The weekly racer faces some very real challenges with fuel systems. These problems are manifest in trying to make a fuel system that was designed for passenger cars feed an engine living in a racing environment. Even slight modifications, such as improved airflow through the use of a larger carburetor, the addition of improved exhaust, and ignition systems will enable an engine that has very limited internal modifications to develop more power, have an expanded rpm range and, subsequently, a greater need for fuel to supply these even limited modifications.

Engines for the weekly racer can range from a bone stock motor complete with air cleaner and mufflers to a highly tuned 500- to 600hp engine with very specialized fuel system needs. The weekly racer also has to deal with a variety of fuels, ranging from pump gasoline, E85, or race gas and, at the outer limits of the fuel spectrum, alcohol. All of these factors dictate the complexity of the fuel system. The amount of load that system will have to bear varies greatly.

For the most part, the weekly racer running at the local bullring will have a fuel system that is just a warmed over OEM system. Many of these race cars began life as daily drivers, never designed to be consistently driven at or near maximum power levels. Since the needs of the racer are so much different, stock fuel systems must be modified and improved to sustain the power requirements.

A typical short track fuel system is fairly simple. It includes a fuel tank or possibly a fuel cell, fuel lines, a fuel filter or two, and a fuel pump. If electronic fuel injection is being used, the system will also include fuel injectors and a computer. If the fuel system is supplying a high-power engine, the use of a fuel pressure regulator is almost a certainty, which may include a return line to the fuel tank. In those cases, you have fuel traveling from the tank to the engine and a line to route fuel that is bypassed from the regulator back to the tank. It boils down to a simple equation: The more power the engine produces the more complex the fuel system.

Buying Fuel
Regardless of the system's complexity, it all begins with the point where you, the racer, buy your race fuel. This is a critical point in the fuel system that's often never given a second consideration, but it's just as important as any part of the fuel system on the car. It's at this point that racers begin to really control the fuel system, and we all know that racing is all about control.

The simple action of transferring the fuel from the point of sale to the race car can and does contribute to variation in the fuel system. The fuel may only be exposed to one or possibly two containers between the point of sale and the race car. Devices such as funnels and fill lines that may be dirty or have been exposed to water, or through the mixing of old fuel and new fuel will contaminate fresh fuel.

The key is to treat your race fuel like you would treat the fuel that you put in your body. Keep it clean; make sure the containers you transfer fuel in are clean on the inside and the outside. Keep the fuel from becoming exposed to light and keep it cool.

Aside from the hopefully obvious safety aspects, poor fuel transportation and storage techniques can effectively take away some of the power producing components of the fuel. And I can think of very few racers who feel that they have too much power.

For example, everybody enjoys a sunny day but your race fuel likes dark and cool places and you should remember that. Fuel, especially gasoline, should always be stored in containers that do not allow the sunlight to reach the fuel. Most fuels are light sensitive and exposure to sunlight can and will damage the fuel. Prolonged exposure to sunlight can cause some race fuel to break down and some of the components to separate and once this happens it can't be undone. You can't just shake the container to mix the fuel components back together.