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Fact or Fiction?
"Super Late Models can run longer distance races without a fuel stop
because they have much larger fuel cells than Winged 410 Sprint Cars."
Have you always thought that's the reason? Read on.
We have some information that may surprise you.
First, let's establish the basics.
Super Late Models use racing gas. Sprint Cars use methanol.
So what, you ask? Let's take a look at some interesting information you may not know.
Fuel Facts
- Pump gas is the classification of any readily available pump fuel with an octane rating of less than 100. And any fuel with an octane rating over 100, is classified as race gas.
- Race gas is gasoline with additives to increase octane. Additives can include lead, ethanol, and methanol.
- Methanol has less energy content than regular gasoline, so vehicles get about half the mpg out of the fuel.
- Methanol is less volatile than gasoline, greatly reducing the risk of explosion or flash fire.
- Methanol burns at a cooler temperature than gas, which makes the engine run at a cooler temperature.
- Methanol does not evaporate or form vapors as readily as gasoline does, and methanol vapors must be four times more concentrated in air than gasoline to ignite.
- Unlike gasoline fires, methanol fires can be extinguished with water.
Class Comparison
- Super Late Models use a Carburetor to mix the fuel and air for combustion. A carburetor relies on the vacuum created by the engine to draw air and fuel into the cylinders. The throttle can open and close, allowing either more or less air to enter the engine. This air moves through a narrow opening called a venturi. This creates the vacuum required to keep the engine running.
- Winged Sprint Cars use mechanical fuel injection. After pulling fuel from a vented fuel tank, the fuel is delivered through a barrel valve that controls the amount of fuel with the position of the air valve. Fuel goes through the barrel valve, then through fuel lines, directly to the intake system feeding each cylinder. For tuning, simple jetting changes control how much fuel enters each cylinder. Air is controlled with butterfly valves. Mechanical linkage connects the butterflies to the barrel valve. When the butterflies are opened, providing more air to the engine, the barrel valve is opened, providing more fuel to the engine.
- Both classes have a few different fuel cell sizes available, however they only vary by a couple gallons. Our comparison will use a typical size found often in the pit area.
Now let's take a look at the chart below and see how all that information plays out when comparing typical feature events for Winged 410 Sprint Cars, Winged 305 Sprint Cars and Super Late Models. We even throw in the average passenger car for some extra fun.
[Click the image to enlarge]
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