After the installation of the turbocharging system, the necessity of upgrading the Fuel Pump depends on the boost value, the type of fuel and the engine tuning goals. For example, in the Volkswagen EA888 Gen3 engine, the original fuel pump (flow rate 80L/[email protected]) when the boost value was increased to 1.5Bar, the pressure at full throttle dropped from 3.5Bar to 2.1Bar (a decrease of 40%), and the air-fuel ratio worsened from 14.7:1 to 16.2:1. The probability of triggering the ECU speed limit protection reaches 89%. After upgrading to the Bosch 044Fuel Pump (flow rate 450L/[email protected]), the oil pressure fluctuation is compressed to ±0.3Bar, the air-fuel ratio control accuracy is ±2%, and the horsepower on the wheels is increased from 290PS to 380PS. The return on investment (ROI) reached 240% (with a total modification cost of $1,500 corresponding to an average annual revenue of $3,600).
The demand for flow redundancy is positively correlated with the boost intensity. The Ford Mustang GT requires a fuel flow of 320L/h at a boost value of 2.3Bar. Even if the original pump (120L/h) replaces the high-flow fuel injector (ID1050x), due to the insufficient flow of the pump body, the standard deviation (σ) of the rail pressure still expands from ±0.5Bar to ±2.1Bar. The trigger frequency of the detonation sensor has soared from 0.2 times per minute to 1.8 times per minute. After installing the dual Walbro 450 pumps (with a total flow rate of 900L/h), the pressure fluctuation rate decreased to ±0.4Bar, the acceleration time from 0 to 100km/h was shortened by 0.9 seconds (4.1s→3.2s), and the concentration of fuel dilution oil decreased from 5% to 0.8%. NHRA race statistics show that the withdrawal rate of turbocharged modified vehicles without upgraded pump bodies is as high as 34% (with the original factory pump scheme) versus 5% (with the upgraded dual-pump system).
The temperature resistance of materials affects the reliability of the system. Under the turbocharging condition, the fuel temperature often reaches 95-110℃. The deformation rate of the original factory nylon impeller Pump increases from 0.02% at room temperature to 0.15%, while the deformation rate of the 316L stainless steel impeller of the AEM 320LPHFuel Pump is only 0.003% at the same temperature. Data from the Nurburgring 24 Hours Endurance race shows that the flow rate of racing cars without upgraded pump bodies decreased by 18% after the eighth hour, while the flow rate retention rate of high-temperature resistant pumps (such as Titanium T1000) throughout the race was > 99%, and the maintenance interval cycle was extended from 500 kilometers to 3,000 kilometers.
The intelligent regulation and control technology optimizes the dynamic response. The Link G4X ECU, in conjunction with the Bosch Motorsport HP pump, CAN dynamically adjust the flow rate at a frequency of 1000Hz through the CAN bus. During the pressurization transient (1.8→2.5Bar), the oil pressure response delay is compressed from 200ms to 35ms. The overshoot of the air-fuel ratio decreased from ±15% to ±3%. In the Subaru WRX STI modification case, this solution reduced turbo lag by 0.3 seconds, increased the acceleration time from 30 to 130km/h by 12% (7.8s→6.9s), and improved fuel economy by 9% (fuel consumption 10.5→9.6L/100km).
The economy needs to be evaluated throughout the entire life cycle. If the Fuel Pump of the basic turbine kit ($3000) is not upgraded, the average annual maintenance cost will increase by $1200 (including engine knock repair and oxygen sensor replacement). The total investment of upgrading the AEM 320LPH ($280) and the fuel cooling system ($450) is $730, which can reduce the 5-year maintenance cost from $6,000 to $1,800, saving a net of $4,200. However, if the boost value is only 0.5Bar and 91-octane gasoline is used, the original factory pump flow redundancy may meet the requirements (the measured oil pressure fluctuation should be less than ±10%), and at this time, the necessity of upgrading drops to 23%.
The decision on mandatory upgrade for regulatory compliance requires that the fuel vapor emission be ≤0.02g/test. The leakage rate of the original factory pump is 0.08g/h, which exceeds the standard by four times. However, the DeatschWerks DW300c (with a leakage rate of 0.005g/h) can pass the test 100%. California CARB certification data shows that the failure rate of annual inspections for vehicles using uncertified pump bodies is 78%, facing fines starting from $500, and the risk of insurance rejection increases to 65%.
Typical case verification: Among the users of the BMW N54 engine (original factory turbo), those who did not upgrade the pump body had a 42% failure rate of the high-pressure fuel pump after 30,000 kilometers (maintenance cost $1,800 per time), while after upgrading the Precision Raceworks 525 pump, the failure rate was reduced to 3%, and the average annual holding cost was decreased by 58%. The conclusion indicates that when the boost value is greater than 0.8Bar, ethanol Fuel is used, or the target horsepower increase is greater than 30%, Fuel Pump upgrade becomes a mandatory option; The original factory calibration plan for low supercharging can be postponed, but the PID value of fuel pressure needs to be continuously monitored (intervention is required if the fluctuation is greater than ±15%).