The Nostrum Subaru FA20 High Pressure Fuel Pump (HPFP) provides a ~40% increase in fuel capacity vs. the stock pump. It is ethanol compatible up to E100, capable of 600+ whp on E85.
To take advantage of your new pump’s increased fuel capacity, you must also upgrade your vehicle’s intank (low pressure) pump. Fuel system limitations due to the low-pressure pump frequently are seen at high RPMs and high-power levels
The HPFP needs a constant supply of fuel pressure (around 4 bar) at its inlet in order to avoid cavitation. If the in-tank pump cannot supply sufficient fuel pressure/flow, it will starve the HPFP at higher RPMs.
Functionally, your vehicle does not require calibration changes to operate with the Nostrum HPFP. With the Nostrum HPFP it is possible to request higher fuel rail pressures at higher RPMs, however Nostrum does not recommend requesting more that 170 bar of pressure.
WARNING: Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to https://www.P65Warnings.ca.gov/passenger-vehicle.