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Rb26 Fuel Pressure

mr_rbman

By mr_rbman,
in Engines & Forced Induction

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mr_rbman Grand Master

mr_rbman

Posted
Posted

now I've searched and come up with nothing, surely this has been discussed and its my search techniques that need improvement.

Have an aftermarket fuel pressure regulator and I'm just after what the fuel pressure should be at idle?!

Cheers

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https://www.sau.com.au/forums/topic/457099-rb26-fuel-pressure/
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scotty nm35 Grand Master

scotty nm35

Posted
Posted

At idle it changes depending on the vac generated, hence why the base pressure is always set with the vac line disconnected. Should be around 40-45psi, depending how much boost you want to run. At idle the pressure will likely drop to 35-40psi once you hook the vac line back onto the reg.

GTSBoy Grand Master

GTSBoy

Posted
Posted

so standard turbos with the restrictor removed running 13psi approx. you would think around 40-45psi should be fine!?

Note it actually has nothing to do with the state of your turbos or boost level that you are running or planning to run right now. What matters is that the pressure should be set to the same base as your stock regulator, which is notionally 43 psi which is right in the middle of that 40-45 psi range. Anywhere close to 43 should be fine.

If you choose to set it anywhere else (say 50 psi to allow for more hectic boost levels) then you will overfuel everywhere unless the ECU is retuned to suit. The opposite is also true.

The ability to set the base pressure somewhere other than stock is only useful for those who are planning to run more boost, coupled with at least some of, but probably all of the following list. Injectors, ECU, pump, lines, surge tank, etc etc.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

GTSBoy is on the money, I just assumed you had an aftermarket ecu, as otherwise there is no point to change the reg.

Run high boost and you may need to drop your fuel pressure, as most pumps drop off badly in flow after 70-80psi.

mr_rbman Grand Master

mr_rbman

Posted
  • Author
Posted

thanks guys.

have nistune ecu, I won't get into it but the previous owner for some reason purchased large injectors, aftermarket fuel rail and adj. FPR. :no::angry:

I just want to make sure the base fuel pressure is right.

Thanks again.

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