The choice of a fuel pump for high-altitude conditions involves the consideration of multiple aspects affecting engine efficiency. When you get above 5,000 feet in altitude the air pressure is lower and all that affects what is known as stoichiometry (simple description: chemical balance of fuel combustion inside a regular combustion engine). Research proves that for every 1,000 ft of elevation gain engines at high altitude can lose up to 3% power so selecting a suitable Fuel Pump is vital in order to prevent fuel delivery and engine efficiency from suffering.
For operation at high altitudes, the pump should deliver a slightly richer fuel mixture to offset loss of pressure in thinner air. The flow rate is gauged in litres per hour (LPH) and requires to be adjusted according to the engine specifications. This means that an engine running at 10,000 feet might require a pump capable of flowing as much as 110 percent associated with the fueling system flow rate to maintain stoichiometry whereas at sea level this instantaneous % load may be closer to only ~85–90%. Industry pros suggest 255 LPH and up to 340 LPH pumps for higher altitude performance cars so you know your engine won't run lean leading to potential internal damage.
There is a famous quote INAMG, Carroll Shelby who once said “ Horsepower sells cars. At high altitudes especially, engines need more than horsepower—it needs fuel in the correct amount and reach to sustain torque. Then there are the extreme cases, such as racing events like Pikes Peak International Hill Climb where elevations can exceed 14K feet and racers need every inch of power or torque but still have to survive running full bore at a fraction of standard atmospheric pressure.
One of the things to consider when choosing a pump is the specs as far as fuel pressure. High-altitude conditions usually require fuel pumps with pressure outputs that range anywhere from 40 to 70 psi, depending on the ignition system of your car. On top of these advantages, modern electric fuel pumps with variable speed control present a more efficient solution for different altitude conditions eventually aiding in saving up to 15% on the used jets power provisions.
So, for those asking the question "If a choose fuel pump to optimum highland range in what is most decisive issue? It all goes back to finding the right balance of flow rate and pressure for whatever duty cycle is required in those, say, low-oxygen environments. Protecting a fuel pump from dropping or raising as altitude changes is critical in order to prevent loss of performance and potential damage to the engine.
To know more about how to select the appropriate fuel pump please visit this Fuel Pump.