# Raising Fuel Pressure - Adjusting Fuel Map

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Hi,

I have ID 1300cc Injector's, 2 DW 340 Pump in a Surges Tank & I can add 1 more, -8 Feed, No restricting

Fuel Pressure is stable and climbs with boost through-out Rpm

I'm at 85% DS @ 7200rpm, will be running it to 7800 rpm

I'm making 802whp/584wtq@7200 with Vortech SC

So Question: If I raise fuel Fuel Pressure ( say 5 psi ) what % would I reduce the Fuel Map accross the board?

Is there a Basic Formula?

Any Help is Greatly Appreciated!

Thanks,

Tim

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If you are in modelled mode with accurate injector data

Only raising the working pressure in the settings would do it.

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The effect of fuel pressure is relatively small.  If you are not in modelled mode then your flow will increase by the square root of new press/old press.

So for example if new pressure was 50psi and old pressure was 45psi the flow increase would be sqrt(50/45)=1.054, or roughly a 5.4% increase in flow.

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Yes, I am in Modelled Mode.

Great! That is a Simple equation.

Thank you so much,

Tim

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• 1 month later...

If I could add jump onto this, if I'm in multi-modelled mode and I want to raise my base fuel pressure from 43 to 50spi what is the best thing to do? I increased my fuel pressure value in the injector settings by 7 but that didn't seem to even me out. Thanks.

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If everything else was correct (deadtimes, flow rate, fuel table etc) then you should simply be able to increase the pressure, and it should actually recalculate correctly.

However, if you're not finding that, then one or more of your other settings was incorrect, so you've got some of that incorrect value baked into your fuel table, and you'll going to have to retune.

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2 hours ago, VegasAWD said:

I increased my fuel pressure value in the injector settings by 7 but that didn't seem to even me out. Thanks.

You adjust it in the Fuel main settings, not in the injector settings.

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You adjust it in the Fuel main settings, not in the injector settings.

Ahh, thanks for the help!

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You adjust it in the Fuel main settings, not in the injector settings.

Sorry, for the silly questions but my setup is fp sensor-based, therefore, do I not have to make any changes to the tune? Obviously base pressure setting goes away with that setup.

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Correct, if fuel system type is set to fp sensor then fuel pressure is already taken care of, you shouldn’t need to change a

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3 hours ago, Confused said:

If everything else was correct (deadtimes, flow rate, fuel table etc) then you should simply be able to increase the pressure, and it should actually recalculate correctly.

However, if you're not finding that, then one or more of your other settings was incorrect, so you've got some of that incorrect value baked into your fuel table, and you'll going to have to retune.

Sorry, I didn't see this post initially. Thanks!

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