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Air Filters |
The first and fastest way to get more power out of any engine is to get more air into the engine and more exhaust out. A high-flowing, low restriction air filter setup is the way to start. Perfornace air filters are available for almost any truck application. Horsepower gains vary, but you can expect a 5-10 horsepower gain in most applications.
The stock exhaust system found in most trucks is a soruce of great flow restritcion. By replacing the exhaust system, you will discover a dramtic increase in power. The simple, and most popular method to gain some power is to install a cat-back exhaust system, which replaces the stock exhaust from the catalytic converter to the tailpipe. These systems incorporate a high-flow muffler and often use larger-than-stock diameter tubing, which is mandrel-bent to eliminate crimping when the tubes are bent. Several manufacturers produce cat-back exhaust systems specially made for each model truck.
There are a few important things to consider when choosing a system for your truck. The material used in a cat-back system is usually aluminized steel. Aluminized steel exhaust systems are cheaper, but they won't last as long as stainless steel. For maximum durability, and if you can afford it, choose a stainless steel exhaust.
Exhaust systems vary greatly in exhaust tone, in-cab noise, and fit. Keep those things in mind when deciding on your exhaust system. Another consideration is the exit location of the exhaust. Several manufacturers offer rear or side exit systems. You may also have the choice between single or dual-exhaust outlets. If you plan on installing your own cat-back system, remeber that although the new exhaust may be a simple bolt-on operation, removal of your old system may require cutting.
If a cat-back system isn't available for your truck, you can purchase a high-flow muffler and fabricate your own system using larger-than-stock tubing, or have your muffler shop build one for you. A good cat-back exhaust or high-flow muffler can add up to 15-20 horsepower to your engine, and may also help with fuel economy.
For a mild boost of power, start with a high-flow air filter and a cat-back exhaust system. To keep your engine running cooler and more efficiently, you can add a low-temperature thermostat, such as a 160 degree thermostat to replace the stock 180 degree found on full-size Chevy trucks.
If your truck engine is controlled by a computer, chances are you can gain power and performance by installing a computer upgrade. Most trucks can use a replacement PROM (Programmable Read Only Memory) chip. These chips can alter the air/fuel ratio, idle speed, and spark timing of your engine depending upon different operating conditions. Most changes occur at or near wide open throttle. Most chips sold by large manufacturers are made for stock or near-stock engines. Examples include ADS, Z Industries, Hypertech, and JET. If your engine has been heavily-modified, you will need a chip which has been programmed for your application, some chip manufacturers, such as Z Industries, allow you to specify parameters and can make custom chips, or change a chip's settings.
Trucks produced from 1996 to current use an OBD-II (On-Board Diagnostic) system which can not be modified using a new chip. These new systems must be reporgrammed. When making upgrades to these newer trucks, the OBD-II should be reprogrammed. Hypertech offers the Power Programmer and JET makes a Power Control Module. These systems make changes easy, and they can control ignition timing, fuel injection performance, and even automatic transmission shifting points.
Computer chips and reprogrammers can add up to 20-30 horespower, especially if you have already added a cat-back exhaust system and performance air filter. Some chips and reprogramming units require the use of premium gasoline, which may be an important consideration if you want to keep your fuel costs down.
Underdrive pullies usually consist of crankshaft and alternator pullies. These increase horsepower by reducing accessory drag. Pullies can benefit almost any engine, large or small. Installation is a snap, but there are a few disadvantages to underdrive pullies. Because the alternator is turning slower, it won't be able to produce the current needed to keep the battery charged when running at idle. If you leave your truck on idle for extended periods of time, you may want to only install the crankshaft pulley. An underdrive pulley set can add up to 15 horsepower to your engine and can also improve fuel economy.
Aftermarket headers can be bolted in place of the stock cast-iron headers. Small block headers usually use 1-5/8-inch primary tubes and big-block headers use 1-3/4-inch tubes. An important consideration when choosing headers is quality of materials. Header tubing vary in thickness, but a good quality header should use between 18-gauge and 14-gauge tubing. The metal used in the header is also important. Some headers are mild-steel, which will rust and corrode over time. Headers can be coated, either with a ceramic coating or a high-temperature paint. Using 100% stainless steel construction eliminates the need for coatings, but it is usually out many buyer's budgets. When headers are shipped, they sometimes come painted. Be aware that this coating is only for rust prevention during shipping, and the paint will not hold up to the heat once the header is installed. When headers are added along with a cat-back exhaust and high-flow catalytic converter, you can usually gain 20-30 horsepower over stock.
When installing headers, you should add a monolith-style catalytic converter to replace the stock unit. Old or plugged pellet-style converters should also be replaced. Federal and state laws do allow the replacement of catalytic converters, but removal is illegal, and can actually harm your stock engine's performance. High-flowing performance catalytic converters are available from many companies. Be sure the catalytic converter you buy is made for your engine size, installing a 4-cylinder converter on a V8 will have a negative impact on exhaust flow. Another consideration is the material used in construction. The body of a catalytic converter is usually made of stainless steel, but the inlet and outlet tubes are often made of mild or aluminized steel. If you care about the longevity of your exhaust system, find a high flow catalytic converter that has stainless steel inlet and outlet tubes.
Ingition systems are also another source of added power. A performance iginition control can increase spark output over the whole power range. A complete ignition system upgrade should include new wires, and the spark plug gap may need to be increased to take advantage of performance ignition system. Older trucks usually benefit more than newer trucks. Although some truck owners experiemce little or no difference with a new ignition system, others find mild gains in fuel economy and power.
Most late-model trucks with electronic fuel injection use a TBI (throttle body fuel injection) system. TBI engines can benefit from the addition of a high flow intake manifold (such as those produced by Edelbrock), blue-printed throttle bodies, or TBI spacers. Companies such as Turbo City, Arizona Speed and Marine, and others offer several Chevy Small Block and Big Block TBI upgrades. For an even greater increase in power, a tuned port fuel injection system swap is available for those with TBI. TPI Specialties, Arizona Speed and Marine and ACCEL produce TBI to TPI kits.
Free-breathing cylinder heads are a good source of power. An alternative to expensive performance head replacements is to have your stock heads extrude-honed. This process will smooth out the intake and exhaust ports and will greatly improve flow characteristics, at a fraction of the cost of new heads.
Camshafts can also greatly improve your engine performance. There are many things to consider when installing a new cam. Roller camshafts offer a smoother idle, a broad power range, and strong top end, but they are much more expensive than standard flat tappet cams. A standard hydraulic cam is still a good choice, and proper planning will reward you with srtong and reliable power. For a daily-driven truck, with compression between 9.5:1 to 10.0:1, 215 degrees is about the maximum .050-inch duration. With a lower compression engine, below 9.5:1 no more than 210 degrees of intake duration should be used.
Superchargers and
Turbochargers
To get maximum horsepower out of almost any engine, a supercharger or even a trubocharger system can be bolted on for an easy 40-50% increase in power, often adding 100 or more horsepower to a V8 engine. Supercharging is available for most V8 engines, but there is a limited availability of bolt-on systems for V6 and four-cylinder engines. If a supercharger system is not available for your engine, you can try looking for a trubocharger system. Smaller engines can benefit from a trubo system.
Both superchargers and turbochargers work on the same basic princliple. They force-feeding your engine both air and fuel. An increased density of air and fuel in the combustion chamber of your engine means more power on ignition. It is a means to increase your engine's compression ratio. The basic difference between superchrgers and turbochargers is that a supercharger is belt driven and relies on engine power to run. Turbochargers run off of exhaust pressure.
The most common type of supercharger, the Roots-type blower, compresses the air in the intake manifold. Common examples include the B&M and Weiand supercharers. These systems work great, but the disadvantge is that the air discharge temperature is rather high, meaning that although the pressure inside the intake manifold is increased, the air is hotter and can't hold as many oxygen molecules.
The other type of superchargers are real compressors. They compress the air inside the supercharger unit. Common examples are Paxton, Vortech, and Whipple. These systems usually have lower air discharge temperatures compared to Roots-type superchargers. Superchargers are driven by a belt, which uses engine power to run, and although a supercharger may use about 10-20 percent of your engine's power to run, the good news is that the overall engine output is up to 50 percent greater.
There are a few things you should know when you looking for a supercharging system. Air dischrage temperature is a measure of the air as it exits the blower. A higher tempertaure means a lower density of oxygen and fuel. Boost is the amount of pressure created by the supercharger. Put these two together and you get the supercharger's efficiency. Don't be fooled by high boost levels, they do not necessarilly mean more power. In order to reach higher boost levels, the blower must turn at higher speed, and thus more heat is created. However, there is an answer to heat. Intercoolers can lower the intake temperature. But even intercoolers have a disadvantage: they reduces the amount of boost pressure.
Most supercharger systems produce a mild boost of 5-7 lbs, which can be handled easily by a relatively stock engine. If you have a little technical knowledge, you can perform the installation in your driveway in about a day. Before you add your supercharger, you will need to upgrade your exhaust with a minimum of a cat-back system. A set of headers and a high-flow catalytic converter are also reccomended. You should also use a low-temperature thermostat (160 degree), and an ignition system that will retard timing as the boost pressure rises. If you're not already using high octane gas, you'll need to use at least 92 octane with your new supercharger system. Additional items such as high-flow fuel pumps and computer upgrades may also be necessary, depending upon which supercharger you use.
If you really want the power, advanced systems can produce 25 lbs of boost pressure or more. But these systems expensive and require a specially designed engine that can handle a high compression ratio. For a simple boost, though, a mild system with 5-7 lbs. of boost should a lot to wake up your engine. Best of all, most superchargers are legal in most states, and some systems are legal in all 50 states.
For the maximum horsepower when money is in a pinch, and for instant power on demand, there is no substitute for nitrous oxide. Nitrous oxide works by delivering high amounts of oxygen to your engine. Nitrous oxide is stored in high pressure tank at about 900 psi. At this pressure, nitrous oxide is in a liquid form. When it is released into an intake manifold at atmospheric pressure, it changes to a gas and expands, giving off high amounts of oxygen. As you add this boost of oxygen, you also get a lower manifold temperature because of the phase change of the nitrous oxide from a liquid to a gas. But too much oxygen can become a problem. High levels of oxygen alone will cause detonation and engine damage. To keep things safe, the ratio of air/fuel must be kept in check, so additional fuel must be delivered when the nitrous system is running. To keep enough fuel running into the engine, 3/8-inch fuel lines are a minimum, and a high-output fuel pump is also necessary.
A simple nitrous system consists of a plate that is installed between the fuel injection system (throttle body or carburetor) and the intake manifold. The plate injects both the nitrous and fuel when activated. Such a systems add a tremendous amount of power, somehwere in the range of 100-200 horsepower. These systems are safe as long as they are installed properly, designed by a reputiable manufacturer, and used with intelligence. It may be illegal to use nitrous oxide on your street-driven truck, check your local laws first. More complicated systems use individual nozzles, one per intake port. These systems deliver even more power, up to 350 horsepower, but they also require a highly modified engine.
