Very high RPMs does make even more sense in terms of fuel flow demand from the pump — but the pump must also be designed to be able to meet those increased requirements for flow and pressure. Many standard fuel pumps have flow rates set for ~150-200 liters per hour (LPH) – fine for [low] RPM but not for high performance engines, which need high pressure at high RPM. When you are looking at high RPM scenarios, you need a pump to supply more fuel without drops in pressure. Performance fuel pumps, such as those from Walbro, are designed to supply flow rates greater than 300 LPH so that even under high RPM conditions, the fuel flow will not prevent the engine from making power.
It is important to get stable fuel pressure at high RPMs to prevent lean conditions and engine knock or even destroyed engines. As many high-performance fuel pumps are tuned to run over 100 PSI, they will maintain accurate fuel pressure during tip-in or when under hard driving conditions. Research shows that high RPM ready fuel pumps reduce the chances of a pressure drop by as much as 15% compared to a standard pump; important for engines which run at high RPM for extended periods of time.
Well, electrical voltage stability is another factor that affects a fuel pump’s ability to handle high RPMs. That’s right: The thing to remember is that performance fuel pumps do best on a constant supply of 12 to 14 volts. This is extremely detrimental in high RPM engines as a small voltage drop can cause a reduction in pump output of as high as 20%! And consistent fuel delivery is key. A lot of tuners suggest the use of a higher output electrical system as well, including the wiring and alternator, to make sure that the fuel pump is supplied with sufficient power during high demand.
Another important consideration is heat management since the higher the RPMs of the fuel pump, the more heat the fuel pump will generate. Performance pumps are sometimes made of special materials that allow for heat mitigation, like high-grade rubber or metal alloys which help combat heat wear and allow for maximum performance at higher temperatures. For example, Bosch’s high-performance pumps have built-in cooling systems that enable the pump to function at over 100 degrees Fahrenheit without overheating in extended high RPM use.
Adding a fuel pressure regulator is typical to allow the pump to respond to changing RPM demands. A flow regulator that adjusts the amount of fuel flowing to the engine based on engine speed, providing additional fuel when RPM is peak and limiting output when less is required. According to performance studies, the pressure regulator can be used to increase fuel efficiency by up to 10%, and to enhance engine response.
When a Fuel Pump is built to serve higher RPMs, there is enough constant pressure to deliver the right amount of fuel required for the tuned engine, providing necessary stability and avoiding damage in the case of high-load conditions. Constant voltage, heat management, & steady pressure all make a fuel pump high RPM capable in HIGH-performance vehicles.
