It seems that car enthusiasts have an instant desire to upgrade their exhaust system after buying a car. Even if that means changing only the back tips for added style. This obsession with performance exhausts dates back from the first days of automotive racing. Wide tubes emerging from the engine always meant that the car was powerful and fast. But, in today’s world where vehicles come optimized in every area from the factory, do you really need a performance exhaust?
Truthfully, there is no straight answer to this simply because not all performance exhausts are the same. Most of the upgrades people do consist of back tips which only add to the looks of the car. If you want to add performance, you might need to pay much more for cat-back or header-back exhaust system. Then, there’s the issue of noise (regulations) and price. Some aftermarket systems that will make your car more powerful may be way out of your budget.
To help you choose the best performance exhaust for your needs, we will answer some questions most car enthusiasts have about these systems. But first of all, let’s explain why the exhaust is essential when it comes to performance.
What Are the Main Parts of An Exhaust System?
Almost every modern exhaust system consists of the following parts:
- Exhaust manifold – takes the exhaust fumes from the cylinders. It is situated in the engine bay and is also known as a header.
- Catalytic converter – one of the most critical parts in a modern vehicle. The catalytic converter filters out poisonous gasses such as NOx, CO, and hydrocarbons.
- Resonator – meant to filter out noises from the engine at specific frequencies.
- Muffler – another part that lowers the noise that comes from the engine. The muffler sits in the back of the vehicle, usually around the rear axle.
All of these exhaust parts are connected with piping that takes care of delivering the gasses from the engine to the back of the vehicle.
How Does A Performance Exhaust Increase Horsepower?
By the basic principle of fluids (gases are a fluid) traveling in pipes. Generally, gases go faster in tubes with smaller diameters and slower in pipes with a larger diameter. However, fluids still move more freely in pipes with a larger diameter.
For example, when the engine is at low RPM, pipes with a small diameter can help it breathe better. In this case, the engine produces less gas, and the higher speed in the pipes is beneficial. That said, small tubes can limit the flow at higher RPMs and choke the engine. The result will be a significant loss of power.
When car manufacturers design exhausts, they tend to choose a diameter that is in the middle. This way, the engine works optimally at lower and higher RPMs. Performance exhausts tend to have larger pipes more often than not. This means that your motor might lose a bit of the low-end potency, but it makes gains at higher RPMs.
Some high-end exhaust manufacturers take things to a higher level with designs that bring improvements on both fronts. Their designs include narrow and wide tubes for a combination of low RPM torque and top RPM power. These systems also have mufflers and resonators that allow for better airflow.
We will, however, not dive that deep into engineering a sound exhaust system. These companies have experienced engineers and a lot of R&D that results in products that can improve the power of your engine. That’s why high-end performance exhausts tend to cost much more than low-end ones.
What Is the Best Type of Performance Exhaust System?
Generally, there are three different types of aftermarket exhaust systems. More precisely, they differ by how much of the exhaust system you replace or improve.
The best type of performance exhaust systems is the header-back. This means that the system completely replaces the factory system from the header to the back of the vehicle. Thanks to this, exhaust manufacturers can make more significant gains in power and torque. However, header-back exhausts are also the most expensive of the bunch.
If you only want a slight increase in power and better sound, a cat-back exhaust might be a better choice. These exhausts only replace the stock piping that goes from the catalytic converter to the back of the car. Obviously, they don’t add as much power to your vehicle, with the difference often being negligible. However, some cat-back systems sound very good and if that’s what you’re looking for, then go for them!
For people that are very tight on budget, there is an even simpler solution. The axle-back exhaust only replaces the piping from the rear axle to the back of the car, and the muffler. These systems won’t improve power much but may add noise (if that’s what you want). The positive aspect of axle-back exhaust systems is that they are pretty inexpensive these days.
You can also replace only the exhaust system tips. They are generally meant to improve the looks of your car and won’t do much in the performance department.
How Much Does An Exhaust System Cost?
The price of aftermarket exhausts varies depending on the type of your car and the quality of the system. Clearly, header-back exhausts are the most expensive and range from $800 to over $2000. Cat-back exhausts, on the other hand, cost from $400 to $1200, while axle-back exhausts are slightly cheaper. You can also replace the muffler for $100 to $300, while you can purchase exhaust tips for $25 to $150. There is also the added labor cost if you replace the exhaust at a mechanic.
Does Aftermarket Exhausts Add Horsepower?
By making your engine breathe better, performance exhausts can extract more power at certain RPMs. However, not all engines gain that much power. Smaller four-cylinder engines will gain much more power than large-displacement V8 engines. The more powerful the engine is, the less work it has to do to beat the restrictions of the exhaust. Also, cars that are already performance-tuned from the factory might not see improvements in power whatsoever.
Does Aftermarket Exhausts Improve Fuel Economy?
As expected, as much as a performance exhaust system improves power, it can also improve fuel economy. This is because performance exhausts enhance the air-flow of exhaust gases, which makes engines more efficient. The highest-quality aftermarket exhaust system can improve the fuel economy by up to 5%, which is a pretty amazing result. Nonetheless, some cheap and low-quality exhausts may hurt fuel consumption.
Other Benefits of An Aftermarket Exhaust
Better sound is the next thing that comes to mind. Most stock exhausts are tuned for lower noise and better comfort. Let’s take the Toyota 86 and Subaru BR-Z for examples. Both of them are sporty coupe’s for car enthusiasts, and both of them sound ordinary. A high-quality aftermarket exhaust can significantly improve the sound of these cars.
However, some exhaust manufacturers tend to overdo things. While louder exhaust might seem like a great solution, it becomes tiring after a few days. The most desired characteristic of a sporty exhaust is “louder during acceleration, quieter on the highway.” Keep in mind that systems with this character cost much more than systems that only add noise. Also, always look for exhausts that are within regulations, or you might be looking at a fine in no-time.