There are multiple ways to make a car backfire with or without modification. Your car will backfire because too much fuel is being put into the motor and leading access fuel to getting into the exhaust heating the fuel to combustion. Most cars from factory will run a little bit rich to prevent motor damage from pre detonation. This means you can stomp on the gas for a split second and while you let off the gas it will backfire. Another way to increase noise and ease of causation is to remove the catalytic converter and remove the factory muffler. In most US states the removal of a catalytic converter is illegal and carries a $10,000 fine. I would not advise anyone to remove a catalytic converter!
Is backfiring good? Short answer is no it will cause poor fuel mileage, loss of power and shorten the life the motor, and if your car is turbocharged backfiring will cause your turbo to prematurely fail.