The trick is to get the fuel...
The trick is to get the fuel from the tank located in the rear of the car to the engine in the front. Simple? Consider that the car will go through a number of angle forces and the g-forces while racing, both of which impact the fuel system.
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.
Sunlight can cause a rapid...
Sunlight can cause a rapid degradation of a fuel's chemistry. While the use of white plastic or translucent fuel containers may be fine for alcohol, gasoline should be transported in containers that prevent sunlight from reaching the fuel, like these blue ones.
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.
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.
A couple of typical engines...
A couple of typical engines used in a Saturday night racer. Both use the engine-mounted mechanical fuel pump. However, the motor in the this car uses an inlet line that attaches to a fuel manifold (red) hose that feeds the carburetor.
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.
This car is using braided...
This car is using braided lines attached to the inlet line. Two very different ways to route the lines to the carburetor from the fuel pump.
We need to remember that however...
We need to remember that however we configure the fuel system, we need to make it easy to work on. Make the system components accessible, and your maintenance and tuning life will be much easier.
This team is pumping out the...
This team is pumping out the old fuel trying to diagnose a fuel problem. This type of activity is sometimes unavoidable. In this case, it was due to some bad fuel getting into the car. Once it was removed and replaced with some fresh fuel, the problem went away. Remember, your fuel is one factor that you can control.