phunk

it should actually have 52 psi 100% of the time if you are not running a return fuel system.

if you have upgraded the fuel pump, it wouldnt be strange to see a little pressure spike at idle. if the idle pressure spike is really high, there are ways to correct it. A spike of up to 6psi or so at idle I would ignore since the o2 feedback will be able to handle this. Past that, I would consider making some modifications if there are issues with consistency in idle A/F.

it also wouldnt be strange to see pressure fall a few psi towards redline on boosted cars as restrictions in the factory plumbing start to become noticable. Since the regulator is before these restrictions, the regulator doesnt see the pressure drop or react to it. This is one of the reasons for a RFS and putting the regulator up front. More than 4-5psi of fuel pressure drop is where i would strongly consider upgrading the fuel system. Fuel pressure drop means you have reached the edge of the existing fuel system, and the edge is unpredictable and inconsistent, and some days the drop could be quite greater than others and start causing big problems in the A/F ratios near redline.

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