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91BLOWNBIRD
08-15-2009, 10:27 PM
When is it needed to adjust the fuel pressure on a SC?

pearl95sc
08-15-2009, 11:26 PM
Only needed if you're planning on tuning poor man style, or if you are wanting to tune with a higher pressure in order to shift the duty cycle and get a lil more out of your injectors.

fastsc92
08-15-2009, 11:46 PM
Only needed if you're planning on tuning poor man style, or if you are wanting to tune with a higher pressure in order to shift the duty cycle and get a lil more out of your injectors.

Not always true.

Adjusting fuel pressure is used often when upgrading injectors to other than a Ford brand. The reason for this is that Ford injectors are rated at 39.5 psi, so for example 30lb injectors are rated to flow 30lb's per hour at 39.5 psi. When upgrading to a Lucas or a Seimens type injector, they typically rate their flow rates at 3 Bar, or, 43.5 psi. In this situation, you would use an aftermarket regulator in order to dial in 43.5psi static pressure.

You can use a fuel regulator to "tune' (as stated from pearl95sc) but most of the time this only works for a short amount of time. For example, if you adjust it to add more fuel, you're adding this fuel globally, where you only really need the extra fuel under WOT, high RPM conditions. This extra fuel seen at part throttle would be trimmed out by the computer's adaptive control since it'll sense an overly rich condition in closed loop, and over time you'll be back to square one again.