Fuel What PSI from an in tank 255 or other high volume pump
- Thread starter DAVE94LIGHTNING
- Start date
Even the stock 88 lph fuel pump will reach well over 100 psi if you close off the return.
It's your [regulator] that makes that determination, not your fuel pump. Your regulator doesn't step the fuel supply down. It restricts it until the desired pressure is achieved and returns the excess to the tank.
I won't be closed off but it won't be regulated by the FPR directly. If a 4an line is "T" off the main feedline before the FPR what pressure would it see when flowing? Lets say the FPR is at 45 psi.
If the FPR is set to 45 psi then it will see 45 psi. Any volume of fuel that causes the pressure to exceed 45 psi will be returned to the tank by the regulator.
If for instance, you should put in this [T] and leave that line open then the regulator won't do anything because the fuel volume is escaping and the system will never build to 45 psi. If you close this off, the regulator will begin bypassing fuel once it reaches 45 psi.
Thank you. So even the psi in the lines before the fuel rail is maintained at the same pressure as the overall system. Exactly what I needed to confirm. Thanks.
With the regulator set to 45 psi in a closed system, the entire system will run at 45 psi until you begin to exceed the pump volume.
This is a good read if you're going to be working with fuel system components:
I'm just jetting my nitrous systems so I needed to know the jet sizing and it is based on psi. I wasn't sure if the rails/injectors alone were pressurized to the set psi on the regulator such as using the schrader valve to pull fuel of if the feed line pre regulator was also at the same psi. Thanks.
Yeppers. So long as you have enough fuel pump you should be golden.
Do happen to have a method of measuring your air/fuel ratio once it's installed?
