Porsche 2012 911 GT3 CUP Technical Manual page 43

Attention: The fuel pumps should not be activated under any
circumstances if tank-engine quick release couplings are
disconnected. Fuel pressure peaks in the system can cause
leakage, and in the worst case the system pressure can exceed
the burst pressure of the fuel filter.
4.2.1. Pressure regulator
The 911 GT3 Cup is equipped with a returnless fuel system. Due to this
design fluctuation in fuel pressure is possible. The average fuel pressure
over one complete lap should not be lower than
4.8 bar
40