Other than adding a flashy look to a semi, exhaust stacks have immense benefits to the design of semi trucks and engines as a whole. From their direct influence on the functionality and performance of the engine to how they simply affect the drivers around the truck, exhaust stacks play an important role on semi trucks.
What is the Purpose of Exhaust Stacks on a Semi Truck?
Exhaust stacks are how semi trucks cool their engines and get the used hot air out of the way for the engine to continue its performance. Stacks also are in place to keep soot and smoke out of the eyes and lungs of the truck driver.
They also protect drivers who pass by or drive near the truck, which allows for a better field of vision for all. While it may seem simple enough, here is a more in depth look at how exhaust stacks function on a semi truck.
Why Do Semi Trucks Have Dual Exhaust?
There are multiple reasons that two exhaust stacks are on some semi trucks. With two exhaust pipes, there is more airflow allowing any fumes to be expelled faster. This is beneficial in two ways.
It can be much quieter because there is not as much gas being forced through a smaller area as well as helping the engine to run better by keeping it cool. Some studies have shown that in the right environment and with the right engine dual exhaust stacks can improve the overall horsepower of the engine.
Do Stacks Add Horsepower?
They do not directly add horsepower to the engine. But because of the way they allow the exhaust to escape, it allows the air in the engine to be expelled faster and in larger volume allowing the engine to continue the next exchange. Overall it helps the engine perform more efficiently and powerfully.
How Do You Measure Semi Truck Exhaust Stacks?
There are multiple measurements and pieces that go into an exhaust stack installation, the exhaust, the spool, and the stack. For the exhaust, there are two measurements that you will take when measuring them.
There is the measurement of the inner diameter of the hole of the exhaust pipe, commonly referred to as the ID, and measuring the outer diameter of the exhaust pipe, which is referred to as the OD. Those two diameters will help you determine the size of the other pieces that will attach.
For both the spool and the stack, there is much more that goes into those measurements and how they are to be measured will vary by the maker of the truck. The best solution most likely will be to reach out to the company that makes your truck or even see if they have information on their website about how the measurements are to be done.
What Happens When Water Gets In The Exhaust System of a Semi?
The most common answer is that it simply doesn’t. Most exhaust stacks either blow the water out or it doesn’t allow it to even enter at all because of the force from the air.
Some exhaust stacks have a rain flapper which is a light cover on a hinge that opens the exhaust stack when it is blowing out and then it falls back down to prevent the water from coming back in when air is not coming out.
There are even some trucks that have a drain at the bottom of the stack that is lower than the engine to prevent any water from building up inside. But if a truck is sitting overnight or in a storm, it is not uncommon for truckers to put covers on the tops of the stacks.
How Do I Identify a Worn Out Exhaust Pipe On a Semi Truck?
When your exhaust pipe needs to be replaced there will be multiple signs, although you may not see them all at once. You will hear an increase in the sound of the exhaust. The sounds could be in the form of rattling or other sounds.
Your engine’s performance will decrease. This will be in its overall fuel efficiency. There could also be an exhaust smell in the cab leading you to believe there is an issue.
Lastly, you could possibly even notice a soot trail left from the exhaust. These are just some of the things to look out for if you suspect that your exhaust pipes need to be replaced.
Things to Consider With Semi-Truck Exhaust Stacks
Here are some tips for you to keep in mind in regards to your truck exhaust system.
Materials
When it comes down to it all exhaust stacks are made of the same materials. They all are some form of metal with a chrome finish. You will find that most sellers only list their stacks as chrome-plated metal.
This chrome plating helps to prevent rusting and wear and tear that could otherwise destroy any exhaust stacks. Be sure though to look into reviews of products to be sure that there is not a tendency for the chrome finish to flake off or easily wear off in any way.
Temperature
The point of exhaust pipes in any vehicle is to cool the engine and expel any air that is in the engine. The faster the air escapes, the faster the next exchange can begin. But when the air leaves it also allows all of the heat to go out with it.
This helps prevent the engine from overheating. With the properly sized exhaust stacks, and of course no obstructions, the stacks will directly affect the performance and health of the engine.
Replacement Pieces
When it comes to replacing or improving any pieces on a semi truck, the price can be rather significant. That being said, when a piece needs to be replaced it has to be done.
You’ll want to make sure that you get the proper width and length pieces to attach to the current system you have. Be sure to reference any guides from the company that designed your vehicle or consult a professional in that area.
Field of Vision
One of the primary reasons for exhaust stacks is that it keeps smoke and exhaust fumes from being pushed out low at the level of most drivers around them. If the exhaust pipes were at the bottom as with most vehicles, all of the smoke would be covering windows and getting in the air circulation of the drivers around them causing a distraction that could possibly lead to an accident.
1 Exhaust Stack vs 2 Exhaust Stacks
Both dual and single exhaust stacks are beneficial in the right scenario. It has been argued that dual exhaust stacks have no benefits and are simply for cosmetic reasons.
But according to some creators and dealerships for semi-trucks, a dual exhaust stack is for a stronger engine. With a set-up involving 2 exhaust stacks, there is more space for air that can be pushed out allowing for the engine to start the next exchange quicker.
With a single exhaust stack, there is not as much room for the air to be pushed out but that has not always been shown to be an issue, especially in more modern trucks. With technology advancing as it has, engines are able to function more efficiently. In the end, it comes down to the truck itself on whether a single exhaust stack or dual exhaust stack is better.
Making Mechanical Measures of Excellence
Keeping your truck at peak performance is key to staying on the road and getting your work done. Whether you’re replacing a couple of exhaust stack pieces or rebuilding an engine, care of your vehicle is key.
Having the mechanics of your engine and everything around it brings a certain level of excellence that those you work with will quickly appreciate. Make sure to take the time to learn about your truck and the trucks you work with regularly to become a better trucker as well as an asset to your clients.