Buy a exhaust with a larger circumference, the larger the circumference, the louder the noise.
The most common way that people make their Harley exhaust louder is to knock a hole in the exhaust baffles. To do this insert an iron bar into the exhaust pipe and then hit it several times with a large hammer.
cut the exhaust at the exhaust manifold and redirect the pipe through your airconditioning system all the way to the driverside airconditioning vent. It should work beautifully.
Heating up an exhaust system and then quickly adding cold water can cause the metal to contract rapidly, potentially leading to cracks or damage. It may also create a loud noise in the moment, but it's not a safe or recommended way to make an exhaust system louder. Instead, consider installing a performance exhaust system designed for better sound.
if possible take the baffles out of the pipe but just don't run a straight pipe that is not good for your Exhaust Valves
get heavier gauge strings, than you can make it sound much louder
Tie it up with coat hangers.
Only if you mean "the power to annoy people". Certain performance enhancements might cause the pickup to be louder, but deliberately going out of your way to make it louder will not automatically make it more powerful.
Well first the two words "performance" and "louder" do not go together. If you make it louder the way you are asking for directions i.e. by removing the baffles. You will lose around 40% - 50% of your performance or power. These bikes rely on compression of the exhaust gasses for about half of the h.p. Try removing the muffler completely and see how it performs, and as per the owner's manual modifying the muffler or running without one, will void your warranty.
Free flowing exhaust, nitrous
easiest way would be and exhaust and air box lid. The TRX's are way to restricted. If you get an exhaust make sure u have the jets adjusted
The loudest exhaust tip is the megaphone style. Though not commonly seen today because of styling changes and they are not in vogue anymore, they can dramatically make certain exhaust louder. They work the same way a musical instrument, (trumpet, tuba, trombone) work. Ever seen a cheerleader use a megaphone? They work off the same principal. Taking the wave length (sound) and tuning it to a amplified level. This may be a oversimplified way of explaining but choose wisely of which you use. Each size and construction can change the sound wave length as well as the structure of the exhaust leading up to it.
easiest way is to slap on a set of cheap headers and dual exhaust pipes