Fuel Pump Rewire Options

[99Spyder]

This weekend's project was rewiring the stock fuel pump with 10ga wire straight off the battery and adding a 8ga ground. I have always heard this is a worth while mod but never read what kind of gains should be expected. Take a guess at what my results were.

*Note: Pulls were three days apart with very similar intake and coolant temps(aka no fuel trim alterations). In fact I found a portion of the log where I was in the same gear with the same intake temp, and the exact coolant temp~freaky~.

[99Spyder]

My Observation: I am running O2 feedback on the wideband. The corrections that I was seeing after the rewire on average were 5%. That is, to meet the target air/fuel ratio the ecu was pulling 5% fuel from the stock fuel map.

Now after thinking about this... I am still running the stock FPR. If rewiring increased the fuel flow, but I did not change the tune to allow more fuel through the injectors, wouldn't I just be returning more fuel to the tank? Maybe my 5% increase was from slightly overflowing the FPR resulting in a pressure increase.

I guess it is time to slowly crank the boost until the AFR falls off