This is a mod that the turbo Buick guys use to get full alternator voltage to the fuel pump. It basically bypasses the factory wiring harness with a heavier gauge wire running directly from the alternator to the pump.

I'd like to know everyone's opinion about the effectiveness of this modification on a stock naturally aspirated LT1.

Is there any gain to be had from increasing the amount the stock pump can flow. My roommate installed a Walbro 305 in his 98 Z28 (LS1 M6) after his stock pump burned up due to fuel starvation, and he swears the car picked up a lot of power from the pump itself. Wouldn't the increased volume of fuel from the new pump be offset by reduced injector pulse width once the ECM sees a rich reading from the 02 sensors? I would think so, but his experience was the opposite.

What do you guys think?

 

The PCM isn't going to reduce pulsewidth during WOT, so the extra flow will help you there if you are lean beforehand. If you're rich, it's just going to waste fuel.

I have a buddy in my club that has a "Boost-a-pump" that ups the voltage to the fuel pump for when he's running nitrous, so I guess it has the same (or better actually, as it's adjustable) effect as the mod you mentioned.