Low fuel pressure and sluggish driveability on the street prompted us to remove the coupe's Alumastealth fuel tank in an effort to determine what was causing the condition. What we found inside was this 100-Micron fuel filter packed solid with pump-fuel residue. It had gelled at some point and adhered to the Alumastealth's walls. According to engineers we spoke with at VP Racing Fuels, introducing tankfuls of higher-octane race fuel apparently broke down the residue over time. We consider this a prime example of why it's important to use good filters on a big-horsepower fuel system.