at a distance of 0.5m from the exhaust outlet.” That said, it’s always best to stay well within the decibel limit to ensure you stay out of trouble, especially in checkpoints, or when renewing your bike’s registration.
In order to do this, you can do some research on the exhaust system you’re eyeing for your motorcycle. Top-shelf brands like Akrapovic, SC Project, or LeoVince—the legitimate ones, not the counterfeit ones you can buy on the side of the road—all have this information posted on their official websites, as well as compatibility with select makes and models. Remember: there’s no such thing as a one-size-fits-all, especially when it comes to genuine, name-brand exhaust systems for performance-oriented machines.
Slip-on or full-system?
The next thing you should consider is the type of exhaust system you ought to purchase. Some bikes, like the Kawasaki Ninja ZX-6R, can be fitted with slip-on systems, as their exhaust systems come in multiple pieces. This means that you can run the stock headers and midpipe with an aftermarket slip-on and muffler. This is a lot cheaper, easier to install, and doesn’t usually require any tuning of the ECU. As such, we’d recommend a slip-on system, so long as it’s compatible and designed specifically for your bike.
On the other hand, bikes like the Yamaha MT-07, whose exhaust systems are one piece from the headers to the tailpipe, have no other choice than to go for a full-system. Now, full-system exhausts tend to be noisier than slip-ons, as they do away with all the stock baffles, catalytic converters, and silencers. However, some premium full-systems do come with removable dB killers and silencers meant to keep the volume down, while enhancing your bike’s sound and engine performance as advertised.
Consider getting an ECU tune
An ECU tune may or may not be necessary depending on your specific motorcycle, as well as the type of exhaust system you choose to install. Some of Akrapovic’s models explicitly state that they work best with an ECU reflash and dyno tune. Meanwhile, other systems will also state that no tuning of the ECU is required whatsoever.
A few telltale signs that your ECU is in need of tuning will be a check engine light, obviously. This means that your new exhaust system has tripped a sensor, and is telling your ECU that your fuelling is out of whack. Generally speaking, a free-flowing exhaust results in your engine running leaner than intended. Another sign that your ECU could be in need of a reflash is backfiring or stuttering upon deceleration. Although it may look cool, spitting flames when closing the throttle could be a sign of detonation—something you’d like to avoid, especially if you’re looking to get the most out of your engine’s service life.
Stay away from fake, "universal" pipes
Yes, you could definitely opt for a universal exhaust system. However, there will surely be drawbacks and ramifications when it comes to your bike’s performance. Plus, even exhaust pipes advertised as universal still need a link pipe or adaptor in order to work properly with a specific make and model. As such, make sure to do your research and get all the parts needed before pulling the trigger on a shiny new exhaust canister. Not all motorcycles have link pipes readily available, and sometimes, you’re going to have to resort to having a link pipe fabricated in a machine shop.
Furthermore, top-of-the-line aftermarket exhaust systems have been engineered specifically for a certain model. This means that the technology placed into a specific exhaust system varies from bike to bike. As much as possible, it’s a good idea to get an exhaust system designed specifically for your bike, in order to avoid issues such as check engine lights, lean running conditions, and exhaust leaks down the road.