Some simple and some complex ways to increase your cars horsepower.
Simple Horsepower Modifications:
1. Reduce the cars weight. Do not store anything in trunk, change your steel hood to an aluminum one (if available), or better yet a carbon fiber hood. If these are not an option, you can excise some extra metal underneath the hood.Using lighter aluminum rims instead of steels one will help as well.
2. Change that exhaust system. Any leaks in the exhaust will reduce horsepower.
Removing the catalytic converter and straigh piping the exhaust will increase the horsepower of your vehicle. Replace or modify the exhaust header. If you need more horsepower above 6000 rpm, an aftermarket header can provide another 3-4 peak HP. Useless unless cat-back exhaust upgrade done first.
3. Change that stock air filter to a perfomance air filter such as K&N.
Let air come in more easily - As a piston moves down in the intake stroke, air resistance can rob power from the engine. Some newer cars are using polished intake manifolds toeliminate air resistance there. Bigger air filters and reduced intake piping can also improve air flow.
4. Reprogramming the ECU. You can also add a chip. Some people
have argued that the horsepower chip does not increase HP, but others
have said they have had remarkable results with these chips.
5. Boost your octane.
6. Change your engine timing.
7. Replace the flowmeter in the intake tract. If you will be using the motor above 6000 rpm frequently this can provide another 5 or so peak HP.
The flowmeter is very restrictive and limits HP above 6000 rpm, replacing it eliminates the bottleneck. The OEM flowmeter flows 165 CFM while a bone stock 1.6 motor at 7200 rpm flows 178 CFM, this means that the OEM unit is undersized for high rpm usage, the change probably won't be noticed below 6000 rpm.
8. Shaving the head. Compression = power. Shaving the head .010" will increase the compression ratio about a /4 point. I dyno'd this and it was good for about 4 HP and 4 ft lbs of low rpm torque. It is very noticeable across the entire rpm range. (I don't know what the shaving limit is but I have not heard of anyone going beyond .025".
FYI, the shop manual limit is .008" for 1.6 and .004" for the 1.8). As long as you have the head off you might as well R&R the valve seats too. Cost about $250 if you remove and put it back on yourself.
9. Increase the compression ratio - Higher compression ratios produce more power, up to a point. The more you compress the air/fuel mixture, however, the more likely it is to spontaneously burst into flame (prior to the spark plug igniting it). Higher octane gasolines prevent this sort of early combustion. That is why high-performance cars generally need high octane gasoline - their engines are using higher compression ratios to get more power.
10. Increase displacement - More displacement means more power because you can burn more gas during each revolution of the engine. You can increase displacement by making the cylinders bigger.
11. Change 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 horsepowerto your engine and can also improve fuel economy.
Complicated (and more expensive) Horsepower Mods.
1. Change the Ingition systems- Ignition 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.
2. Turbo And Super Charger - To get maximum horsepower out of almost any engine, a supercharger or even a turbocharger 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 turbo 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.
3. Nitrous Oxide System - 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.
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.