A Beginner’s Guide To Exhaust Systems
At Foreign Affairs Motorwerks, we like to think of the internal combustion engine as a giant air pump. The more air it can move efficiently, the better the performance. When it comes to airflow through the engine, exhaust systems consist of three main components:
The Intake
Responsible for the flow, filtering, metering, and fueling of fresh air coming into the engine.
The Engine Block
Compresses and burns the fuel rich air to extract energy.
The Exhaust System
Removes the used, de-oxygenated air from the engine while providing sufficient back pressure to keep the engine running smoothly.
As you can see, each one of these three components would need to be functioning as efficiently as possible in order to maximize your performance auto’s power. When it comes to exhaust systems, manufacturers have to compromise. One side of the scale is loaded with performance and power, the other is weighed down by noise and air pollution coupled to economic gas mileage. Even the most performance orientated marques like Ferrari, Porsche, and McLaren are continually squeezed by the administration to meet stringent government regulations. Others, like BMW and Audi, will focus on gas mileage and noise for executive saloons. Regardless of what your personal taste in the vehicle is, the stock exhaust will restrict your power output.
Fortunately, we owners aren’t restricted and there are many, many different kinds of exhaust modifications you can use to express your creativity and boost performance. We’ve ranked them from mild to wild.
Tailpipe Upgrades
The easiest and cheapest exhaust modification is to change the tailpipe design to a custom fitting. If done right, this can change the back pressure of your system and lead to greater performance while also improving the exhaust note. We have a wide range of different tailpipes available, so why not pop into our shop and take a look at the possibilities?
Cat-Back Systems
Cat-Back is mechanic slang for the part of the exhaust system from the catalytic converter back to the tailpipe. Often manufacturers have carefully calibrated the engine management system to work with the pressure created by the catalytic converter and incorporated sensors inside it to keep track of exhaust gasses. That is why it is often cheaper and more effective to modify the system after the converter since changing it completely can mean modifying the vehicle engine management computer, which can be a costly process.
Many manufacturers like Akrapovic make off the shelf cat-back systems for a wide variety of models allowing decent performance gains at a minimal cost.
Complete Replacement
This is not for the faint of heart and is really the ‘blank canvas’ approach similar to what Apple is about to do with their Macbook computers (can be rather hit or miss).
The exhaust system officially starts with the exhaust manifold (or header) which bolts directly onto the engine block. These are responsible for collecting the hot exhaust gasses the engine ‘pulses’ to the exhaust. Most stock manifolds are cast, and in your mass-produced mainstream marques they can be rough inside, which causes the gas from one or more cylinders to become turbulent. Fitting a custom header will often equalize the flow and make for a smoother torque/power curve.
Smooth headers are nothing unless the exhaust flow continues to be balanced until it leaves the system, and this is where cross pipes or H-pipes come in. More is always better, so instead of using one pipe, why not use two? Two pipes ensure even flow and are especially good in engines with multiple cylinder banks like vees or w configurations.
Finally, your downstream ‘boxes’ (mufflers) need to be selected to give you optimal flow, enough back pressure to keep the motor purring, and a beautiful exhaust note. The whole system then terminates with a custom set of tailpipes, and the engine management map gets optimized using a dyno to ensure power gains across the rev-range.
Exhaust System Modifications Near Me
Just like you don’t enjoy a blocked nose, neither does your auto. We hope that we haven’t exhausted you with all this information, but if you’re feeling a little muffled by your face-mask why not pop into our Pompano Beach Shop (yes, we are open) and talk it over with one of our ASE-Certified team?