Fuel Pressure for 383 LT1
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Instructor
Joined: Mar 2013
Posts: 163
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Fuel Pressure for 383 LT1
I am performing the final assembly of newly built '95 383, and I'm wondering where I should set the fuel pressure. I have an Aeromotive adjustable regulator, FIC 30# Bosch 3's, racetronix pump, and the equipment to tune. All of the instructions I have found for adjusting the pressure deal with doing the physical adjustment then testing. What I don't get is this - Shouldn't it perform it's best at what it is programmed in the computer to perform at? For instance, if it is programmed for 47 psi, and it is set to 47 psi, it should be good right? Likewise with all things being equal on a fresh build, if it is set to 60 psi in the computer and regulator, it should be good. I know the deal with better atomization at higher pressures, but at what point does the pressure become too high for the lt1?
Drifting
Joined: Aug 2010
Posts: 1,704
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if you raise too much the pressure with an hi flow pump you can overfill your engine,even if bigger in displacement...resulting in a rich condition that kill the tune causing the ECM cut the injectors pulse width to match the fuel ratio...i think you have to retune your VE to match injectors size (bigger) displacement (bigger) and fuel flow rate (larger )
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The fuel pressure affects the flow rate of the injectors. The ECM needs to know what the flow rate is so that it can calculate an appropriate injector pulse width.
All injectors are rated at X flow rate at Y pressure. Start with the rated pressure. Then tune for good performance. That might mean adjusting the pressure, but might not. You only need to change the pressure if you can't get a good tune in the ECM. That said, some people find it easier to adjust the pressure rather than change a zillion parameters in the ECM.
All injectors are rated at X flow rate at Y pressure. Start with the rated pressure. Then tune for good performance. That might mean adjusting the pressure, but might not. You only need to change the pressure if you can't get a good tune in the ECM. That said, some people find it easier to adjust the pressure rather than change a zillion parameters in the ECM.
