The number of aftermarket exhausts are endless. they all make claims of better performance,style and sound. Recently I have been looking at a new aftermarket exhaust for my bike and I'm looking at a M4. These exhausts can have a significant effect on performance and the ability to carry a passenger.
First, the performance. Some bikers go the way of bolting a big bore no-name can on their bikes with the thought of cheap horsepower. Too bad--this rarely happens.
Modern bikes are finely tuned machines. The exhaust plays a crucial role in this system. No-name exhausts typically are not correctly tuned for your application and can actually hurt horsepower and torque.
The best way to evaluate an exhaust's performance is to look at a dyno sheet. So be sure to ask for a dyno sheet for the M4 exhaust. Dyno sheets are available by most high end manufacturers, and they clearly show where and how the horsepower and torque are changed with the new pipe.
The exhaust is specifically tied to your carb/fuel injection. When you change your exhaust it is critical that you have your carb re-jetted or your fuel injection recalibrated. This should be inexpensive at the shop doing the pipe swap.
Passenger Considerations with the M4 Motorcycle Exhaust: The other thing to consider with an aftermarket exhaust is how it will affect your passenger footpegs. Depending on how the system mounts, it might require you removing the rear pegs. This might not bother you, but it is something to consider.
