Truck Performance 101 - A beginner's guide
November 12, 2005
Today, the aftermarket gives truck owners more performance options than ever before. However, all the new products and gizmos can be a little hard to sort through. What you need for your specific truck will depend on what type of truck you have and what you use it for.
What is performance? Basically, it is the word used to describe speed, fuel consumption rate and towing ability. Performance is primarily measured in terms of horsepower (HP) and Torque.
Horsepower, or HP, is by definition, the power of an engine in comparison to horses. For example, a truck with 100 horsepower is as fast as 100 horses all rolled into one. Horsepower is often indicative of a truck’s top speed. Horsepower does not necessarily mean that a truck is fast from a standing start (see torque) but instead it is often indicative of the speed attainable by a particular truck. This being said other factors such as weight and grade will impact the final speed achieved. In more scientific terms, HP is the common measurement when rating an engine's power. One horsepower equals 500 ft-lbs. per second, which is basically the power needed to lift 550 pounds one foot off the ground in exactly one second or the power needed to lift 33,000 pounds one foot off the ground in exactly one minute.
Torque refers to a truck’s ability to generate pick up. Torque is one of the most important factors at the beginning of any non-rolling start. It is the ability of the truck to send power to the wheels and turn them - moving the entire truck forward. The dictionary defines it as: “The moment of a force; the measure of a force's tendency to produce torsion and rotation about an axis…”. The most important thing to remember is that torque is what gets the truck rolling and is very important in towing.
The basics of performance, of course, center on your engine. Think of your engine as basically a big air pump. It breathes air in through the air intake and breathes it out through the exhaust. The easier your engine can breathe the more performance it will deliver. The stock engine you received from the factory comes with OEM air induction and exhaust. Modifying these two areas is relatively easy and can deliver significant increases in both HP and torque. One other primary factor affecting your performance is the engines computer. The stock OEM computer your truck came with is set to a “safe mode” to protect the truck against virtually any driver error…e.g., redlining. Although these settings are meant to protect the truck, they can impede performance significantly. Tweaking your truck’s computer can significantly increase HP and torque while still providing safety to the engine. We’ll look at each of these three performance enhancements below.
The air intake primarily consists of your vehicle’s air filter. Stock air filters are made of pleated paper. The problem with pleated paper is it often tends to become clogged which greatly reduces the airflow. Fragments of paper are ingested or sucked into the intake system creating a hole for gritty contaminants to enter the engine. In addition, these filters have to be replaced often to maintain a basic level of performance. Aftermarket filters are made of cotton gauze or engineered foam. These filters, made by companies like K&N, Airaid, Green Filter and True Flow significantly increase the flow of air through the filter. In addition, these filters defend against dirt at twice the rate or more than their paper counterparts and most come with a lifetime warranty…that’s one filter for the life of your vehicle. Installation of these filters is super easy…just replace your existing factory air filter.
The second factor effecting air intake is the temperature of the air coming into the engine. You’ve probably noticed that your truck runs better on cold days. That is because the air is denser and denser air allows more combustion when mixed with fuel and ignited. Stronger combustion means more power to move your piston in the cylinder. Aftermarket companies…many of the same mentioned above…have developed systems called “Cold Air Intakes”, that move the point of air intake from the top of your engine, which is normally very hot, to a point outside the engine. The result is that the air being sucked into your engine is much cooler than it would be using the normal air filter location. Cold air intakes require a little more handyman skills that just replacing a filter. However, they can be installed easily by anyone that has basic tools.
Exhaust is the “exhale” to your engines lungs. The more twists and turns in the exhaust, the less your vehicle can breathe easily. Exhaust systems come with three primary elements…the muffler, exhaust pipes and muffler tips. The first two are the main ingredients that effect HP and torque. OEM factory exhausts are well made, but not designed to deliver maximum performance. Aftermarket systems from companies like Magnaflow, Banks and Gibson are engineered specifically for each truck and are designed to get the most out of your vehicle. In addition to more power, these systems also deliver an enviable “roar” that will let others know you have tricked out your truck. I do not recommend installing an exhaust system unless you are a true gear head and are prepared for cutting and welding. Although most muffler shops do not carry these products, they will be glad to install them for you.
Computer Chips and Programmers
Your truck’s computer is technically referred to by gear heads as the Engine Control Unit (ECU). The ECU that controls the engine is very complicated. OEM's program them to satisfy emissions requirements, meet EPA fuel economy requirements and protect the engine against abuse. The computer does this by controlling many aspects of the vehicles performance, but primarily controls the ignition, fuel injection and spark time. As mentioned above, the OEM’s set the default value of the ECU to an “ultra-safe” mode to insure adherence to government guidelines and to protect the engine from abusive driving. Aftermarket companies like Hypertech, Edge, Unichip and Superchips manufacturer chips and programmers that will either plug into your ECU or programmers that will alter the factory settings. Chip manufacturers set the products for each specific vehicle to a default performance setting. Programmer manufacturers allow more versatility in that they allow custom modifications to compensate for other performance add-ons like cold air kits and exhaust systems. These systems are relatively easy to install by anyone that has a little mechanical knowledge.
In conclusion, you can significantly increase your HP and Speed by just making these basic changes to your truck. Some all-in-one kits can deliver up to a 40% increase in overall performance. Finally, contrary to rumor, none of these products will void the warranty of your truck. There is a federal law called the “Magnuson Moss Warranty Act” that prevents automobile manufacturers from voiding warranties from the addition of aftermarket products. These are just a few of the many performance products available from the aftermarket. I will be covering more advanced performance products, like superchargers, in a subsequent article.
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