autoxLT4

I have recently acquired a very nice billet aluminum AFPR and I have a few questions. :rolleyes:

1. How is having higher pressure on the fuel going to help? Other than possibility of better atomization. The fuel rate should stay the same which is 24 lb/hr.

2. Will setting the AFPR at say 50 psi set any codes and how are the codes set?

Right now the car is running a K&N filter, Hypertech Power Progrmmer Plus, Accel Extreme 9000 wires and Bosch +4. Everything else is bone stock.

Thanks,
:cheers: :flag

vetsvette

I checked my stock pressure and adjusted the AFPR to the same level (47psi). Took it to the Dyno to fine tune it. Went as low as 45 and as high as 54 before settling in 52psi. Noticed a small increase at high rpm's (2-3hp) and was disappointed a h*ll. A $100 for the part and another C note for an hour of dyno time for essentialy no gain. Hoping it will help when I do my heads and cam. Still runs fine and did not lower MPG at all. (maybe even a small increase) :(

AquaMetallic94LT1

Go back and do the test again. I'll bet the hp gain is gone. The ECM needs to know how much fuel the injectors actually dispense so it can get the air fuel ratio to the correct value (14.7) for emissions purposes. It does this by constantly monitoring the O2 sensor and adjusting an internal parameter or parameters to keep up with subtle changes in the fuel system like a clogging fuel filter, failing regulator etc. Fuel pressure changes the flow rate of the injectors by the square root of the pressure change.