Table of contents
Introduction
Imagine you’re walking along the sidewalk of the city when you hear the roaring echo of a modified exhaust. I’m not talking about some cheap hack job at a shady shop, I’m talking a real exhaust system. One where the materials are high quality, the welds are flawless, and the system is perfectly tuned to provide a pure automotive symphony. Regardless of what engine comes to your mind, you know exactly what I am talking about. For me, I have a distinct memory of hearing a beautiful exhaust note from an Acura NSX. The owner had an exhaust shop custom build a cat-back exhaust it was insane.
Modified exhausts are a staple in the automotive community. For some, its the first modification they do on their newly planned build. Whether its a muffler delete or a complete exhaust system upgrade, a modified exhaust is a great mod for a car. Modified exhausts provide both a performance benefit as well as a boost to driver experience. Overall, its one of my favorite mods for a car.
Why Install A Modified Exhaust?
As stated before, modified exhaust systems provide an auditory and performance boost. When manufacturers build their cars, there are noise and emissions standards that need to be met. Stock exhaust piping is restrictive and restricts flow. Also, the mufflers and resonators used by OEM exhaust systems eliminate the sound of that amazing engine and reduce performance. While these may be instilled for the average joe, this isn’t the best for car enthusiasts like you and me.
We crave the roar of an engine! We want to hear the car through the full rev-range and immerse ourselves in our drive. Our cars are modified to extract every ounce of performance we can. Why not take advantage of the potential of a modified exhaust?
Types of Aftermarket Exhaust Systems
Axle-Back
An Axle-Back exhaust system is when everything after the rear axle is replaced. These are usually fairly inexpensive and provide a good sound upgrade. Unfortunately, an axle-back exhaust will typically not yield too much in terms of performance.
Cat-Back
C the most commonly seen aftermarket exhaust upgrade. This replaces the entire exhaust section at the catalytic converter out to the muffler tips. Typically, you will see a cat-back exhaust replace the piping, mufflers/resonators, and exhaust tips. This provides more of a performance gain over an axle-back while changing the sound more significantly. Price-wise, these will be more expensive than an axle-back system. Overall, a cat-back exhaust upgrade is one of my favorite car mods out there. It gives a great balance between sound level and performance improvement.
Header-Back
A header-back exhaust system is an entire exhaust system replacement. The exhaust manifold, or headers, and all of the piping and mufflers will be replaced. Depending on local emissions laws, you may replace or remove the catalytic converter. Overall, this is the biggest performance gain you can make from the exhaust system. However, take heed that the noise levels will be much higher than a cat-back exhaust.
Turbo-back
A turbo-back exhaust replaces all of the exhaust system and replaces the downpipe. For a turbocharged car, this will bring a huge performance increase. The turbocharger will spool up faster and be free-flowing for the gases to exit faster.
Benefits Of A Modified Exhaust
A modified exhaust system is designed to replace a section or the entire OEM exhaust system. The main goals of this mod is to increase horsepower, improve engine sound, and create an awesome aesthetic upgrade.
An aftermarket exhaust system reduces backpressure, allowing the engine to operate more efficiently. Reduced backpressure allows the exhaust gases to exit and not push back into the engine to mix with the fresh air coming in.
For turbocharged cars, a modified exhaust allows for the turbocharger to spool up faster and increase its potential for power improvements. This is accomplished because the turbocharger works off of the exhaust to spin the turbine. That is why you will see high performance cars with elaborate exhaust systems.
Lastly, an often forgotten benefit to a modified exhaust is weight reduction. A high performance exhaust is often made from lighter materials such as titanium. This allows you to shed a significant amount of weight off of your car. Weight reduction amount will fluctuate based off of the amount of mufflers or resonators, the exhaust size, and the material used.
Negative Sides Of A Modified Exhaust System
While I am a huge fan of modified exhausts, there are some downsides that come with it. Like all car mods, there are many considerations to take into account.
Legal Issues
Modified exhausts, especially if you live in California, can bring you unwanted attention. Anti-exhaust laws have rung up thousands of dollars in citations for enthusiasts all over the world. These requirements for exhaust systems can range from emissions approval to certain sound decibel levels. Please review your local laws prior to installing any modifications.
Too Much Noise
While we all know a modified exhaust is going to produce more noise, sometimes it can be too much. Cabin drone is the sound of the exhaust reverberating throughout the interior of your car. If you drive a car with bad exhaust drone for a long enough time, you will absolutely hate driving. When I had my Focus ST’s exhaust done, I explained to the shop that I absolutely cannot live with cabin drone. Fortunately, with the right piping and muffler, I avoided cabin drone altogether.
Can You Have Increased Power and Manage The Noise?
The answer is an undeniable yes. Today’s technology includes electronically controlled exhaust systems. These systems have valves that open and close depending on the desired noise level. Companies like Valvetronic and Pypes offer electronic cutouts for their systems. With a press of a button, you can have a muffled exhaust or you can open the pipes up for an unrestricted automotive concert.
How To Install An Exhaust System
Luckily, exhaust system upgrades are fairly simple bolt-on parts. A downpipe or headers upgrade may be more time-consuming for most cars. However, an axle-back or cat-back exhaust system is pretty simple to DIY or to get a shop to do it. If you are a DIY car-enthusiast, check out Engineering Explained’s install video!
If you don’t feel comfortable taking on this project yourself, contact a reputable exhaust shop. Having met many different exhaust shop owners and workers, they all love installing a high quality kit or fabricating one for you. In some cases, a fabricated cat-back system may be significantly cheaper than a pre-built one!
Conclusion
A modified exhaust on a car is a great modification. The cosmetic enhancement is provides lets the enthusiast express themselves and customize their car. Also, the performance improvements add more power and reduce weight, making your car faster! Lastly, the joy and pleasure you get from the car’s exhaust note is unparalleled. Modified exhausts are exactly the reason why I could never own an electric vehicle. Cars are more than tools to get from Point A to Point B. They are an extension of their driver and an outlet for creativity.
When looking into modifying your car’s exhaust, take into consideration the local laws and regulations regarding noise levels and car modifications. Also, remember that just because the exhaust is louder, it does not mean it is better. Cabin drone is a pain and can make your car unbearable to drive.
Regardless of what approach you take on your modified car, you will thank yourself for enhancing your ride’s exterior, performance, and driver experience.