ALT-2 How to Increase Horsepower
Nearly everyone finds themselves wanting a bit more out of their car from time to time. There's that drag race down the freeway on-ramp or, sometimes a bit more nerve-wracking, the two-lane highway pass when you can see that on-coming truck on the horizon. For whatever reason, you've become used to your car's power and it certainly couldn't hurt to have a little more on tap when you need it.
Before you get started modifying your car, be sure it's in tip top condition! A simple tune-up can bring a sleepy car back to life, providing improved performance, but also increased fuel economy and overall reliability. Start with a clean slate; if not for your own safety and convenience down the road, in order to realize the largest gains from any modification you perform.
The basic rule of making more power is simple squeeze more air and fuel into the combustion chamber. All internal combustion engines draw air and fuel into the chamber, compress it, and detonate it. The resulting explosion forces the pistons back down the cylinder, which rotates the crankshaft, etc.. Increasing air and fuel must be done properly. To add more air and not match that air with more fuel or vice versa could spell disaster. So the trick is making sure you get both more air AND fuel into the combustion chamber.
Next, don't be swayed by common myths about how higher octane fuel will give you more power. Just the opposite, really! Higher octane fuel is more resistant to ignition! That's right. It actually takes MORE energy to ignite higher octane fuel. Now, this isn't to say that you should buy the lowest grade of fuel, either. Barring extensive modifications, you need only run the minimum grade of fuel specified by the manufacturer. Running lower than recommended octane can result in damage, while running more octane than required results in reduced engine efficiency and a lighter wallet.
Also be wary of too-good-to-be-true gimmicks like "performance chips." Modern engines are controlled by advanced computers which monitor a wide range of system inputs through several redundant systems. You're not likely to find a chip on any of these computers which can be replaced unless you're an electronics engineer. Trying to fool the computer with a "magic" chip you found online isn't going to work. Sorry.
All theory and wishful thinking aside, the road to increased power begins with making your intake and exhaust systems more efficient. Replace your air filter with a high performance, washable unit. You don't have to buy a brand name cold air intake system if you don't want to. Replacing the filter is nearly as good! And consider replacing the factory exhaust with an aftermarket system while you're at it for even more power and that sporty sound. Work your way backwards, replacing restrictive stock intake and exhaust components until you've reached the engine from either end. At this point, you'll be ready to consider the more advanced modifications.
With the intake and the exhaust addressed, you'll be at the point where you have to decide just how much of an investment of time and finances you wish this project to become. One the one hand, you could remove the intake manifold and the head (note: V-engines will have two heads) to have machine work done, perhaps install a set of aftermarket camshafts, and complete a list of proven airflow improvements internally. Or you can consider forms of forced induction such as the supercharger or its more common cousin, the turbocharger.
Both the turbo and supercharger are proven methods of greatly increasing the power output of an engine. These devices force more air into the combustion chamber (while larger fuel injectors add more fuel to match it) in order to generate exponentially more powerful explosions. Just like with balloons, the more air you force in there, the louder the bang. While a supercharger is a compressor turned by a belt attached to the engine at all times, a turbocharger uses the exhaust gas to spin the compressor. There are benefits to each method of forced induction, so careful research should be done into each if you wish to consider making power on a larger scale as this.
The more powerful the car, the more expensive the project will become, but nothing worthwhile was ever free or easy, was it? Never forget the basics: The efficient flow of air and fuel into and exhaust out of the engine results in more power. Modify accordingly. Keep in mind that power is nothing without control, so a few power modifications combined with a well thought-out (and much more easily installed) suspension system and a really good set of tires will give your car that sporty feeling all the time - not just when you mash the gas pedal to the floor. If you seriously evaluate your goals for the car when it's complete, your goals will serve to guide you and you towards the most rewarding experience.
