Pressure stability is the core indicator. The electronic fuel injection system requires a constant pressure of 3.5-4bar (the carburetor only needs 0.3-0.7bar), the pressure fluctuation range of the vane pump needs to be controlled within ±0.2bar, while the deviation of the scroll pump reaches ±0.8bar. The EFI technical manual of General Motors points out that after installing the Bosch 044 vane pump, the air-fuel ratio fluctuation of the 4.6L V8 engine at 5500rpm decreased from ±1.2 to ±0.3, and the torque output increased by 6.7%.
The degree of flow matching affects fuel efficiency. The peak flow demand of the 2.0L inline-four engine was modified to be 120L/h (naturally aspirated) or 180L/h (turbocharged), and the excessive supply led to an excessive oil return of 17%. The actual measurement shows that when the pressure regulating valve of the Walbro 255L/h pump is not modified, the idle oil return ratio reaches 73%, and the annual fuel consumption increase is $142 (calculated based on 20,000 kilometers per year). A reasonable solution is to use a Aeromotive 13135 pressure regulating valve to reduce the return rate to below 35%.
The built-in pump has a significant advantage in heat dissipation. The operating temperature of the Fuel Pump submerged in the fuel tank is less than 65℃, while the temperature of the external pump in the engine compartment is greater than 98℃ under traffic congestion conditions, resulting in a shortened motor life of 32,000 kilometers (an average of 120,000 kilometers for the fuel tank type). The Ford Mustang modification case shows that the external solution triggers thermal protection shutdown after continuous operation for 45 minutes in a 32℃ environment, while the internal solution can operate for 140 minutes under the same conditions.
Pulse damping design suppresses interference. The fuel injection pulse width of the electronic fuel injection system is only 2-20ms. The pressure pulsation of 0.01ms in the plunger pump will cause the fuel injection volume error to reach ±11%. The Bosch 063 solution integrates a 0.6L pressure storage tank, reducing the pressure amplitude by 82%. The actual measurement of the modified Corvet C3 has confirmed that this design enables the air-fuel ratio control accuracy for the entire range from 800 to 6000rpm to reach λ=1±0.05.
The intelligent regulation and control system optimizes energy consumption. In the Holden 5.0L V8 modification project, the variable-frequency pump has a power of only 35W at idle speed (85W for the fixed-frequency pump), reducing the generator load by 28%. The supporting ECU (such as Haltech Elite 2500) dynamically adjusts the flow rate based on the MAP signal, saving 9.4% of fuel in urban working conditions. The renovation cost of the entire system is approximately $940.
Full system compatibility determines success or failure. When using E10 gasoline, it is necessary to verify the material of the seal: the expansion rate of fluororubber (FKM) is only 3% (nitrile rubber 22%). Statistics from Bowser Tech Company in Australia in 2022 show that for modified vehicles without upgraded seals, the failure rate of the oil pump soared by 87% after 30,000 kilometers, and the average maintenance cost was $520. We recommend the Cummins 38R series kit, whose E100 endurance certification can cover the mainstream ethanol gasoline worldwide.