Whipple fuel pressures...tuning?

[hquick]

Hi All,
as I have the older style whipple without the extra injectors, I'm wondering how I can tune to suit the extra fuel pressure created by the 'boost-a-pump' setup?
I guess I need to adjust my injector flow rates?
Is that correct?
normal running fuel rail pressure is around 58psi. Under acceleration it gets as high as around 80psi.

[joecar]

Howard, you would need to calculate each IFR point at it's corresponding pressure.

[hquick]

Mmm...that's what I thought.
so, I should be able to check the pressure at each MAP Kpa and calculate it from there?
I can see this is going to be very difficult!
The sooner I get the marine intake and 42lb injectors installed, the better.

[hquick]

Is there anything I can log to help me calculate this?

[5.7ute]

Have a look in the tutorials there is a how to on logging the fuel pressure. As for where you can modify the ifr table as it only goes to 80 KPA I dont know. You may have to modify your pump pressure to give a directly proportional pressure increase to boost pressure.

[Lextech]

Hey Howard, Get all of your bits and pieces gathered up. Take a day off of work, and install that Marine intake. Get rid of that Whippletronics stuff. You are just going to be chasing your tail. Even when you do get the Whippletronics sorted out, You will still have a good Marine intake sitting on the work bench.

[hquick]

Yeah...I know you're right Lextech!
I guess that's what I'm going to have to do.

[joecar]

If you you could install a MAP-referenced fuel pressure regulator (requires a return line) with a constant pressure pump, then you could set the IFR flat across.

In the meantime, you have to log your fuel pressures at various MANVAC values (and see if there is consistency) and then calculate each point of the IFR table using the logged fuel pressure vs MANVAC; at boost, MANVAC goes negative, so I believe the PCM uses the IFR value at MANVAC=0... (can someone confirm this);

There's a pid for MANVAC... and MANVAC is defined as BARO - MAP.