chief455

iTrader: (21)

car is tuned with a single Walbro and I'm adding another pump activated by boost.

LT1, 383, D1SC, 12lb, 60lb injectors, factory rail mounted regulator.

made 560rwhp on dyno - but driving it the car loses fuel pressure at WOT when boost goes up fast an toward 10lb

otherwise the tune is really nice - just falls short on fuel volume it seems.

When the added fuel comes in under boost - will the car go rich now?

will the injectors just flow it through and excess go back the return line?

how could added fuel under boost (needed) impact my tune?

flame

iTrader: (13)

If the pressure was dropping when it was tuned it will be rich once the pressure holds steady. In essence your injectors were becoming smaller as the pressure dropped. Now that the pressure is there they will allow more fuel into the motor.

chief455

iTrader: (21)

not sure - it was tuned / dynoed before I bought it and right after the single Walbro kit was installed a few years back. might have been on the edge but they did not know..no air/fuel on the print out, only air temp and humidity.
I have driven it more now and may have found the pressure weakness - previous owner put a few hundred miles, thought it ran perfect - which until the fuel drops way out there at WOT - it does.