Don’t be a “TRD”

Have you ever heard somebody sarcastically say “T.R.D” when a loud car passes by? This would mean that car was either too fast or incredibly slow.  In the automobile performance world, the TRD acronym stands for Toyota Racing Development, a racing arm of one of the biggest car manufacturing companies in the world. Unfortunately in our native Bisayan dialect, TRD is short for “tingog ray daku.” This means the cars pace doesn’t match the exhaust note that it’s making.

Exhaust systems are one of the most common entry-level performance modifications out there both in cars and motorcycles.  Some change exhaust system for the extra power that it brings, some simply for the exhaust notes.  It’s common knowledge amongst enthusiast that changing to an aftermarket exhaust system will help their car’s engine make more power and anyone can hear when a performance exhaust sounds great.  But not as many people understand the components included in a performance exhaust system and how each of them help your engine make more power. Like most of the car’s components, the exhaust is pretty much a scientific thing. Yet some people just do a “go ahead – do it yourself “system which will inevitably give you more noise than speed.

Here is a quick explanation of the principals at work in your vehicle’s exhaust system and how each component works.

As your vehicle’s engine burns fuel, exhaust gasses are produced as a byproduct and they have to be moved out of the cylinder and away from the engine. However the gasses produced are very hot and potentially harmful and they have to be properly contained. This is the exhaust system’s job. This containment of the gasses is a potential problem from the performance perspective. If pressure develops in the exhaust system, that makes it more difficult for the engine to expel gasses. It has to “push” harder to force the waste gasses out. This phenomenon is known as BACKPRESSURE, and it is one of the primary restrictors of engine power. However, a little backpressure is needed in lower rpms (revolutions per minute) to create torque (rotational force) as it helps keep the intake charge where it belongs by slowing the escaping exhaust gases. So basically, you cannot go too big or too small with your exhaust system. 

Here are some of the most common exhaust modifications and a quick explanation of how they use these components to increase efficiency, if not the exhaust note that it creates.

High Flow or  Free Flow Muffler

High performance mufflers offer an increased flow capacity over OEM (Original Equipment Manufacturer) Mufflers. Although mufflers aren’t usually the most significant obstruction to the exhaust stream, an aftermarket muffler can reduce backpressure enough to free up a couple extra horsepower. Choose the one that is suited for your car. If you have a naturally aspirated engine, get a 1 1/2” to 2” diameter muffler. If you have a forced-induction engine(turbo) ,2 ½” to 3” would be enough. You wouldn’t want to overdo mufflers sizes as it will detune your exhaust note and give you a “RICER LOOK” (Race Inspired Cosmetic Enhancement)

Custom Exhaust  Manifold or Headers

Exhaust headers are custom made pipes that replace the exhaust manifold on the engine. The performance increase is realized mostly because of the efficient distribution of exhaust gases. Custom exhaust manifolds are designed to separate the exhaust stream of the different cylinders, letting gasses escape freely and uniformly, and increasing efficiency.  Custom or Aftermarket Exhaust Manifolds and Headers are available in Auto Accessories and Car Shops. Be extra cautious and do some research in choosing these as some will produce a good exhaust notes but will not relate to increase in power.

Large Diameter  Exhaust Pipes

Larger diameter exhaust pipes allows more space for exhaust gasses to exit, and helps move them away from the engine more efficiently, reducing backpressure. Like the mufflers, this component should not be overdone. Extra large diameter exhaust lines don’t necessarily relate to power.

High-Flow Catalytic Converters

Most modern vehicles have catalytic converters and it’s illegal to take them out according to Se. Legarda’s Clean Air Act. But it’s the most obstructing element in the exhaust system. It’s a good thing there are aftermarket high flow converter is available to help exhaust gasses move past this bottleneck faster, reducing backpressure, and yes, giving you the “proper” exhaust note.