GAS VW/Audi EA113 FSI HPFP Inlet, High Flow

When we set out to find every fuel system restriction in the FSI platform, we left no stone unturned. After taking apart the HPFP we were shocked to find that the inlet measured out at less than 1.5mm! When compared with OEM HPFP inlets on the TSI platform as well as other VWAG platforms such as the Audi 3.0T, the difference was staggering. The FSI inlet is microscopic by comparison.  These suspicions were backed up by logs from 3 big turbo MK6Rs and a big turbo B7 A4 on our in-house Mustang dyno. At higher engine speeds the fuel flow into the pump can't keep up, causing low-pressure readings to drop sharply as pump demand increases. This issue is worked around by larger in-tank pumps or HPFP inserts, but even with APR HPFPs, Hellcat in-tank pumps and upgraded controllers, the same issue persisted. The LPFP pump simply cannot flow enough fuel into the HPFP to prevent the high-pressure pump from being drained faster than it can refill. By replacing the inlet with our high-flow version w