Raising base fuel pressure – Best tuning approach for the main fuel table

Hi all,

Is there a way to calculate or compensate the main fuel table with a higher base fuel pressure? What should be consider when doing this change in base fuel pressure? I’ll be going to the dyno but I was wondering if there is a smart tuning approach for this change.

I’m running around 85% duty cycle at the moment and I want to raise the base fuel pressure to get more out of it. Fuel pump is up to the task it’s a Weldon 1100-A pump. Injectors are ID1000 @ 3 bar (43.5psi) base pressure.

Using a Vipec V44 on this setup.

Fuel equation: Load = Map

Fuel table y-axis load: TPS

Ignition table y-axis load: MAP

Thanks.

Dolfo

You can calculate what the fuel flow will be at the new fuel pressure using the Bernoulli equation:

New Flow = Reference Flow * √ (Final Pressure / Reference Pressure

Injector Dynamics actually list the flow at various pressures though so your job is even easier. I'd suggest you start by calculating the flow difference at your new pressure. Let's say that you raise the fuel pressure and the injector flow increases by 25%, then I'd make the opposite change to your entire fuel map and this should have you pretty close before you start tuning.