In situations where high load is demanded by an engine (like rapid acceleration or driving at a higher speed), the fuel pump increases the fuel flow rate and pressure to meet the engine requirements. For a regular engine, a fuel pump usually runs somewhere between 40-60 PSI (pounds per square inch). But, in high-performance engines, you might need pressures greater than 100 PSI for the appropriate delivery of the fuel. High-flow pumps — Walbro pumps are prime examples of this — are built to flow over 300 liters of fuel per hour, which means they can more than keep up when the demand is pushed to the extreme in a performance vehicle.
Under heavy load, the pump motor pulls more current, typically an increase from 5-6 amps in normal operation to 10-12 amps when under demand. Increasing tanker power allows the fuel-pump so that they can maintain sufficient fuel pressure throughout, thus avoiding fragile disgusting-prime conditions that lead to detonation and/or scorching the engine. According to industry reports, inadequate fuel supply under open-dimension high load may decrease engine efficiency up to 20% and even run the engine without fuel cooling to induce severe damage.
In addition, voltage stability plays a big role in the performance of a fuel pump under load. Having a constant 12 volts means that the pump can draw the power it needs to work without overheating or stalling. High-load performance pumps also frequently feature carbon elements made from no-nonsense high-strength materials, like tougher brushes or high-grade rubber seals, to hold electrical and mechanical stresses more efficiently. These materials withstand heat and friction, which means wear is less even if the pump is continuously exposed to extreme conditions.
Load always exerts a pressure on the fuel pump, so the fuel pump can become hot at a high load, which is workable with a good cooling or with limiting the running time otherwise it will fail. Fuel that is submerged in the pump provides a cooling function to the pump, which evaporates power dissipated by the pump operating at high load. But relying on the low-fuel coolant effect takes it all away, which will raise the pump temperature and put it in danger of overheating. So experts recommend a minimum of a quarter tank, the reasoning being that if there is too much heat from the pump, it can lose as much as 30% its lifespan.
Several manufacturers such as Bosch and Delphi design their high-performance fuel pumps to include pressure relief valves in order to avoid an excessive pressure build-up capable of damaging internal pump components. These valves control pressure spikes, especially when driving at high speeds, releasing excess pressure to avoid inconsistencies in fuel delivery to the engine.
The right Fuel Pump is crucial for reliability when it comes to high-load performance, otherwise underperforming pumps can ruin efficiency and—more importantly—engine safety in demanding situations.