The Walbro 255 In-Tank Fuel Pump is the most popular performance fuel pump on the market. Its used in everything from factory cars, to full race cars. A single pump can support 500hp, and if you need more, you can run 2, or 3 together. This pump flows 255 liters per hour, well over a factory pump, supplying additional needed fuel to race engines making more power than they were designed to from the factory.