What is the difference between a downpipe and a straight pipe?

Tuning your exhaust system is a common hobby for most gearboxes. After all, you can improve fuel efficiency, change the noise and appearance of your car with an exhaust system. There are so many different components in an exhaust system that there are many opportunities for aftermarket service and improvement.

Frequent exhaust system upgrades include an exhaust pipe. Whether you're adding exhaust manifolds or swapping out a dual exhaust system, there's a lot you can do behind the exhaust manifold. One aspect of this is determining whether you want a straight pipe or downpipe.

Straight pipe vs downpipe 

A straight pipe is an exhaust system without a catalytic converter or muffler. It gets its name because it is essentially a "straight shot" from the exhaust manifold into the back of the car. However, the downpipe connects the outlet (the hole through which the exhaust vapor escapes) to the start of the exhaust system. In fact, this is a part of a pipe with catalytic converters for cleaning the resulting gases.

Is a downpipe the same as a straight pipe?

No, a downpipe is not the same as a straight pipe. In short, a straight pipe produces a lot of gases, while a downpipe reduces emissions of harmful gases. Without a catalytic converter, there is no component in straight pipes to change gases from hazardous to non-hazardous. In addition, a muffler can help in the exhaust system process. In a straight pipe, both of these exhaust components are absent, so the gases enter the environment directly from the manifold. As you can imagine, this is not safe, and in some states it does not comply with environmental regulations.

What is the purpose of a straight pipe?

If a straight pipe isn't the fastest feature of a car, what's the point of it? It's simple: straight pipes produce more power and louder sound. Most drivers are not bothered by sound, but this is not the case with gearboxes. Reducers will add exhaust tips, tailpipe cutouts, or remove a muffler, all to make their car roar like a race car. Plus, you'll find increased performance because the exhaust system doesn't have to work as hard to convert gases and reduce noise.

Downpipe increases power?

When built properly, a downpipe will increase horsepower over a stock factory exhaust. Its main purpose is to reduce the temperature of the exhaust gases by better guiding the flue gases. Downpipes are made of stainless steel or carbon fiber alloy, which resist heat better than a standard exhaust system.

You may have a reel or high capacity gutter system. The only difference between the two is that the coilless doesn't have a catalytic converter (hence the name "cat-less"). The high flow catheter has an external catheter.

Does the downpipe increase the sound?

By itself, the downpipe system does not increase the sound. There is no noticeable difference in decibels when adding a downpipe, unlike a straight pipe. Of course, you can still make other changes to change the sound of your car. But the purpose of a downpipe is not to amplify the sound. 

Are straight pipes better?

A straight pipe system is more affordable than a downpipe system. You can spend $1000 to $1500 for a straight pipe and $2000 to $2500 for a downpipe. However, it can be difficult for any gearbox to decide which system is best for them. It depends on what you are looking for as a driver.

If you're looking for improved sound and better performance, a straight trumpet might be the way to go. But you should be aware of its environmental impact and that it may be illegal in your area. On the other hand, if you want to make your car safer and help your engine stay cooler, a downpipe might be a wise choice. Aftermarket issues like this are best left to the professionals, and Performance Muffler is happy to help you with that.

Let us transform your car - contact us for a free quote

Contact Performance Muffler for a free quote. We are ready to help you with the repair of the exhaust system. And since 2007, we've been proud to call ourselves the best exhaust system shop in Phoenix.

Feel free to learn more about Performance Muffler and the services we offer. Or read our blog for more automotive information. We cover everything from how long exhaust systems last to how-to guides for starting a car.