When designing your engine for performance and winning races, you should at all times focus on getting the most air into your car as you can. The more air that can enter into the motor, the more fuel which can be combined with it and then ignited in order to create horsepower. The element of your engine which actually controls how much air is permitted to come in is called the throttle body. Go to emission control for more information.
The throttle body is pretty easy to spot. It is the circular or rectangular opening on top of, or on the side of the intake which can have one or more flat butterfly valves covering the opening. When you press down on the gas pedal with your foot, what you are really doing is opening up this valve on the throttle body to let more air in which in turn sucks more fuel into the engine.
Since more air equals more horsepower, does that mean that a bigger throttle body which lets in more air means you will be able to increase your engines performance? In general, yes. A larger throttle body will suck in more air, and as long as your engine is capable of keeping up with the fuel demand then you should see a horsepower increase. Performance-oriented throttle bodies are also often better able to provide precise control over how much air is entering, giving you a more accurate throttle. However, keep in mind that an engine is a system, and it should be treated that way. Bolt-on components like throttle bodies can help to improve your performance, but they work much better when matched with the proper valves, exhaust system and overall tuning.
Refer to emission control for more information.
For the ultimate in performance, the key is not to go bigger, but actually add supplementary throttle bodies to your intake. In fact, you can even add a throttle body for each cylinder in your engine. These are called individual throttle bodies, and together with a special intake they can provide a direct path to air for every cylinder individually. Individual throttle bodies are the ultimate in performance for this type of modification, but their implementation is fairly complicated.
Getting each of the throttle bodies to open at exactly the right time in tune with each other is a difficult proposition. Not only that, but out on the street potholes, speed bumps and just general road roughness can provide enough vibration to seriously interfere with the correct calibration of these throttle bodies. It is usually a better idea to reserve the use of ITBs for cars that will only be used on the track unless of course, you have the time and energy to devote to making sure that these throttle bodies stay in tune on your daily driver.
Whichever route you decide to go, whether ITB or larger single or dual throttle bodies, you need to make sure that you arent overloading your engines capacity. If you cant get enough fuel into your engine to make use of the extra air, you might actually decrease your performance. A larger fuel pump and fuel injectors with a higher flow rate can help to make sure that your new throttle body solution gives you the horsepower gains you are looking for. Visit emission control for further information.
(out of reviews)
