Downpipe and Straight Pipe

What’s the Difference Between a Downpipe and a Straight Pipe?

Tweaking your exhaust system is a common hobby for most gearheads. After all, you can improve fuel efficiency, alter noise, and your vehicle’s aesthetic all with the exhaust system. There are so many different components to the exhaust system that there are a plethora of aftermarket, improvement opportunities.

A frequent exhaust system upgrade includes the exhaust piping. Whether you’re adding exhaust headers or altering to a dual exhaust system, there’s a lot you can do behind the exhaust manifold. One aspect of this is determining if you want a straight pipe or a downpipe.

Straight Pipe vs. Downpipe 

A straight pipe is an exhaust system without a catalytic converter or muffler. It gets its name because it’s essentially a “straight shot” from the exhaust manifold to the back of the vehicle. However, a downpipe connects the exhaust port (the opening where exhaust steam escapes) to the exhaust system’s start. It’s essentially a section of tubing with catalytic converters to clean the gasses produced.

Is Downpipe the Same as Straight Pipe?

No, a downpipe isn’t the same as a straight pipe. In short, a straight pipe produces a lot of gasses whereas a downpipe reduces harmful gas emissions. Without a catalytic converter, straight pipes don’t have a component to change gasses from dangerous to safe. Plus, a muffler can help in the exhaust system process. A straight pipe lacks both these exhaust components, so gasses go right from the manifold into the environment. As you can imagine, this is not safe, and in some states, it won’t pass environmental regulations.

What’s the Purpose of a Straight Pipe?

If a straight pipe isn’t the fastest vehicle feature, what’s the point of having one? That’s easy: straight pipes contribute to more power and produce a loud sound. Most drivers aren’t concerned about sound, but that doesn’t apply to gearheads. Gearheads will add exhaust tips, exhaust cutouts, or remove their muffler, all for the purpose of getting a racecar-like roar with their vehicle. Additionally, you’ll find increased performance, because the exhaust system doesn’t have to work hard to convert gasses and reduce noise.

Does Downpipe Increase Horsepower?

If built right, a downpipe will increase horsepower compared to the stock factory exhaust. Its main purpose is to reduce exhaust gas temperature by directing shot gasses better. Downpipes are made of either stainless steel or carbon fiber alloy, which are materials to better withstand heat than a standard exhaust system.

You can either have a catless or high-flow catted downpipe system. The only difference between the two is that the catless doesn’t have a catalytic converter (hence the name “cat-less”). High-flow catted has an external catalytic converter.

Does Downpipe Increase Sound?

The downpipe system itself does not increase sound. There isn’t a noticeable decibel difference when you add a downpipe, unlike the straight pipe. Of course, you can still do other alterations to change your vehicle’s sound. But the downpipe’s purpose is not to increase sound. 

Is Straight Piping Better?

A straight pipe system is more affordable than a downpipe system. You can spend between $1000 to $1500 for a straight pipe and $2000 to $2500 for a downpipe. Nevertheless, it can be tough for any gearhead to decide which system is better for them. It depends on what you’re looking for as a driver.

If you want increased sound and better performance, the straight pipe might be for you. But, you need to be aware of its harm to the environment and how it might not be legal in your area. On the other hand, if you want to make your car safer and help the engine stay cooler, a downpipe could be wise. Aftermarket questions like this are best saved for the professionals, and that’s where Performance Muffler would be happy to help you.

Let Us Transform Your Vehicle – Contact Us for a Free Quote

Contact Performance Muffler for a free quote. We’re your go-to garage for exhaust work and repairs. And we’ve been proud to call ourselves a top custom exhaust shop in the Phoenix area since 2007.

Feel free to learn more about Performance Muffler and the services we offer. Or, read our blog for additional automotive insight. We cover everything from how long do exhaust systems last to practical guides to jump-start a car.

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