…If You Buy the Right One
Upgrading a vehicle’s exhaust system is fun. The rumble of an upgraded system is intoxicating, as is the improved throttle response and slightly increased power.
However, before you go out and slap a new muffler or cat-back system on your vehicle, it’s important to think about performance, system size, material, drone, and overall noise levels. Otherwise, you could end up with an exhaust system that you really won’t like.
Do Exhaust Systems Really Improve Performance?
Exhaust systems can improve performance when they’re properly sized and tuned for your specific application. The reason? Most factory exhaust systems are designed to be quiet first and efficient second. This is because the vast majority of new car buyers don’t want to hear a roaring exhaust system. Car manufacturers have learned that it’s better to sacrifice a few horsepower than it is to produce a vehicle with an exhaust system buyers consider to be “too loud.”
Thus, performance enthusiasts who can live with some exhaust noise can add power to most vehicles just by upgrading the factory exhaust. Generally speaking, an upgraded exhaust will increase total horsepower and torque output 1-2%. While this isn’t a tremendous increase, most buyers appreciate the aggressive sound of the system along with improved vehicle throttle response.
When It Comes To Exhaust Pipes, Bigger Is Not Always Better
A common misconception is that larger exhaust pipes are better. This is probably because most people tend to think of an exhaust pipe like they would a drain pipe on a household gutter – if you want the water to drain more quickly, you need a larger drain pipe, right?
The problem with this thinking is that it doesn’t account for heat. Exhaust gases are incredibly hot when they leave the engine. As these gases move down the exhaust system, they become cooler and more dense. If these gases cool too quickly (as they would in an over-sized system), they can become dense enough to restrict exhaust flow.
While there are some comprehensive guides on proper exhaust system sizing (like this one from ExhaustVideos.com), a good rule of thumb is to purchase a tuned exhaust system designed specifically for your vehicle. Don’t let your local muffler shop bolt on whatever they think is best – more likely than not, you’ll end up with an exhaust system that hurts performance rather than helps it.
Exhaust System Noise Violations Are Real
All US states, and nearly all US municipalities regulate vehicle exhaust system noise levels. While these regulations can vary – as can enforcement – there are two good rules of thumb every exhaust system buyer should follow:
- Exhaust systems without a muffler – a.k.a. “straight pipes” – will almost certainly earn you a noise violation ticket at some point, as unmuffled engines are universally illegal.
- The companies that manufacture and sell exhaust systems usually know when their system or muffler is too loud for public streets. To avoid legal problems, these companies will say that these overly loud systems are for “racing” or “off-road” use only. If your system came with one of these disclaimers, it’s probably too loud for street driving.
Noise violation tickets can be quite costly, so it’s best to avoid them and install a system that’s designed for street use.
Drone and Buyer’s Remorse
When we speak with people who are dissatisfied with their exhaust system, it’s almost always because the system makes a loud hum at highway speeds. This hum – known as “drone” – can range in severity from annoying background noise to a loud hum.
The problem with drone is that most aftermarket exhaust systems and mufflers have some sort of drone. Low frequency hum at highway speeds is the nature of performance exhaust design – it’s essentially inescapable. The trick is to minimize this hum, and different manufacturers have different levels of success with that task.
If you want to avoid exhaust system buyer’s remorse:
- Drive a vehicle with the exhaust you want before you buy. That way, you can see if the noise on the highway is livable.
- Remember: The louder the exhaust, the louder the drone.
- Dual exhaust systems are usually worse than single exhausts when it comes to drone. If you’re concerned, you probably want to go with a single exit design.
Finally, it’s important to point out that some vehicle types are more prone to drone than others. Pickup trucks are particularly vulnerable, as most truck mufflers are located under the passenger compartment.
Last, A Word About Materials
Exhaust systems and mufflers are typically offered in the following materials:
- 409 Stainless Steel – The most common option, 409 combines excellent corrosion resistance with affordability.
- 304 Stainless Steel – Known as “marine grade” stainless steel, 304 is even more resistant to corrosion than 409 and looks great when polished. It’s also relatively expensive.
- Aluminized Steel – Not as corrosion resistant as stainless, aluminized steel is the most affordable material available.
For most vehicles, 409 stainless steel is probably the way to go. 409 stainless steel exhaust systems last 8-10 years in most environments, which are why most automakers use this material for the factory exhaust system. Aluminized steel can be an OK choice, but it’s not nearly as durable as stainless steel, and can begin to corrode in as little as two or three years. Therefore, unless you live in a very dry climate, you should only buy aluminized exhaust components for older vehicles that are near the end of their expected life.
Finally, while polished 304 stainless systems are shiny and cool, they’re probably a waste of funds…not many people are going to see the polished pipes under your vehicle.
A Little Homework Goes a Long Way Towards Making the Right Choice
Whatever aftermarket exhaust system you choose, you’ll be wise to take your time and do your research. You can talk to other vehicle owners about their systems online, attend local meet-ups and car shows to see what you can hear, and even watch videos online to figure out what different systems sound like.
When you buy, invest in a good quality material and a tuned system that’s specifically designed for your car. Don’t make the mistake of buying a muffler that’s too loud or rigging together a system that’s too big – all you’ll end up with is reduced performance, drone, and dissatisfaction…and maybe even a ticket for a noise violation.
Finally, when you get the right system, know that it can sometimes take 500 to 1,000 miles for the muffler to “mellow out.” The sound you hear coming out of the tailpipe on day one will probably change in a month or two.
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Ready to bolt on an exhaust kit for your car or motorcycle. Search eBay Motors Parts and Accessories for the correct fitment of your car HERE.
Author Jason Lancaster is the founder of ExhaustVideos.com, a website dedicated to helping consumers choose the right exhaust system before they buy. Jason also works with BlueSpringsFordParts.com, and recommends that every Ford Mustang owner check out the performance exhaust systems offered by Ford Racing before buying anything aftermarket.