Foam baffling serves two important purposes in a fuel cell. First, it reduces fuel slosh inside the bladder, making for more constant fuel delivery. Second, it prevents electro-static building inside the bladder from igniting and causing an explosion. These dual attributes make foam baffling both an important performance AND safety feature.
Foam can come in several varieties, depending on the application and desired density. To this, foam is usually identified by its "color". For most racing applications you'll find either Blue, Black, Red, or Yellow foams. Harmon Racing Cells only uses "Yellow" foam for our racing fuel cells as it is tends to be the longest-lasting and has a high chemical resistance to modern fuels. This makes it compatible for use with racing fuel, standard pump fuel, and diesel. Similar to our fuel cells, this foam is designed for use with hydrocarbon fuels ONLY and is not suitable for use with alcohol, methanol, or fuels with similar additives.