Are Downpipes Worth It?

Downpipes are definitely worth it if you also do a dyno tune – it provides a boost in horsepower and makes your car sound more aggressive. However, if tuning is not done, horsepower gains are minimal – making downpipe not worth the money. If instead, all you want is a better sound, then there are many cheaper alternatives. 

Did that answer your question? If not, I understand. There are many factors which could make downpipe worth it or not worth it. Let’s take a look at all of them and then discuss whether downpipes are worth it for each scenario.

If you are looking into downpipes, then I am assuming you already know how turbo works… right? If not, simply put a turbo is an air compressor that sucks air from the surrounding and delivers it to your car’s combustion chamber to create a bigger explosion and more HORSEPOWER. 

The true beauty of a turbo lies in the fact that it’s self-powered by its own turbine. When exhaust gases leave the combustion chamber and flow into the exhaust pipe, the turbine inside a turbo is spooled along the way – producing energy required for the turbo to function. Pretty efficient right?

Here’s an article I wrote comparing turbocharger and supercharger. Which Is Better: Supercharger Or Turbocharger? If you are a little confused, go read up this article and understand how a turbo works first.

Downpipe is a pipe which connects turbo into your car’s exhaust system – allowing the exhaust gases to spool the turbo and then flow back out into the exhaust system where they eventually exit the car. 

Aftermarket downpipes are bigger and wider than stock. This means exhaust gases can flow much easier and spool the turbo even harder – creating more energy for the turbo to suck more air and deliver it to the combustion chamber.

Aftermarket downpipe comes in two types: catted and catless. Catted downpipe means the downpipe equips a catalytic converter, whereas catless downpipe does not. 

If you don’t already know, a catalytic converter (CAT) is responsible for converting toxic exhaust gases into non-toxic ones. Things like carbon monoxide (CO) are converted into carbon dioxide (CO2) – done to keep both you and the environment safe.

Catless downpipe is definitely not worth it. They are indeed cheaper and can provide a little more horsepower. However, the cons far outweigh the pros: failed emissions, terrible exhaust smell, horrible for the environment and switched on check engine light (CEL) 

I cover more about catted downpipe vs catless downpipe in this article. What’s Better: Catted Or Caless Downpipe? 

In this article, I will only be focusing on catted downpipe – because that’s the only version that you should consider.

To understand whether downpipe is worth it or not, it’s important to know the full pros and cons of a downpipe. Let me list all of them here.

Pros of aftermarket downpipe

1. Increased horsepower. Installing a catted downpipe with a tune can give you up to 40 horsepower and probably half that without a tune – about 20 horsepower. This is a pretty good boost of horsepower from just one performance mod.
2. Louder exhaust sound. Aftermarket downpipe is wider and less restrictive than a stock downpipe. This means sound waves can travel better – providing a louder sound when you accelerate. Read my other article if you are interested. Does Downpipe Make A Car Louder? 
3. Works well with other mods. Stock downpipe can be the most restrictive component in your car. Replacing it today will work well in the future when you decide to also change your exhaust pipe and air intake. Combined together they will provide a much better exhaust flow overall. And then bring it to a tune after you have all these parts – performance gain will be awesome.
4. Relatively cheap mod. A good catted downpipe costs about $350. This is a relatively cheap mod, considering how much horsepower it can give. This price tag does not include installation and tuning fee! Will cover more on this at the bottom.
5. No Check Engine Light (CEL) if tuned. If you bring your car for a tune after installing downpipe, then it should not light up CEL. If it does, speak to the tuner – he can help you. If you don’t bring to a tune, there’s a chance that a catted downpipe will not light up the CEL (it most probably will though, but lesser chance than catless downpipe).

Cons Of Aftermarket Downpipe 

1. Have a slightly unpleasant exhaust smell. With downpipe installed, you may have some unpleasant exhaust smell – likely caused by the less restrictive catalytic converter. This smell is not so bad and will only be apparent when you are stopped for a long time – like in a long traffic. You should not be smelling it from inside the car though. 
2. Void warranty on related parts. With an aftermarket mod, you will void your car warranty. But this will only impact related parts like turbo and exhaust systems. Warranty for things like AC and electronics should still apply. Check out Magnuson Moss Warranty act for more info on parts warranty.
3. Not street legal. Aftermarket downpipes are not street legal. But if you get a catted downpipe, then traffic cops would likely not recognize the installation – even if they were to look at it from below. That being said, downpipes are generally for tracking and off-roading use only and not street legal.

A downpipe costs more than just the downpipe. You also need to think about installation and tune. Let’s break it down. 

• Catted downpipe costs about $350
• Installation costs about $200
• Tuning costs about $300

Those total to about $850. I think it’s relatively cheap considering you will get horsepower gain you will get (about 40-50 horsepower), improved exhaust note and tuning.

Installing it yourself is also an option. Though, it could get a bit difficult because there’s not much space to work with. If you are a beginner, I could see it takes about one full day to do. Here’s a YouTube video showing you how to install a downpipe.

If you are installing a downpipe for the horsepower gain, then it’s definitely worth it. Combined with a tune, you could see a major boost in horsepower – about 40 to 50 horsepower gains. 

After installing a downpipe, the exhaust flow in your car will be improved considerably. This works really well if you were to install other mods in the future like exhaust, cold air intake or upgraded turbo.

If you want to install downpipe just for the sake of an improved sound, then it’s not worth it. I recommend you look into other mods if all you look for is an improved sound.

Performance mufflers or axle-back exhaust are good starting points. They both cost much cheaper and will produce better noise. 

If you don’t have the budget but still want an improved sound, then drilling some holes on your exhaust is also an option. This method actually works surprisingly well – you just have to make sure you are drilling the holes at the right location. 

Check out my other article for more info on improving car sound on a budget. 5 Ways To Make Car Louder For Cheap. 

Installing downpipe without a tune is not recommended and not worth it. You will not gain as much horsepower (about 20 horsepower) and you could potentially have wear and tear damages on your exhaust valve.

I cover more about this topic in my article here. Running Downpipe Without A Tune (Should You?) 

Installing downpipe on your car will not void the entire warranty of your car. This is because you are protected by the Magnuson Moss Warranty Act.

The “Magnuson-Moss” act protects you from being denied your warranty just because you have installed an aftermarket part or performed any modification. This act applies to any item costing more $20 or more and is a federal law in the United States – which means it applies to all states.

To void your warranty, a dealer must specifically point out how your aftermarket downpipe is a direct cause to your problems. Even if the dealer is able to point that out, you won’t lose the entire warranty on your car. 

For example, electronic components like AC, wipers and lights would still be covered. You will likely only void the warranty for your turbo and exhaust. 

So with that being said, I think installing a downpipe for a car under warranty is worth it. Especially if it’s already in your intention to install more mods in the future.

With all the explanations done, I recommend you install downpipe only if you are looking for the horsepower gain. And make sure you bring your car to a tune after that. 

If you are trying to save cost, you could install the aftermarket downpipe first (install it yourself if you have to). And then wait until you have also installed cold air intake and catback exhaust before you bring your car for a tune.

When you have installed all those aftermarket components, the airflow on your car will be primed for horsepower gain. Tuning it then will give you a major boost in horsepower.