So I am running into a problem with fuel pressure on my car. Here is the current setup:
2017 Camaro SS 1LE
ARH Catless headers
Procharger D1SC with 4.25" pulley
LT4 HPFP
LT4 injectors
JMS BAP
The car already had the LT4 LPFP since it is a 1LE car. Now here is the issue. When I updated the fuel system with the tuner (who has been amazing) we had hoped to be able to get around E60 with E85 and be able to make around 700rwhp. For some reason the HPFP pressure is dropping off. Low side stays solid and in the 67psi or higher range, but sometime after the car crosses the 5100rpm point the HPFP side drops from the 2800psi down to 2250psi at the 6500rpm shift point. Because of the HPFP dropping off it is limiting me to E40 and leaving some power on the table.
I thought maybe it was a defective HPFP but after speaking to the GM tech at the dealership I know he said they rarely fail and it is more than likely the ECM opening the high pressure bleed off solenoid on the HPFP allowing it to bleed off pressure.
What are we missing here? I have went thru the entire fuel system, the low side is solid and I even replaced the stock LT1 fuel pipe that has the restricted orifice in it for the non-restricted LT4 fuel pipe with no change.
Why am I losing HPFP pressure once I cross over 5000rpm?
Todd