How to Increase your Engines Horsepower
There are many ways to increase an engines horsepower rating. The automobile engine is basically just a large air pump. Easing the flow of air into and out of the engine will increase power. As built from the factory an engine has some basic shortcomings, eliminating these will increase overall efficiency and power.
The compromise between overall efficiency and quiet operation is one shortcoming of the factory design. The reason high performance cars have loud exhausts, is because loud pipes increase airflow, allowing burnt exhaust gasses to exit the engine easily. Installing exhaust headers on the engine, instead of cast iron exhaust manifolds, is one of the most beneficial and cost effective modifications you can perform.
To go along with the headers, free-flowing catalytic converters, large diameter exhaust tubing, and low restriction mufflers will go a long way to reduce back pressure. Back pressure is the restriction present in the exhaust system. You can't get the fresh air in until you get the stale air out. Horsepower gains on the exhaust side of the engine, are usually easier to obtain than on the intake side. Which makes it one of the first places most hot rodders look to for performance increases.
Keep in mind that by decreasing back pressure you reduce pumping losses, which is the effort the engine must use to fill its cylinders with air. Increasing engine efficiency has the added benefit of increasing fuel economy as well. As long as you can resist the urge to show everyone your new-found horsepower at every stop-light.
On the intake side of the engine is where the factory generally installs a very restrictive air cleaner assembly. The factory is trying to eliminate that "VOOOM" sound of air rushing into the engine at all costs. Those costs usually being less horsepower, and lower fuel economy. A high performance air filter is a minimum requirement here, models made by K&N are considered to be the best made.
The air filter ducting is another area to find power, the factory pleated tubing adds tremendous turbulence to the incoming air. An aftermarket smooth tubing set will increase power substantially. Installing a larger throttle body or carburetor allows for more airflow, and is usually the next addition to the power seeker.
Reducing parasitic drag from the engines belt driven accessories, is as easy as installing an under-drive pulley on the crankshaft. These pulleys slow down the speed of all the items driven, and are available in various under-drive ratios. Use caution here, don't automatically go for the smallest pulley. If you slow your accessories down too much, your car could overheat on a hot summer day. Or you may find out, that your battery doesn't charge if you do a lot of slow city driving.
While reducing drag on the engine, you may want to consider either a flex fan or an electric cooling fan if your car is not already equipped with one. A high performance computer chip is also an easy way to optimize your engine for the type of driving you do. Computer chips are available in various states of tune from mild to wild, some even have more than one setting pre-programmed into them. This gives you the ability to set the chip to high perfomance mode for cruise night and then return it to stock, before you hand the keys to the valet at the restaurant.
