If you want to increase the horsepower of your car, straight piping is a popular choice—but it will increase the total horsepower by a relatively small amount, usually about 5 or 10 hp.
Straight pipes increase horsepower by reducing back pressure in the exhaust system, allowing the engine to expel exhaust gases more quickly, increasing power and torque.
However, if you have a turbocharged or supercharged engine, straight pipes can decrease horsepower because these engines rely on back pressure to function properly. If you remove the back pressure, you can reduce the engine's boost, thereby reducing horsepower.
The other option many car enthusiasts choose is to do a muffler delete. The car’s muffler is designed to reduce noise from the engine, but many drivers believe it also reduces power, so they’ll remove it and install a straight pipe exhaust system.
Putting a straight pipe on your vehicle is a bit pricey. Here’s what you can expect:
Straight pipe kit: $500 to $600
Keep in mind that putting a straight pipe on your car generally means removing the catalytic converter. Because the cat is designed to convert harmful vehicle emissions to less harmful compounds, a car without a catalytic converter won’t pass an emissions inspection.